Throwing Breaker


  #1  
Old 08-18-02, 06:34 PM
rmartin2101
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Throwing Breaker

I have a Rheem Classic X, Model #RAHE-060JAS, mfg. date 6/92.
It started tripping the dual 30A breaker about a month ago. Got progressively worse, till it would trip several times a day. I set the temp at 80 and went on a 10 day vacation. Came back the house is hot, the inside fan is running, outside is not. Probably been running nonstop for days. After inspection of outside unit, the two wire cord from the inside thermostat that connects to the contactor had a bad connection. I turned off the breaker and I would just jiggle the wire going to the outside unit and could here the contactor going on and off. Great, this is going to be an easy fix I thought. The wire was just barley twisted together and wrapped with electrical tape! After this it started working better, but it would still trip the brkr about once a day. I saw some soot around the contactor plate under the spring. I took out the contactor plate, cleaned it and the two contactor points. It seems to work fine. I tested the contactor coil with a meter, it seems fine. I then replaced the dual 30A breaker in the breaker box. I took off the start capacitor. It has a resistor between the two poles. I unsoldered it and tested the cap. I have a digital meter so its kinda hard to test it. It would just barely get a reading then go to infinity. I don't know if I'm testing it right.

How do I know if the cap is bad? What else could be wrong? Could the on/off activitiy of the contactor have caused damage to something else?

Also as an aside what should the normal temperatures and the temp differential be on the intake and cold air be?

Any help is appreciated.

Rick
 
  #2  
Old 08-19-02, 03:35 AM
bigjohn
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Look on the same nameplate where you found the model # and see what the minimum ampacity rating and maximum fuse/breaker size are. Check the circuit breaker to see if it's rated for HACR service. A good capacitor will cause the needle of an analog meter to start to go towards 0 and then back towards infinity, so the capacitor is probably ok. Can you solder the resistor back on? How did you clean the points on the contactor? They contain a thin layer of silver and, once that's gone, they're worthless. You may want to just replace the contactor with a new one. Look on the contactor for a label that indicates its' inductive rating in amperage. Replace with at least that size or a little larger. Temperature differential between supply/return depends on a lot of factors but the range is usually 17 to 21 degrees.
 
  #3  
Old 08-19-02, 06:28 AM
rmartin2101
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Thanks for the response!!

The label says min. supply ckt ampacity 38/38 Amp
Max fuse or HACR ckt bkr size 60/60 Amp
Min fuse or HACR ckt bkr size 50/50 Amp

What size should the breaker be? Does the dual 30 Amp with a black wire and a white wire going into it, the correct size? The ckt brkr does not specifically say its rated for HVAC service.

I ground both the contactor plate and the points with a grinder until they were smooth. If I ground off the silver would they still work most of the time?

I soldered the resistor back on the cap before putting it back on.

Could the problem with the contactor have damaged the compressor in any way?

Rick
 
  #4  
Old 08-19-02, 09:02 AM
bigjohn
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The circuit breaker or fuses at the outdoor unit have to be at least 50 amps and the wire has to be sized to carry at least 38 amps. I usually prefer to put in the maximum fuse or c/b size and go up a little in size on the wire. So- you need to have at least a fused disconnect switch with 50 amp fuses or a 50 amp HACR circuit breaker. You need to use at least #8 stranded wire from the disconnect or breaker to the unit along with a #10 stranded ground wire. You need to run the wires inside a piece of Sealtite using Sealtite connectors on the ends. [Sealtite is a brand name- I think the nomenclature is like flexible outdoor metal conduit- just tell the guy at Home Depot you need Sealtite, they should know what it is- you'll need either 3/4" or 1"] If you decide to go with a fused disconnect switch, you'll find that you have to buy a 60 amp size switch and then put in 50 amp fuses. Be sure to buy DUAL ELEMENT/TIME DELAY FUSES. You also need to replace the contactor. With the silver gone from the contacts, there's a good chance that the contactor will weld closed which will take out the compressor. If the compressor is starting and running, it's probably ok. Now I know that everyone is going to ask, "If his circuit breaker and wire have been undersized all this time, how is it that the unit has been running?" Answer- beats me.
 
 

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