One thing our installer told us to do when he was giving us the preliminary training on the
system, was take the
CEM module out and dust off the board every once in a while. He pointed out a little IC on there that measures the airflow/temperature; he said if it gets too dusty, it will set off airflow alarms. I'd say get that
CEM module out of there and dust it off **carefully**. Also, when you pull out your
CEM, make sure that nobody is going to be bothered by the lights being off...everything in that
dimmer rack will immediately be shut off when you remove the
CEM. Even the fan and blue beacon light go off when you yank it...it's pretty weird standing there with your usually humming away
dimmer rack dead as a doornail.
When you remove the dimmers to clean them, be sure to shut off the breakers before you yank them. It's OK to yank dimmers from a hot rack, but just don't stick your
hand in there, as you will get a deadly 208V zap. If you're doing the whole rack, I'd recommend shutting the whole
system down first.
Clean out your air filters as well, they just pop right out of the inside of the rack door. Also a few more things to remember, every empty slot must have an
AFM (Air Flow Module) installed to seal up the hole. Without it air will seek the path of least resistance, which would be the hole. It would probably be a good idea to vacuum out your fan as well, but be sure you turn off
power before you go tooling around in the rack without dimmers installed. Keep the door closed when you're not working on the rack, or the filters in the door won't do you any good. Check for any air leaks around conduits and onther openings, and if you find any, seal them up. Our rack was sealed in various places by that expanding spray foam stuff. Does your rack's fan vent into the room, or does it go into a duct? Be sure the duct isn't blocked if one is installed. Also make sure something wasn't placed on top of the fan. Our old
Electro-Controls dimmer cabinet was infamous for burning up when the fans were blocked. It almost burned the place down twice when some idiot put stuff in the
electric room in front of the vents.
Is that 90ºF or ºC? 90ºF shouldn't be a problem, but 90ºC is definately too hot. I know my dimmers, D20 modules in an SR48 rack, or at least their
SCR heat sinks, don't get hot to the touch even when dimming 2250 watts all day on our
cyc light circuits.
Hope it all comes out OK.
ETC is famous for their good support, so if you can't get it fixed, and it was installed or approved by an
ETC certified rep, then you shouldn't have any problems getting
ETC to give you some advice.