CARRIER AIR CONDITIONER/HEAT PUMP PROBLEM
WOULD NOT RESPOND TO THERMOSTAT. UNIT IS AT
LAKE HOUSE WHERE WE DO HAVE BAD STORMS. IN
CHECKING, INSIDE PART OF UNIT HAD BURNED UP THE
TRANSFORMER

what I have always been told is if your 24 volt side burns out check the high volt side if the hi volt side burns out check the low volt side.

A quick way if the primary side is burningout due to a problem with the low volt side:
1 MArk all the thermostat wires at the indoor unit
2 Disconnect them at the indoor unit.
3 Check main line voltage before proceeding (A 208 volt is not considered 220V and 240v Is not considered 208V> In these circumstances the voltage may have changed with the power company replacing a transformer and now you need to change the main power input lines at your control transformer for the correct operating voltage). If okj then proceed:

4 If you have an amp meter attach it to one of the lines going to the transformer.
5 Apply main power and listen for hum, note if smell starts again and if so problem has to be in board or main incoming voltage too high or too low. Amp draw should be less than 3 amps.
6 If your to this point and still havent found any trouble in the above as of yet, Connect the wire marked "C" together. Then just touch the thermostat wires one at a time to the places where they go on the indoor unit and watch the amp meter. If you donmt see the meter jump the circut is probably ok but leave them disconnected until you touch all of them to the correct place or wire. Here is a possible problem I ahve seen a thermostat wireing problem if the wires are stripped too far and a "whisker" of the wire sticks out and allowes one of the other wires to cross short out. In this case just cut off the excess wire or bend it over out of the way asnd continue with the test. You can always cut it off later after the tests. If you see the meter jump up and stay up and /or blowes the fuse the wire that you used and it blew is where to consentrate.
7 No wiring problem found means that you could have a relay or contactor not pulling in properly.
and this will cause the amp draw to go way over the transformers power out put or VA rating.
8 Inspect the thermostat wiring for the "whisker" I mentioned above.
9 If you have done this to the end of the thermostat wires and your main incomming voltage is correctly wired in on the transformer andf your relays and contactors are pulling in evenly and not delaying excessively your problem should be fixed.

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