Control/Dimming Sensor Dimmer temp strawpoll

[danTt]

Hello, World

Curious to those of you who have/maintain sensor dimmers (bonus points for sinewave)--What temperature do your racks like to "idle" at (read from the CEM) when they are not being used/fan off? Seeing ~100F on mine, which feels high for clean racks in a room that is 66 degrees.. but maybe it's more normal than I'd think?

 

[Brentgi]

I have smartpacks that idle at about 75℉. I know this is not the equipment that you were asking about but I thought I'd share.

 

[Mac Hosehead]

I believe you need the fan spinning for a period before you will get an accurate ambient temperature reading. I don't think a reading with the fan off tells you much.

 

[danTt]

I believe you need the fan spinning for a period before you will get an accurate ambient temperature reading. I don't think a reading with the fan off tells you much.

Well, it would tell me where the rack temperature sits when there is nothing but the CEM on in the rack. Being 25-30° above room temp feels high to me, curious if thats consistent with others experiences though

 

[sk8rsdad]

What it's telling you is what the electronics of the CEM are reporting, which may not be the same thing as the actual temperature. A thermometer would be a better choice than a survey to confirm if you are getting an accurate reading.

I would guess that most of the rack is at ambient room temperature. Some of the electronics on the CEM will be above ambient and depending on their proximity the sensor may be giving a false reading. ETC Support would be able to provide a definitive answer.

 

[Mac Hosehead]

The operation of the temperature sensor in a CEM has been described to me as being a little heater that needs air flowing over it to get an accurate temperature reading.

 

[FMEng]

The operation of the temperature sensor in a CEM has been described to me as being a little heater that needs air flowing over it to get an accurate temperature reading.

In which case it is really an air flow sensor, not a temperature sensor. An air flow sensor should read high when the fans are off.

Certain broadcast transmitters offer a reading of exhaust differential temperature. They measure intake temp and exhaust temp, and the reading is the difference. It is far more meaningful than just exhaust temp.

 

[JD]

Keep in mind that even with the board settings at 0, the dimmers are actually operating at trim level (~2%) so the SSRs are passing power and generating heat.