Leviton D4DMX dimmer nightmares

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
 
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.
 
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!
 
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
 
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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
 
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?
 
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
 
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).
 
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.
 
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.
 
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 :-/
 
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
 
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
 
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.....
 
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
 
Electrician gave incomplete information about dimmers

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.
 
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
 
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.
 
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"
 
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.
 

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