Cad cell eye

bentley

Can anyone tell me what the eye itself is made up of? We recently moved a Miller trailer furnace into place and at start up there was a lot of racket..the noise quit after ten seconds or so...but I notice that the eye is missing. Could the eye have jostled loose and fallen into the motor fin and now just lying on the bottom? Will it do any harm? Please and thank you in advance for your help. The furnace was on it back during transport

bentley

The furnace was on its back during transport...

ratio

Cad stands for cadmium. Not very healthy stuff to leave laying around I believe.

I wouldn't leave anything laying around inside a motor. Peek inside & see if you can see anything. You need to find out if it fell out, or never got installed & you're looking for something else.

Jamie Hall

Cad cell... is made of a thin layer of cadmium sulfide, which changed resistance from high in the dark to low in visible light. Not great stuff, but not all that bad unless you choose to munch on it.

That said... if it is really missing or misplaced, the burner on your furnace shouldn't fire at all, or if it does, it should shut itself off in anywhere from 15 to 30 seconds or so, depending on the control. If the furnace runs, noisy or not, either the cad cell is there and mounted properly and your looking at something else, or if it really isn't there, you have a very dangerous defective control...

bentley

Jamie Hall ...The furnace will run only about 30 to 45 seconds..and the eye is indeed missing..I have the replacement info for it and can get one.

EBEBRATT-Ed

@bentley

I would make sure to remove the old cad cell if caught in the burner housing. Also check that the motor turn freely and that the blower wheel isn't damaged.

Make SURE to have the power off when doing this.

You should have someone do a combustion test now as the furnace has been relocated & check all safety controls

Jamie Hall

To which I would add -- this is not what I would call a do it yourself job, unless you happen to be handy with oil burners and precision test instruments...