CB/SBM, you got me kinda confused here on this gaspak deal. If I were
hooking up a cool only pkg unit to a two wire stat, I would just hook Y
and G together at the unit if the blower relay seemed OK, otherwise just
hook up the motor to the contactor and not mess with the relay. On this
one, they pulled four wires and hooked them up correctly if I understood
correctly. If this unit's blower ran when it got a green signal, what
changed when it also got a yellow signal? The green should have still
been energized. I'm sure if I saw the unit, it would be obvious, but
somehow I can't visualise what you were saying the problem was. You got
me curious-- can you please elaborate. Thx Larry
I'm not SBM, but I think he said that the old stat sent power to Y and
G both during a call for cooling.
May I take this moment to publically thank my Lord and Saviour that I
am not CB/SBM. There are some blessings that are impossible to
describe in words.
Christopher A. Young
You can\'t shout down a troll.
Actually, for a fleeting moment, the idea to connect Y and G together hit
me, but the landlord said that he wanted the fan to run independent of the
compressor...and if I did that, then every time that they turned the stat to
ON, the comp would kick in.
Now, remember its an old gas pack so the unit has a fan limit switch in it.
Its not hooked up basically, since there is no gas to it. so you forget
about the low fan speed.
The LuxPro he had to hook up to it, did not energize Y AND G just Y. I could
have tied on to the relay...sure. But see above.
Instead of adding parts he didnt need, and since the unit was being used as
straight air.....and since it was a POS anyway...
Taped off the other two fan leads. Took the high speed lead, and spliced it
so that if the stat gets a G call, the relay closes and the fan runs.
IF the unit gets a Y call, the contactor closes and energizes the same wire,
only NOT through the relay.
From the fan:
Lead goes to the fan relay. At the fan relay, a female spade has now TWO
wires leading from it. One to the fan, one to the unit load side of the
contactor, opposite of course, the common lead to the fan.
CB/SBM, thanks for the reply, and I understand now. What I don't
understand though, is why a stat would only energize only Y and not G.
That would work with most newer furnaces-- those with a Y term on the
circuit board, but any other furnace, and most non v/s air handlers have
to have a green on a call for cooling. I do not recall ever seeing a
heat/cool stat that worked that way, but then again, I haven't seen or
messed with every stat on the market, so I dunno. Thanks again Larry
If it's really a 2 wire stat, why can't he test for the 'sticky'
contactor in the furnace? ie. Pull the thermostat off (having two
exposed wires). Short wires together - furnaces comes on. Release
wires - furnace shuts off. If the furnace doesn't shut off then your
sticky relay holds true. Or does this 2 wire stat do something else?
Dont know but heres how to find out.
W and RH are the right terminals for straight heat. If you take off
either one at the stat and the furnace dont shut off then the wires
are shorted together or there is a problem in the furnace. To narrow
it down go to the furnace and take off either R or W, if it shuts off
replace the stat wire and if not, call a tech.
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