# Leviton D4DMX dimmer nightmares



## TorontoAlchemy

I run a black box theatre with satellite DMX dimmer packs.

We have:
2 Leviton DDS 6000 4-dimmer packs
5 Leviton D4DMX 4-dimmer packs

Here is the link on the D4DMX's
http://www.leviton.com/OA_HTML/ibeCCtpSctDspRte.jsp?section=15393

Of my 5 D4DMX packs here is the present state of their dimmers
#1-2 work, 2 don't (always turn on at 100%)
#2-2 work, 2 don't
#3-4 work
#4-2 work, 2 don't (1 receives no signal, 1 piggybacks on signal of another)
#5-3 work, 1 doesn't (allways on at 100%)

All 5 of these are less than 4 years old, and 2 of them are less than 1 year (#4 & 5!)

I have constant problems with these D4DMX. All sorts of bizarre things happen every time I change the hard patch. However once I have completed the new hard patch then everything runs fine for performances. But then for the next hard patch change the problems start all over again.

In contrast the DDS 6000 packs work perfectly and I have never had a problem.

I've spoken to the Leviton help line about this and they told me that these D4DMX's are made in China and apart from the brief manual which comes with the pack they don't have any technical information in English. It is all in Chinese (!). They said there is simply no tech help they can provide me (unless I speak Chinese)

These packs are the least expensive in the Leviton line and I now understand why they are so cheap. But I must admit I am very surprised that Leviton, a quality provider of high quality products, would stock something so crappy.

Anyway, just wanted to vent a little, but also to possibly save someone else from making the mistake I made with these. Stay away...stay far far away!

We're going to retire these soon (ie smash with hammer) and move to some of the 220v 12x1200 watt packs. 

Simon


----------



## Van

Sounds like some are stuck in non-dim mode. Is it a possible adressing problem ? I hate to knock Leviton < wait , no I don't> since thier kinda local , but the idea that they don't have any documentation for a product they sell seems a bit far fetched.


----------



## TorontoAlchemy

I think whats happening is that some of the circuitry components which regulate the flow of electricity from the source through the pack to the output are failing. I had hoped that I could simply locate the relevant component and replace it within the pack. But as I was told by Leviton, they don't have circuitry specs in English (I agree that sounds bizarre, but that's what I was told, and the techie I spoke to seemed to find it as bizarrely amusing as I do)

Speaking of amusing, my favourite funny story about these packs was when I was using a voltage meter to check one of the non-working dimmers. My voltage meter dutifully told me that there was a strong 110v coming out of the dimmer. "So why won't my light turn on!!!", I cursed and fumed at the dimmer. Eventually I realized that although there was a nice strong flow of volts, there were unfortunetly no amps coming out! Doh!


----------



## tony

TorontoAlchemy said:


> Eventually I realized that although there was a nice strong flow of volts, there were unfortunetly no amps coming out! Doh!


u cant get a reading on amps because
1. amps are relative to the load on the line
2. because u must place ur tester in series with the load
btw putting ur tester in the plug with no loads shorts the line thus blowing ur dimmer or channel or fuse
know ur stuff before attempting repairs or what so ever involving testing

also, as van said check your adressing since those dimmers dont use standard dmx adressing...not 1,2,4,8,16,32, etc
check on the internet for some archives of the manuals or something

-Antoine


----------



## TorontoAlchemy

I'm not sure that I understand what you mean by "not using standard dmx".

Here is the page to the manuals download http://www.leviton.com/OA_HTML/ibeCCtpSctDspRte.jsp?section=15393

As you can see, the manual is only 4 pages long.

I understand the difference between the "P"-programed cycle mode and the "A"-addressed dmx mode. Also I understand the differerence between setting the pack to 1-dimmer, 2-dimmers or 4 dimmers. And I understand how to set the starting dimmer # (ie A005 in the 4 dimmer option will give Dimmers #5, #6, #7, #8. 

Beyond that, there are no other control options.

Both myself and no fewer than about 20-30 lighting designers/techies have been cursing at these packs over the past several years, and I figure it's unlikely we've all missed something obvious. Although I would be happy to be proven wrong. 
Thx


----------



## tony

im sorry ..... I had the wrong info.(Landed on wrong internet page) :\
I thought the adressing was done with dip switches
anyway ... did you get them checked by an electronic tech?


----------



## TorontoAlchemy

Yesterday I had an electrician reviewing my breaker panel in order to give me a quote on some rewiring/adding some 220v breakers/etc.

He told me something about the action of dimmers that I had never heard before. 

I had previously thought that if I have a 500w light plugged to a dimmer, and I dim to 10%, then my power use was 50w (ie 10% of 500). 

Apparently that is not the case, and I continue to draw the full 500w. However only 50w is sent from the dimmer to the light, and the rest is consumed by the dimmer pack.

With these 600w dimmers there have been times when I would plug in 2x500w lights, but only dim them to 50% max. I figured as long as I was below the 600w output to the light I was ok. 

But now I wonder if perhaps the 1000w power draw on the 600w dimmer may have fried one of the circuits? I would have figured the 600w dimmer breaker would have tripped if I was overcapacity, but perhaps that only trips if my output to the lights exceeds 600watts?

On my bigger packs the per dimmer capacity is 1200 watts, and since I have never gone 3x500w on one of those dimmers perhaps that is why I have only had problems on the smaller packs?

Does any of this sound familiar to anyone? Is it damaging for a dimmer if you plug in lights that take it over capacity, even if you only output wattage to the lights that is under capacity?

Simon


----------



## soundlight

That's definitely a problem. The max that I would put on a 600W dimmer is a 500W bulb (to allow for cabling and other resistance points in the current flow). You should never put more wattage in lamps on a dimmer than the dimmer is listed for (by lamp wattage I mean total wattage of the maximum/full output of all of the lamps/fixtures on a dimmer).

For instance, if I have a dimmer that is 2400W total (600W/channel), I'd put one 500W instrument per channel on it at most. That leaves 400W for leeway. This is way more than needed, but I don't like to push the dimmers to far (yes, dimmers can be pushed to far, we've had some of our packs go because we loaded 2400W dimmers at 2400W, and that wore them out MUCH faster).


----------



## BillESC

It would appear that operator error rather than poor quality construction is the cause of the problem.

We have sold and installed NSI dimmers for over 20 years and their failure rate is one of the lowest in the industry.


----------



## soundlight

BillESC said:


> We have sold and installed NSI dimmers for over 20 years and their failure rate is one of the lowest in the industry.



That's why I like NSI stuff...their dimmers are virtually bulletproof. It's amazing how much abuse they can take.


----------



## TorontoAlchemy

Bill,

At the risk of sounding a bit defensive, and with due respect, that's not really the most helpful post, and is a tad dismissive.

While I agree that a poor workman blames his tools, at the same time I would gently suggest that if the problem is simply a lack of skill then a more skilled workman should be able to identify the cause of the problem.

I agree that NSI makes quality products, and previously stated as much. 

But in this case this low-end dimmer pack comes with only a 4-page manual, there are no circuitry specs available in English at NSI and no-one (including the posters here) has ever suggested that a 1000w light patched to 50% would damage a dimmer with a 600w capacity without ever tripping the internal resettable breaker and thus be the cause of the problem. 

In hindsight it may seem obvious (if indeed this is the cause, which is not yet proven), but that is why it is called hindsight.

I'm not the first person to post with satellite dimmer pack/DMX problems, and I've not seen this possible cause listed in any of the other threads. Nor have I seen it listed in any sort of FAQ or Troubleshooting section in any manual or website anywhere. So I hope that this shared "operator error" might prove useful.
Thx
Simon :-/


----------



## royl

You may have smashed them already. But a couple of questions come to mind only because I didn't see it in any posts. 

1) is the DMX line terminated correctly?

2) Is the power fairly noisy?

Noisy power can play havoc on any electrical system. And noisy and improperly terminated DMX line can play just as much havoc.

Royl


----------



## TorontoAlchemy

Royl,

I must admit that there have been times in the past when the DMX line was not terminated properly, but that is now fixed.

Regarding the "noisy power", I googled that and if I understand correctly it describes other electronic equipment on the same breaker feeding back interferance into the wiring? Is that correct? If so that is certainly a possibility as we've not had dedicated breakers for the dimmers in the past(although we have an electrician installing those shortly)

Is there an instrument one can purchase to measure "noisy power"?
S


----------



## BillESC

Simon,

If I came off as harsh, I'm sorry.

I simply can't understand why one would patch 1000w to a dimmer rated at 600w, the potential for trouble is too great.

It seemed to me to be like using a one ton chain motor to lift two tons but being sure to only lift it half way.....


----------



## SHARYNF

Leaving aside for the moment whether it is a good idea to put a 1000 watt lamp for instance on a 600 watt rated dimmer and run it at 50 percent, the information that your electrician is giving you does not apply to theatrical dimmers. Home dimmers probably work the way he is talking but theatrical dimmers do not. If he were correct that it would be impossible to run a full dimer rack on a electrical supply with an amp rating of less than the total load capability of the dimmers, and this certainly is not the case. 
These dimmers use a triac, and they work basically by turning off the current for a short portion of the cycle, depending on the desired setting, so in general terms at 50 percent, the power is off to the lamp for 50 percent of the ac cycle.
So it depends on how you are measuring, since it is correct that for 50 percent of the cycle, the amp draw is at the full rating, but for the other 50 percent it is not drawing anything. 
Sharyn


----------



## glenn

*Electrician gave incomplete information about dimmers*


TorontoAlchemy said:


> Yesterday I had an electrician reviewing my breaker panel. He told me something about the action of dimmers that I had never heard before.
> I had previously thought that if I have a 500w light plugged to a dimmer, and I dim to 10%, then my power use was 50w (ie 10% of 500).
> Apparently that is not the case, and I continue to draw the full 500w. However only 50w is sent from the dimmer to the light, and the rest is consumed by the dimmer pack.
> Does any of this sound familiar to anyone? Is it damaging for a dimmer if you plug in lights that take it over capacity, even if you only output wattage to the lights that is under capacity?
> Simon


1. The active component of these dimmers is a Triac (for smaller capacity dimmers - like 600w) or a pair of SCRs for larger capacity dimmers). These are very fast electronic switches. They only turn the power on and off (very quickly). They do not "consume" the power while dimming. Imagine if you flipped a light switch on and off very quickly - you get less light and and so use less power. So you are correct, that if you have a lamp dimmed to 10%, less power is used than the lamp draws at full. (probably not exactly 10% of the power though - it's a non-linear function). 
2. You may be technically drawing 500W for a few milliseconds of each AC cycle, but the average power being used is much lower. You can test this by putting a mechanical ammeter on the feed to the dimmer while the dimmer is set at 10%. You'll see the average current drawn is much less than the approx 4 Amps a 500 Watt 120V lamp draws. The breakers on the dimmer output only see the average power being drawn, so they will not trip until the actual measured current flowing for more than a few seconds is greater than their rating. (nb. a digital ammeter may be confused due to the rapid switching of the power by the triac)
3. Triacs are rated for a certain number of amps current flow - similar to a wire or fuse. If you exceed the current level that they are designed to handle, for a long enough time, they will overheat and fail. Usually the dimmer manufacturer uses triacs rated much higher than the dimmer rating to allow some fudge factor (often a 8 A or 10A triac is used on a 600W dimmer).
So you probably can get away with running lamps of greater wattage than the dimmer is rated, as long as you never run them at high percentages. This is risky though, as it is easy to make mistakes... Triacs will permanently fail quickly if too much current is flowing through them.


----------



## TorontoAlchemy

Ok, well that sounds more reasonable for the electricity use/etc.

Also, Bill, regarding why I would use lights with total watts @ 100% exceeding the dimmer capacity...

Three factors contributed to that:

1. Limited throw angles and distance. 

We are in a converted downtown garage with 12' ceilings, and also vertical support beams spaced 15' apart. As you can imagine lighting the space is very challenging. It would be nice to have one 500w Altman 360 from a distance of 20-30 feet providing a nice spread, but in our case we need to use 2 or 3 lights from a short distance to accomplish the same thing.

2. Limited fixtures and especially dimmers

We stage shakespeare mostly (although there are other rental companies who come in) and given our small downtown black box we rely heavily on lighting to define scenes/location/distance/etc. But our fixtures were all acquired hodge-podge (mostly E-bay), and we've had a limited (ie inadequate) # of dimmers for most of our shows. So from the example above in #1 if I can put my two 500w Altmans on one dimmer (since I know that I'm not running them more than 40% 'cause they are so darn close to the actor) then I can save another dimmer for design/specials/etc. 

3. Limited manpower

I'm actually not a technician, but rather the AD of the company & director of the shows (10 Shakespeare production in 4 years). In the early days I had no technical manpower and so had to learn how to do everything myself. So I'm not surprised to hear that I've done things (on the fly, under deadlines) which others might find strange. I guess Necessity is the mother of both invention and also strange solutions.

Anyway, just a bit of context there. But I'm learning...(slowly)

Thx
S


----------



## bslproductions

Using a 1000w lamp on a D4DMX unit should be ok even at full. Its not a 600w dimmer. Its a 2400w max dimmer with a per channel capacity of 1100w. You can use 4 x 1000w lamps, just not all at once. The problems described are extremely odd for the units though. We sell an average of 4 units a month year round and hardly even see units come back for repair/replacement (less than 1 every other year). Its sounds like you may have gotten lemons on the last 2 though. It happens from time to time, even with the best manufacturer. If they are less than a year old, you are still in your warranty period. Contact your vendor and have them replaced.


----------



## church

unfortunately if you have connected a 1000W load to a 600W dimmer - even with it set to 50% you have probably blown the TRIAC and or breaker. This is because when the TRIAC attempts to turn on the instantaneous current that flows is related to the instantaneous sine wave voltage and the resistance of the lamp. What (excuse the pun) this means is that if the dimmer is set to 50% the the dimmer control circuit will turn the TRIAC on at the peak of the positive and negative halves of the cycles which corresponds to maximum current flow. Agreed for a short time. This current flow produces rapid heating within the TRIAC which will be greater than the device can withstand and result in a premature device failure. TRIACs often fail as a short circuit.

Also with breakers if you keep popping them they will actually begin to pop earlier just an issue with secondary breakers of the type found in these types of modules.

Note this is a different sitiation to where you have a number of 1.2kW dimmers loaded to 1kW where if they were all turned to 100% the total current draw exceeds the available supply so the user writes a plot that avoids "full-ups"


----------



## avkid

church said:


> Also with breakers if you keep popping them they will actually begin to pop earlier just an issue with secondary breakers of the type found in these types of modules.


Remember that breakers are a mechanical connection.
As with any mechanical connection they wear with repeated use and have a finite life span.


----------



## Benchtech

I feel your pain. I have just gone through 8 of these this week, replacing the surface mounted DMX chips. If they are out of warranty, the factory recommends replacing them as they are too labor intensive to fix econimically and you can believe them. They are unless you have a lot of patience and spare time. As far as channels that stay on, the triacs usually short because of lamp failure when the filament breaks and spins around from the heat of the arc, causing it to hit the support posts and shorting them out drawing a lot of current. Sometimes this happens so fast that fuses or breakers can't catch it, taking out the semiconductors. Channels that don't come on usually are bad fuses/breakers, bad chokes (broken leads from vibration of moving) or optoisolators. 
If you are going to take a hammer to them, drop me a note and I will gladly pay the freight and use them for spare parts, or if they are easily fixed, I'll let you know.
Benchtech


----------



## JJWOODS

Hi I'm new to this forum, I have several D4DMX-MD5 units that are in need of repair.
I would like to try and trouble shoot the triac's on these units however since Leviton can not provide me a schematic and I can't find any threads regarding this I was hoping someone on this forum might be able to provide some guidance? 

I'm not sure where the triac's are located on the board or what they look like? Can someone provide some assistance or direct me to a photo of a triac? If I use a mulitmeter will a continuity function tell me if the triac's are good or bad?

One of the dimmer packs channels 1 & 3 Power on 100% and have no functionality, I think the triac's might be bad on these channels? Does any one know if there is 1 triac per channel or do they work in series?

Also a few of the units have bad led screens the numbers and letters are scribbled does anyone know where I can purchase a replacement screen?

Thank you in advance for any assistance you can provide. I spoke with Leviton tech support today after playing phone tag for three days to my dissapointment the tech support provided no help and told me they may be able to repair the units for $105 each which is about the price that we can purchase them for.


----------



## JD

Although there are many threads on this forum about repairing/ changing tricas on Shoebox dimmers (The term for a stand alone dimmer with a power cord, usually 4 channels) I must caution you:

Unless you are a qualified service technician, we could get in trouble for offering advice that may result in personal injury. This is why people here shy away from giving repair advice.

That being said, you may want to glance at this old thread: http://www.controlbooth.com/forums/lighting-electrics/7369-elation-dp-dmx20l-popped.html


----------



## BillESC

FWIW, the D4DMX packs are assembled in Mexico with parts supplied by Leviton/NSI, not manufactured in China.


----------



## DimmerDotCom

TorontoAlchemy said:


> ...I was using a voltage meter to check one of the non-working dimmers. My voltage meter dutifully told me that there was a strong 110v coming out of the dimmer. "So why won't my light turn on!!!", I cursed and fumed at the dimmer. Eventually I realized that although there was a nice strong flow of volts, there were unfortunetly no amps coming out! Doh!



Always measure dimmers with a load applied. Triacs are basically diodes. As such voltage seeks to go across the highest resistance, in this case the open plug which has near infinite "air gap" resistance. Thus the AC on the input side of the triac go to the load side. EVEN IF THE DIMMER IS TOLD TO BE AT ZERO PERCENT. 

As for load current and dimming, here's an waveform of the current draw of an expression 3 console (uses a switching power supply which is more efficient than a linear power supply).


----------



## hemi392

JJWOODS said:


> Hi I'm new to this forum, I have several D4DMX-MD5 units that are in need of repair.
> I would like to try and trouble shoot the triac's on these units however since Leviton can not provide me a schematic and I can't find any threads regarding this I was hoping someone on this forum might be able to provide some guidance?
> 
> I'm not sure where the triac's are located on the board or what they look like? Can someone provide some assistance or direct me to a photo of a triac? If I use a mulitmeter will a continuity function tell me if the triac's are good or bad?
> 
> One of the dimmer packs channels 1 & 3 Power on 100% and have no functionality, I think the triac's might be bad on these channels? Does any one know if there is 1 triac per channel or do they work in series?
> 
> Also a few of the units have bad led screens the numbers and letters are scribbled does anyone know where I can purchase a replacement screen?
> 
> Thank you in advance for any assistance you can provide. I spoke with Leviton tech support today after playing phone tag for three days to my dissapointment the tech support provided no help and told me they may be able to repair the units for $105 each which is about the price that we can purchase them for.



There are 4 triacs, one for each channel. If you remove the cover they are mounted to a heat sink and the edge of the circuit board opposite the circuit breakers. They are common triacs available from any electronic parts supplier. They are type BTA 16 600B and cost about $1.50 each. Make sure you get the BTA version and NOT the BTB version. You can use a multimeter or continuity checker to check for shorts. The circuit board MUST be removed for repair. This is NOT for the faint of heart. The good news is that the triac legs are mounted to the circuit board in slots so unsoldering and resoldering is really easy. BTW, the on/off switch only controls the DMX circuitry, so a shorted triac will be full on as long as the dimmer is plugged in. Good luck.


----------



## JD

A little bit more about BTA vs BTB triacs. The BTA triacs are electrically isolated devices that can be mounted directly to the heat sink. The BTB triacs have their mounting tab attached to one of their main terminals. If you were to use the BTB, the unit would short out the second you plugged it in. (best case) In the worst case, if your ground was not connected correctly, the entire case would be at line voltage potential. 

As you can see, a simple part substitution can create a dangerous situation.


----------



## NeroCaesar

So I have read everything from the start and I have to ask.

In a perfect exact world Could you...

Plug 1000w into a 600w channel of the leviton packs and only bring it up to 50% with no problems (not that I'm trying to... well kinda... but I want to know the physics behind it)

or will it blow because it will draw the 1000w anyway
or will it not matter because the Triac is fluctuating so much that the actual power draw is not enough to blow 600w


I also ultimately ask because I have a EDI 96 dimmer rack where I converted some cards to nondims to run a bunch of leviton packs in the house. As I have been reading and tested if I have 4 units plugged in at about 20% each the pack it drawing about 2400w anyway. I am worried that if I have a bunch of Levi packs, a little more than enough to over draw the power to the EDI Rack, that I will blow something even if every light is at 20%

Does that make sense? 
The EDI rack has 3 legs of 200 amps as I have been told
If I have 32 Levi packs and 128 S4 units at 575w each that's 613 amps about
Not to mention any other lights on the rack


----------



## derekleffew

NeroCaesar said:


> ...Plug 1000w into a 600w channel of the leviton packs and only bring it up to 50% with no problems (not that I'm trying to... well kinda... but I want to know the physics behind it) ...


See the thread http://www.controlbooth.com/forums/...61-overloading-dimmer-without-blowing-up.html :

STEVETERRY said:


> ...The same line of thinking applies to the dimmer branch circuit as to the main feed. This is a matter of good practice, not NEC rules. Intentionally overloading a dimmer is not a "good practice" solution to the problem. If you don't mind a tripped breaker in the middle of a performance, or a failed dimmer due to overheating--have at it. But if you want to implement a robust system that will be reliable, find another solution. And there are many--smaller lamp wattages, less fixtures, more dimmers, etc. ...


Especially bad practice on a shoebox dimmer like the Leviton D4DMX which uses fuse s instead of circuit breaker s. 
EDIT: Incorrect statement; the D4DMX uses "Resettable circuit breakers in lieu of fuses." One would still have to traverse to the, likely inconveniently-located, satellite pack to reset a trip however.

As for the physics behind it, see http://www.controlbooth.com/forums/question-day/9903-dimmer-voltage-experiment.html and dimmer curve. At a DMX setting of 50%, voltage was 83%


NeroCaesar said:


> ... As I have been reading and tested, if I have 4 units plugged in at about 20% each, the pack is drawing about 2400w anyway. ...


Are you measuring the current with a true RMS responding ammeter?


----------



## JD

Some thoughts to clinch it:

When do these Triacs blow?

Top three reasons:
1) Lamp flash-over, which draws many times the running current.
2) Shorted cable, which draws many times the running current.
3) Cold lamp inrush, which draws many times the running current. 

See a pattern? Number three is the one that will get you if you overload the dimmer. To get to 20%, you still have to come off of that cold filament. By some estimates, cold inrush can be ten times the running current of the lamp. It doesn't last long, but it's there. A properly designed 2400 watt dimmer will be designed with devices that can handle the cold inrush on a 2400 watt load. A 600 watt dimmer is not designed to handle the cold inrush of a 1000 watt load.

As has already been covered, Max current is achieved in the first 50% of the *linear* dimmer curve. 
At 50%, your triac is actually switching on at the peak of the ac waveform! Other *non-linear* curves achieve this at even lower settings. Even the cold inrush current bringing the lamp to 5% idle is rather amazing to watch on the scope.


----------



## NeroCaesar

Hmm I'm testing with a $24 homedepot AMWatt appliance load tester I figure its only taking out the average. (plug in the dimmer to the amp meter and then plug amp meter into the wall)

Thanks JD That filled in some missing parts in my logic


I dont think I'm asking the question right though...

I have the same amount of units with or without the Levi Packs and with the EDI MX System rack I have never tripped anything before. I wanted the Levi Packs for individual control. The heart of the question is:

Has the EDI Rack only been drawing as much amps as needed and therefore not over loaded, and now if I have the Levi packs that Draw full amount every time a light comes on at 20% will my total amp draw be greatly increased during shows...

or has the EDI rack been pulling the full amount of amps when at 20% like the Levi packs do...

or do the Levi packs not actually Draw the full amount of amps and my meter has been deceived because its reading the average and everything is normal?


----------



## derekleffew

Your THP103 The Home Protectors | Product Details | Reliance Controls Corporation is giving erroneous results. Measuring current or voltage of thyristor dimmers is tricky; RMS, non-sinusoidal waveform, power factor, triplen harmonics, etc. Whether 20A load on the EDI dimmer, or 4 5A loads on the Leviton pack, at 100% your draw will be 20A (assuming 120V input and 120V lamps). At less than 100%, your draw will be less than 20A, but exactly how much is difficult to predict. Again, see the other thread where I measured voltage output vs. control input. Your dimmers (either of them) will be similar but not exactly the same. Also remember--the dimmers themselves don't draw power (in any significant amount anyway), it's the loads (lamps) connected that matter.

Oh, and there's a fatal flaw in your original question :

NeroCaesar said:


> In a perfect exact world Could you...
> Plug 1000w into a 600w channel of the leviton packs and only bring it up to 50% with no problems (not that I'm trying to... well kinda... but I want to know the physics behind it)


Although it was stated

bslproductions said:


> Using a 1000w lamp on a D4DMX unit should be ok even at full. Its not a 600w dimmer. Its a 2400w max dimmer with a per channel capacity of 1100w. You can use 4 x 1000w lamps, just not all at once. ...


most assume that any 4-channel satellite pack will be 4x600W dimmers. (Is there/has there ever been, a variant of the D4DMX that's only 4x600?) But there's that other issue: even if the pack contains 4x1200W dimmers, doesn't mean you can safely put one 1000W lamp on each channel AND run them all at full.

From D4DMX-MD5 > D4DMX > Satellite Dimmer Packs > Dimmers > Lighting Controls > Products from Leviton Electrical and Electronic Products :

> Item Description
> 4-Channel Programmable Dimmer Pack integrating stand-alone, 5-PIN DMX, & NSI Microplex, operates as 1, 2, or 4 channel with pre-programmed chases, 1200 Watts/Channel, *2400 Watts/Maximum*, *15 Amp Power Supply Cord*, 120V.


To me, 2400W Max and 15A supply cord appear contradictory, but maybe it's just me. And given the very likely Edison 5-15 connector, I'd be hesitant about putting 2400W or even 2000W on the pack. I've melted plenty (too many) of 5-15 plugs on 2000W Fresnels. 16.6>15, every day and twice on Sundays.


----------



## 65535

Since a dimmer works by chopping the incoming power you can expect to measure peak currents at full load, however the average power used is a fraction of that. Still furthermore the triac or SSR units in the dimmers will see that full current even if the average consumption is below the dimmer rating, it may well not blow a fuse or a breaker but it can do damage to the dimmer.

Because of this cheap non RMS meters will register peak current which will give you a power consumption of full load, even if you're using far less. 

Due to the filament resistance vs. temperature curve I could imagine seeing much higher peak currents at lower dimming levels.


----------



## JD

Ok, here is what is happening any why the readings are wrong- 
1) In the top image, the full ac waveform is passing
2) With the dimmer at 75% (liner) the bulk of the waveform is still passing, including the point of peak current draw.
3) Even at 50%, you are switching the triac on at the peak current draw of the waveform.
4) At 25%, you still have a pretty good current spike being drawn.

What is happening is the duration of the waveform is being changed. Most meters are only measuring the amplitude of the waveform, thus the bad readings.
Until you get below 50%, the amplitude does not start to decrease. 



(Picture credit goes to a quick google and to this website where I found the image: http://computerchristmas.com/christmas/link-how_to/HowToId-92/FullSize-true/LowLimit-10/StepId-12 )


derekleffew said:


> To me, 2400W Max and 15A supply cord appear contradictory, but maybe it's just me.



When you see something like that on the cut sheet, it makes me question everything written on the page!


----------



## NeroCaesar

Ok excellent, that's what I thought, I just needed a bit of confirmation.

And luckily (kind of but not really) we are a L5-20 twist lock house so at least the plug I put on there can handle the amps.

I won't be trying to over load any channels any time soon. I've used these boxes for almost a decade and know they blow up with a strong breeze. 

Thanks for the help and links,


----------



## pkooistra

I am wondering if someone can help me in my ignorance. We are trying to get a D4DMX dimmer working, but it always resets itself to 0 dim when the power is turned off. Is there a way to lock it so we can mount it some where and not have to worry about manually increasing the dim to 100 on the dimmer? I have looked around and read through the 4 page manual and can not seem to find an answer to this. Thanks for helping a newb at lighting.


----------



## derekleffew

The address reverts to 0 when power is cycled, or the intensity goes to 0%? Are you using a controller /console?


----------



## pkooistra

Intensity goes to 0. Simple 16 channel levitron controller, but it does not seem to act different if the controller is plugged in or not.


----------



## Lotos

pkooistra said:


> Intensity goes to 0. Simple 16 channel levitron controller, but it does not seem to act different if the controller is plugged in or not.



Yeah... These packs aren't designed to hold their level indefinitely... Especially not once power has been cycled.
(Ironically, derek's question was a blast from the past, as I've seen D4DMX's "forget" their DMX address quite frequently when power cycled... Seems to be a semi-common issue with packs I've run into, both in my venue and elsewhere... I much prefer my older NSI packs to the newer Leviton ones.)


----------



## Lightguy48

I stumbled across this thread looking for technical documentation on one of these dimmers because I bought it used and like many other folks it had several shorted channels.

I happen to own some really old NSI equipment and it is sad to see how they have 'cheapened' their product offering over the years. I have never been a big fan of triacs for dimmers. I always preferred a dual-scr design. Sure a triac is nothing more than two SCR's packaged into one case but if you look at the thermal capacity of a dual-scr design vs a triac the dual-scr design always wins out even with the same current rating. 

I have an NRD-8000 and an ND4600, both of them a virtually indestructible. Each individual SCR has a large heat sink per device, then you look at the D4DMX it has one single heat sink shared by 4 devices and then also relies on the heat to be distributed to the back mounting cover yet there is no heat sink grease to help conduct the heat to the rear panel.... very poor design indeed...

If there is only one good thing about the design it's that they still included chokes on each channel. I've seen really cheap Chinese crap with no filters at all or a single filter for all channels... those things put so much garbage on the line I've seen some of them actually generate enough noise to throw the gating/ramp signal into a tither within the dimmer pack itself.


----------



## JD

Lightguy48 said:


> I stumbled across this thread looking for technical documentation on one of these dimmers because I bought it used and like many other folks it had several shorted channels.
> 
> I happen to own some really old NSI equipment and it is sad to see how they have 'cheapened' their product offering over the years. I have never been a big fan of triacs for dimmers. I always preferred a dual-scr design. Sure a triac is nothing more than two SCR's packaged into one case but if you look at the thermal capacity of a dual-scr design vs a triac the dual-scr design always wins out even with the same current rating.
> 
> I have an NRD-8000 and an ND4600, both of them a virtually indestructible. Each individual SCR has a large heat sink per device, then you look at the D4DMX it has one single heat sink shared by 4 devices and then also relies on the heat to be distributed to the back mounting cover yet there is no heat sink grease to help conduct the heat to the rear panel.... very poor design indeed...
> 
> If there is only one good thing about the design it's that they still included chokes on each channel. I've seen really cheap Chinese crap with no filters at all or a single filter for all channels... those things put so much garbage on the line I've seen some of them actually generate enough noise to throw the gating/ramp signal into a tither within the dimmer pack itself.


Most modern commercial dimmers these days use SSRs (Solid State Relay) for the power end, as compared to discreet SCRs or Triacs. Basically, a monolithic device that contains the opto isolator, firing circuit, and thrysistor all in one part. At its heart, that thrysistor could be a triac or set of SCRs, but unless the part manufacturer tips his/her hat, we will never know 
Back to the "shoebox" NSI, as long as you have 25 amp triacs in there, they hold up pretty good. Shame they come with 15's. Modern triacs and SCRs are better at handling some of the real high current spikes the the old beasts, but I must admit, it was pretty hard to take down some of those old back-to-back SCR dimmers.


----------



## Floobydust

Kinda late for me to chime in to the Original Poster, but I've had some shoebox or treepack dimmers that had a problem with the DMX signal timing and did erratic things like the D4DMX unit; changing the Break time to at least 200 micro seconds seemed to solve the problems.

Doug Fleenor Designs has a unit and so does DMXKing.com that will re-time the DMX signal.

My two cents worth.


----------



## florentinian

I'm new to theatrical lighting (after a career in software and software-controlled hardware. A small playhouse here has been having long-term grief with their lighting and I 'volunteered' to see if I could help (I was tired of paying to watch 'strobelight' theater). The gear is 6-7 years old-- a Leviton MC-7016 controller and three D4DMX dimmer packs (bought new). Stage lights apparently have always flickered sporadically, plus the dimmers run hot, though the lighting loads are modest and well below Leviton's per-channel and unit recommendations. Some of the flicker was caused by worn/dirty crossfader sliders in the MC-7016. Cleaning them helped a little, but we live on the Pacific coast (where we clean sand from our gutters instead of leaves and salt air corrodes everything). So I replaced the two sliders and that helped some more. The remaining flicker was analog-noise related and switching from Microplex to DMX digital protocol resolved that. The lighting is now flicker-free.

My questions relate to the dimmer packs. On opening the D4DMX's for inspection/cleaning, I was pretty surprised to find the output AC receptacles were connected to the PCB using only the spring-loaded push-in rear connectors on the receptacles -- in fact the receptacles don't even have screw-down connectors except for the ground wire (ironically, the receptacles aren't made by Leviton either). That led me to look for the UL seal, only to realize there isn't one. On the hottest-running dimmer pack, three of the push-in receptacle connectors would pinwheel freely and when I pulled the neutral output leads from their lugs on the PCB, the lugs themselves came off instead of the connector -- the damn wires had gotten hot enough to semi-unsolder the lugs from the PCB! 

Needless to say, I'm not very impressed with these dimmer packs. They look like a fire waiting to happen, the triacs look like they were spec'ed for 220V operation and no one considered what that would mean in a 110V market like the US (where the current is doubled). I can replace the receptacles with commercial rear-screw units, resolder all the power lugs on the PCB, and upgrade the triacs with something beefier for probably less than $20 a unit (I work cheap). I'd prefer not to tell the theater owner he ought to deep-six these units. My question is: "What else does everybody know?", or, are there any other gotchas awaiting me with respect to these units. Any advice would be appreciated. I realize they're entry-level units and all, but damn, no UL certification? I didn't even think that was legal (or if legal, not very smart). My opinion of Leviton has dropped considerably.

Anyway, thanks in advance for any insights/warnings. I've already learned a lot from this forum, and want to thank its forum members for sharing their hard-gained knowledge.


----------



## gafftaper

Welcome to the Booth! I love the Oregon Coast. My family makes the Pilgrimage down from Seattle at least once a year. 

Yeah unfortunately, you have low grade dimmers and you get what you pay for. If you want to buy dimmers with no UL rating, they are readily available. Will they continue to work for long? Probably not. What you describe is not at all surprising to me. It sounds like you have the skills and brains to do your own rewiring and upgrading work on the dimmer packs which is great. But it's not the kind of thing we recommend around here because it's too easy to start a fire with a little mistake, especially when you are working with such low quality equipment. What should you do? Throw them away and spend a couple grand on some decent dimmers. Is that likely to happen? Yeah, of course not. So you do what you have to do to keep them going. 

The best advice I have is make sure a qualified electrician inspects anything you choose to do before you plug it in during show conditions... and start saving your money for a decent dimmer pack. 

(Moving this thread to the Lighting forum. The new member forum is really just for saying hello. You'll get more information in the lighting forum.)


----------



## len

I have a bunch of these and I have never experienced the heat issue. I will say that I only put 2 x 575 HPL loads on them at a time (at most). Part of your issue may be environmental, and nothing anyone can do about that. If they're that old, I'd say it's time to move on regardless of how good your experience with them has been. I've also used these a lot and they're pretty solid. http://www.leprecon.com/support/product/33

What about using a permanently installed dimmer rack? Considerably more expensive, but considerably more durable.


----------



## gafftaper

Leprecon is definitely a good moderately priced decent quality solution to consider if you are going to replace them. ETC and Strand make the best dimmers, but you pay a lot for that reliability and they too will struggle with that salt air. Or you can go with the cheap ones from Chauvet/Elation. They will be fine for a while and when they go out because of the salt water in the air, they are cheap enough to consider them disposable and buy new ones. I think I like that solution if you are thinking about replacement.


----------



## BobHealey

The Lepreon units are also sealed units, using the chassis as a heat sink instead of relying on air flow through. That might help keep the salt air away from the electronics inside.


----------



## gafftaper

Now the really important question. I haven't been down as far south as Florence in a few years. Has the Fred Meyer been swallowed by the Sand Dunes yet?


----------



## JD

Check around the forum a bit, thee are a couple of good threads covering the servicing of this and it's competitors from Elation and Chauvet. There is a 25 amp triac that subs just fine. Consider the packs to be 600 watts per channel with an 1800 watt pack limit and they should serve you well. They are low end dimmers and I have been down the road of changing out the connectors as well as eliminating the spade lugs as these are weak points. 

The Warning: The usual "Only by a qualified servicer" applies as I would not want anybody to be working on something that could cause a fire or death. If the packs are new, remember that working on them voids the warranty. If they have UL certification, modifying them causes them to no longer be certified.


----------



## florentinian

gafftaper said:


> Now the really important question. I haven't been down as far south as Florence in a few years. Has the Fred Meyer been swallowed by the Sand Dunes yet?


They have a "win-win" arrangement with a landscaping materials contractor next door. He regularly drives a front-end loader and dump truck across the street and into the back of the F/M lot to replenish his "sand" bin.


----------



## florentinian

JD said:


> Check around the forum a bit, thee are a couple of good threads covering the servicing of this and it's competitors from Elation and Chauvet. There is a 25 amp triac that subs just fine. Consider the packs to be 600 watts per channel with an 1800 watt pack limit and they should serve you well. They are low end dimmers and I have been down the road of changing out the connectors as well as eliminating the spade lugs as these are weak points.
> 
> The Warning: The usual "Only by a qualified servicer" applies as I would not want anybody to be working on something that could cause a fire or death. If the packs are new, remember that working on them voids the warranty. If they have UL certification, modifying them causes them to no longer be certified.



I've upgraded two of the three units to BTA24's from the original BTA16's and I'll do the third one shortly. Fried triacs on one pack was what got me involved in the first place; a 16A triac to chop up a 10A load at 110V is pretty optimistic, but about right if you're running a 5A load at 220V. I'm just about certain the heat is related to the crappy spring-tension connectors on the load receptacles. The packs are way out of warranty, they have no UL/CSA certification (if they did, I doubt I'd be having to work on any of this). As to "qualified servicer", well, I agree in theory. But who's qualified? Leviton seems to have gone down the same path as General Motors with their ignition keys. I do take your admonition very seriously though -- I only wish Leviton did. Frankly the D4DMX units look like their last design cycle was done by an MBA instead of an engineer.


----------



## florentinian

florentinian said:


> They have a "win-win" arrangement with a landscaping materials contractor next door. He regularly drives a front-end loader and dump truck across the street and into the back of the F/M lot to replenish his "sand" bin.



A trivial pursuit question: Did you know Frank Herbert got the inspiration for his Dune saga from the sands dunes here in Florence? There's a large collection of his research material on permanent display in our public library (The Frank Herbert Room).


----------



## gafftaper

florentinian said:


> They have a "win-win" arrangement with a landscaping materials contractor next door. He regularly drives a front-end loader and dump truck across the street and into the back of the F/M lot to replenish his "sand" bin.


Ha! That's awesome! Although it strikes me as odd that anyone in Florence would need to buy sand. 


florentinian said:


> A trivial pursuit question: Did you know Frank Herbert got the inspiration for his Dune saga from the sands dunes here in Florence? There's a large collection of his research material on permanent display in our public library (The Frank Herbert Room).


That's crazy! That I did not know.


----------



## techieman33

florentinian said:


> Frankly the D4DMX units look like their last design cycle was done by an MBA instead of an engineer.



Pretty much. Dimmers like these were designed for the low end DJ market. Now churches and theaters are using them and asking more from them then they were really meant to ever do.


----------



## Terry Simpson

Similar sort of issues. 5 years ago, I bought 4 of these leviton d4dmx-md3 For a Fitness Center project. We have 36 LEDs, but I use these as DMX-Relay switches for Blacklight (4' UV floros), and they have worked fine, with very little use (maybe 50 hours in 5 years). (I also recently bought 14 of the 5-wire DMX version for our Film School studio, where they will be used mostly on Tungsten fixtures). Anyway, we were having (suddenly) a bunch of issues with whole DMX runs crapping out (until you broke the daisy chain, when the light you were working on popped on), Anyway, in trouble shooting the whole system (I think a bad cable or 2, some Addresses had gotten changed by the cleaners dusting, and the panel Terminator had gotten pushed, and was double-terminating), AND I found out that the CHannel control on this one unit could NOT be changed, it only reads "CH00" (instead of CH01, CH02, or CH04, like the others show). It is not LOCKED. No combination of button pushing makes it change. The Program (P01) mode does not cycle through channels. Any ideas? Is it just fried? Anyone seen this before? Any help appreciated.


----------



## florentinian

My thoughts: (1) Disconnect all data cabling before trying to diagnose D4DMX configuration issues. (2) Make sure the "cleaners" didn't randomly reconfigure the unit to Microplex protocol. (3) Add dimmer packs one-at-a-time and verify correct operation before adding the next cable and dimmer pack. (4) Make sure you haven't inadvertently plugged a DMX cable into a Microplex port (not likely on at the 5-wire versions). I've done all of these dumb things myself, so please don't take offense at my suggestions.

The issues with the Up/Down push buttons not operating could indicate a failure on the control side of the printed circuit board, or it could simply be a mechanical issue (e.g., a corn-chip fragment has gotten under the case cover and is interfering with button operation). As a simple test of the latter, disconnect power and data, take the back off the case (9 screws), then loosen (but don't remove) the five screws that mount the PCB to the case. Wiggle the board a bit and use a can of compressed air to blow under the board (particularly around the buttons). Press all the buttons and verify they all "feel" the same. Then tighten everything up and replace the cover. That may do it. If not, unless you know a PCB repair technician, you've got a dead dimmer. 

Also, while the case is open, examine the condition of the wires going to the outlet receptacles (especially the neutral/white wires). If they show any sign of scorching/heat damage, I strongly suggest you consider replacing the cheesy spring-contact receptacles provided by Leviton with screw-down, back-wired receptacles from your local hardware store -- your fire insurance carrier will thank you.


----------



## Terry Simpson

1) Done, 2) DMX, and 3) benchtesting it. No diff. 
The insides looked very good, hardly even any dust after 5 years. Buttons were not the problem because they work perfectly for all other menues. Another clue: putting it into P01 (simple chase thru all channels) did NOT light any LED's or lights connected. 

FYI, my next step was to call NSI at 800-824-3005, work through the menuses to talk to Tech Support, the receptionist took some info, and said a Tech would call back within 24 hours. Got a call from Bill the next morning. He was great! Very friendly (said he was pleased to hear that these were even working after 5 years), after taking me thru menues and establishing that I was describing things correctly, he tried one reset: turn off, hold all 4 buttons while powering up (factory reset?). Anyway, it should have reset everything, including A001-instead it still showed A262. His diagnosis: hardware problem, needs fixing. $97 flatrate, plus ~$20-30 shipping to him (they pay for return and give 90-day guarantee), all standard--meaning 4-5 weeks turnaround. Expedited gets it fixed in a week for $30 more. My decision: Full Compass sells these for $145 now, with a 2-year guarantee. No Contest. We are truly in a throwaway society. Thank you all. Hope that helps others.


----------



## JD

Put it in your "turkey carcass" pile. Sooner or later you'll need to pick some parts off it.


----------

