AC burns transformer
 

My AC keeps burning transformers in the past 6-9 months. I had a
RiteTemp 8022 thermostat before, and it worked fine for AC, but burnt
transformer whenever switched to Heat. The primary of the transformer
was burned out everytime. The transformer is 220V input for the 24V
output.

Later I found I had wrong thermostat and also bad wiring to the
thermostat. I install a new expensive transformer (about $40 vs $10
for the regular one) with pop-up switch (sorry, I don't know the exact
name. It's kind of transformer with a reset switch giving certain
protection) and replaced the thermostat by RiteTemp 8010 with wiring
instruction from the RiteTemp support. Both AC and Heat worked well
for about 3 months. Now, the transformer is bad again. However, both
the primary and secondary seem fine, but the reset switch of the
transformer went bad.

The possible reasons I can think a
1) The tenent turn on/off the thermostat too often (This is for the
rent house).
2) The tenent set the temperature too low for Cool and too high for
Heat, so that the AC/Heat hard gets rest.
3) The AC/Heat unit is two old. It is about 10 years old.

Do you have any idea what is the problem?
How can I find the problem and correct it?

Following is the wiring for the RiteTemp 8010 as you
taught me:

(Left are terminals from AC unit, right are terminals on RiteTemp 8010)
R to RH with Jumper to RC
O to O
G to G
Y to Y with jumper to the W terminal
W to W2
B to C
Others are not used.

Thanks for help.

Scott

In article .com,
Scott wrote:
My AC keeps burning transformers in the past 6-9 months. I had a
RiteTemp 8022 thermostat before, and it worked fine for AC, but burnt
transformer whenever switched to Heat. The primary of the transformer
was burned out everytime. The transformer is 220V input for the 24V
output.

Are you SURE its a 220 v input transformer? All such transformers I
have seen have been 110 v input. Applying 220 to a 110 transformer
would burn it out in short order.

--
Rich Greenberg Marietta, GA, USA richgr atsign panix.com + 1 770 321 6507
Eastern time. N6LRT I speak for myself & my dogs only. VM'er since CP-67
Canines:Val, Red & Shasta (RIP),Red, husky Owner:Chinook-L
Atlanta Siberian Husky Rescue. www.panix.com/~richgr/ Asst Owner:Sibernet-L

"Scott" wrote in message
oups.com...
My AC keeps burning transformers in the past 6-9 months. I had a
RiteTemp 8022 thermostat before, and it worked fine for AC, but burnt
transformer whenever switched to Heat. The primary of the transformer
was burned out everytime. The transformer is 220V input for the 24V
output.

Later I found I had wrong thermostat and also bad wiring to the
thermostat. I install a new expensive transformer (about $40 vs $10
for the regular one) with pop-up switch (sorry, I don't know the exact
name. It's kind of transformer with a reset switch giving certain
protection) and replaced the thermostat by RiteTemp 8010 with wiring
instruction from the RiteTemp support. Both AC and Heat worked well
for about 3 months. Now, the transformer is bad again. However, both
the primary and secondary seem fine, but the reset switch of the
transformer went bad.

The possible reasons I can think a
1) The tenent turn on/off the thermostat too often (This is for the
rent house).
2) The tenent set the temperature too low for Cool and too high for
Heat, so that the AC/Heat hard gets rest.
3) The AC/Heat unit is two old. It is about 10 years old.

Do you have any idea what is the problem?
How can I find the problem and correct it?

Following is the wiring for the RiteTemp 8010 as you
taught me:

(Left are terminals from AC unit, right are terminals on RiteTemp 8010)
R to RH with Jumper to RC
O to O
G to G
Y to Y with jumper to the W terminal
W to W2
B to C
Others are not used.

Thanks for help.

Scott


This is Turtle.

I feel the problem is in the B to C as to the problem. I can't see it from here
or you have not told if it was a heat pump or other type system. All I know now
it it has a Rite Temp 8022 and some type heating and cooling system it is hooked
too.

TURTLE

I checked the transformer. Actually it has input of 120, 208, 240,
480. Output is 24V with 75VA. I used the 240 input. It cannot be
wrong because I measured the voltage many times.

What confused me is the AC/Heat worked for almost 3 months.

Thanks

The AC/Heat has a heat pump with emergency heat. RiteTemp 8022 cannot
control it. That is why I replaced it by RiteTemp 8010.

As the RiteTemp support suggested, I don't have to connect B to C. It
just make the Thermostat's battery last longer if connected.

Thanks

"Scott" wrote in message
oups.com...
The AC/Heat has a heat pump with emergency heat. RiteTemp 8022 cannot
control it. That is why I replaced it by RiteTemp 8010.

As the RiteTemp support suggested, I don't have to connect B to C. It
just make the Thermostat's battery last longer if connected.

Thanks


This is Turtle.

The first thing your going to have to do is give a brand name , model number ,
and weither it is a split system or a package unit all outside. Give this and
something can get started but till then very little can be done.

Also I have never heard of B from the condenser being connected to the C of a
Thermostat.

TURTLE