IPS Dimmer issue

[Jwebb]

I ran into an issue last year where I had an IPS dimmer cutting out after being on for a few seconds (10 maybe). The dimmer was under a 2fer'd load of 1k watts. I swapped the 2fer, etc. No luck, same issue. Now if I took a unit out no problem. Other dimmers in the same rig seem to have no problem with the load.

Today I ran into the same problem though more widespread, I have the same situation with four dimmers (2 in one 6pack, the others are separate). Should I assume a bad relay? I have some spares I can swap out if need be. The manual is of no help and I searched but didn't find a similar thread. Thanks in advance for any assistance.

 

[microstar]

I realize you are talking about 2400 watt dimmers, but I have had problems with two 575 watt lamps on one 1200 watt dimmer, depending on if they were 115 volt or 120 volt lamps. The head-end processor on a DS1206 dimmer strip has a hidden menu that allows setting the maximum output voltage for all the dimmers in the strip to either 115 or 120 volts for a control voltage of 100%.

If the dimmers are set for 120 volts and 115 volt lamps are used, a dimmer with two lamps will shut down. If you reset the max voltage to 115, everything works fine. Of course your lamp life would be greatly reduced if you operated the dimmers with 120 volts max and used 115 volt lamps anyway. But you are not that close to dimmer capacity with 2000 watts on a 2400 watt dimmer so not sure this is the issue.

IPS dimmers do not used conventional SSR's; they use IGBT transistors as the power devices which would be quite a bit harder to replace (if you can even find them for the older model IPS dimmers).

Depending on the IPS model, you may or may not have a fan in the pack. Lack of ventilation could cause a shutdown, or dust/dirt blocking any convection cooling vents.

 

[Jwebb]

I was incorrect, I do have the 1.2k packs. Oddly a number of the instruments this is happening with are 6"fres which generally have 500w lamps but I am new to the facility and the stock is a bit of mix and match. I will check tomorrow and see if a couple of 750w lamps got into the system. Thanks for the heads up on the voltage setting. Is that an internal change?

 

[microstar]

No, this is set thru the display menu on the processor module. This is for the DS1206 dimmer strip with the L C R buttons. This sets max output for all six dimmers; they cannot be set individually. Press the L button until PLA appears in the display window. Then press and hold the C button until Hxyz appears. Press L button until F120 or F115 appears. Press R button to alternate between F120 and F115 selection. Press L to exit or allow display to time out.

 

[Jwebb]

Issue resolved with a slight amount of embarrassment involved. It was not a voltage setting issue, but rather a fairly simple wattage issue. As stated, I have the 1.2k model of IPS dimmers. To this point I thought my 6" fresnels have been lamped with 500w BTL's and for the most part that is correct, but it turns out a handful of 1k lamps has found it's way into the rig. One of the reasons I didn't think it was a wattage issue was that a couple of the pairs in question were fresnels, while one was a pair of Shakespeares, which in this house are lamped with 575w GLC's. Well after checking the voltage with no luck I popped open the units, found the 1k lamps in the fresnels and swapped them with the desired result. I checked the ellips and it turns out one unit in the pair had a 1k FEL (the only FEL in the house... none in inventory). Just a reminder to myself to always check the simplest possible solution first.

 

[microstar]

Thanks for reporting back. The dimmers were just protecting themselves from the humans.
Glad you resolved it!

 

[Jwebb]

Or at least this human. This is the beginning of my second year in this job and I am finding some interesting practices as a result of many TD/Designers over many years. One such issue is the variety of lamps in inventory. We have more than a dozen types of lamps but only four or five types of units. One goal for this year will be to due a proper lamp inventory and maybe put up the ones we will not need/use for trade. I did run across a couple of 400w black lights which could be fun for Halloween.