2-Stage Temp Controller

[242447]

I got a Question about a 2-Stage Johnson controls-Penn Model# A28AA-36 2 SPDT 40/90 F. The Senser bulb is mounted in the return air duct If I set the temp at 65F on the controller. How does this temp. controller work Close the contact on raise opens on low temp so what will the temp be when it shuts off and what temp will it starts the unit up? Because I set the temp for 65 and I got 68 return temp coming back and it not starting if I hold the bulb with my hand and warm it up it start.

[supertek65]

I got a Question about a 2-Stage Johnson controls-Penn Model# A28AA-36 2 SPDT 40/90 F. The Senser bulb is mounted in the return air duct If I set the temp at 65F on the controller. How does this temp. controller work Close the contact on raise opens on low temp so what will the temp be when it shuts off and what temp will it starts the unit up? Because I set the temp for 65 and I got 68 return temp coming back and it not starting if I hold the bulb with my hand and warm it up it start.

it can work either way, it depends how you wire it!
there are common, normally open and normally closed connections inside the controller.

[supertek65]

it says spdt above, that would be a one stage controller?
unless the 2 in front of it means there are two single pole double throw contacts?

[jogas]

FWIW,
A remote bulb thermostat's differential can be additive or subtractive depending on the brand or model.
jogas

[Airmechanical]

read and follow the directions, if you dont have them, get them!

you will have to set temps and differentials for both stages

and as stated they can be wired and/or controlled with a n.o. or a n.c. circuit


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