[medic-dan]

Coat the end of the wire and put under the screw.

[Missouri Bound]

Pick up an inexpensive clamp on ammeter... you can find one for about $10. Then after you re-apply the anti-oxidant and reconnect the wire, you can check the load on the circuit while running. That will tell you if things are in order. How tight were the connections when you changed the breaker? And next time there is a rain, shut off the main and open the HVAC box and see if it has any water in it. There probably would have been some evidence of mositure when you were looking around in the box if that was the case.

[KISS]

OK guys. My turn.

You mentioned rain. With rain you have power failures while the system is running.

If the system experiences a power failure when running, the surge current in the system can me extremely large. I've seen fuseholders self-destruct under these conditions. The AC is trying to start under high head pressure and draws lots of current trying to do so.

Manufacturer's don't put protection in the compressors where it should be, but rather in the new electronic thermostats. After an off cycle, the tstat usually will not let the AC turn back on again until 2-5 minutes has elapsed.

Replace the tstat with an electronic one or add an anti-short cycle relay to the AC.

[kutra]

Thank you everyone for your replies. So the general consensus from all is:

1. Get the antioxidant paste from Home Depot and apply it to the tip of A/C wires before screwing them in the NEW A/C circuit breaker.
2. Get a HVAC guy the next time the A/C circuit breaker trips because very clearly the problem is not with the circuit breaker AND beyond my troubleshooting realm.

What say?

[KISS]

1. True

2. If your thermostat is not digital and programmable, change it.
You'll get energy savings to boot.

[hvac1000]

Coat all exposed Aluminum conductors with the paste. Get the GB brand (Gardner Bender) if possible available at Home Depot. This paste is electrically conductive and also stops corrosion on aluminum conductors.

Cut sheet for OX-Gard Grease

http://www.gardnerbender.com/pdf/msd...DS_Ox-Gard.pdf

See last page on this pdf for picture

http://www.gardnerbender.com/pdf/pro...connectors.pdf

As far as the digital programable thermostat goes if you are not going to use the set back feature for get it.To many people buy these thermostats and never actually use them and if you have a heat pump system they are all but worthless for saving energy. But if not changing the thermostat do purchase a time delay relay (delay on the break type) and wire it into the low voltage circuit for the contactor in the outside unit. Simple to wire and the directions should come with the item.

[kutra]

Coat all exposed Aluminum conductors with the paste. Get the GB brand (Gardner Bender) if possible available at Home Depot. This paste is electrically conductive and also stops corrosion on aluminum conductors.

Cut sheet for OX-Gard Grease

http://www.gardnerbender.com/pdf/msd...DS_Ox-Gard.pdf

See last page on this pdf for picture

http://www.gardnerbender.com/pdf/pro...connectors.pdf

As far as the digital programable thermostat goes if you are not going to use the set back feature for get it.To many people buy these thermostats and never actually use them and if you have a heat pump system they are all but worthless for saving energy. But if not changing the thermostat do purchase a time delay relay (delay on the break type) and wire it into the low voltage circuit for the contactor in the outside unit. Simple to wire and the directions should come with the item.

Thanks, hvac1000 for your detailed reply.

I shall get the GB brand from HD.

I don't plan to change my thermostat since I have a programmable one. This exact Honeywell model [Model # RTH7600D]: 7-Day Programmable Touchscreen Thermostat - Honeywell Your Home Expert. Is there some setting here that you want me to change?

Regards,
K

[KISS]

Your thermostat incorporates a 5 minute delay. If the power off condition was very brief, then the delay may not work. I've designed quick responding reset circuits in the past, so I know. Most need at least 50-100 ms to work. My circuit was less than 10 mS.

[hvac1000]

Under special features in the below link it talks about a wait period which is the time delay function built into your thermostat. You can test this feature to see if it is working by turning on the A/C then turning it back off in a minute or two. Then turn it back on right away and see if the WAIT sign shown on the thermostat and the outside unit is not running. If you get the WAIT sign and the outside unit is not running then the thermostat is working as it should. More than likely your thermostat is working fine and the power off time mentioned by kiss is so short it will probably never happen in real life at your location. We monitor the power generation end at Duke Energy Utilitys at the university for cycles per second variation (CPS), Line Voltage Anomalies (LVA), and almost all other power factor corrections and containment items. We have never experiences a micro second reading so small according to my checking of our computer records this day.

I hope you get it all figured out.

BTW here is a manual that addresses the wait period. Se page 20, and 17.

http://customer.honeywell.com/techli.../69-2207ES.pdf

Whatever you do forget about using the automatic changeover feature on this thermostat. In most areas it will cost a lot more money on your utility bill for the use of that feature.