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Fan Came Off Outside Unit, Fixed, No 24VAC Power


Brad4321's Avatar
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09-08-12, 06:11 AM   #1 (permalink)  
Fan Came Off Outside Unit, Fixed, No 24VAC Power

I have a Trane heat pump, model numbers and specs listed below. I heard a horrendous crash a week ago and it took me a while to realize what had happened (and the unit was trying to still run the entire time). The set-screw on the fan came loose and the fan dropped on the fan motor spindle smashing into one of the lines coming from the compressor. It dented the line but did not break it or leak any freon. I reinstalled the fan on the motor, hopefully a bit better than the factory did.

Pulling the electrical panel off, the contactor and one leg of the 220v main power was melted. I replaced the power wire and have installed a new contactor (and capacitor for good measure). The old contactor was still working and had continuity in the proper places, but best to replace.

With the system back together, I have no 24vac going to the contactor. If I manually push in the contactor, the compressor and fan motor fire, but they will not do it automatically.

I have been doing a lot of reading on this forum and others (I am sadly too broke to call a repairman) and I have read that if the fan stops spinning it can pop the high pressure switch. Looking at the wiring diagrams, the high and low pressure switches control the 24vac control side circuit.

I can't figure out how to reset the high pressure switch (I don't see a button on either switch in the outdoor unit, pictures below), or for sure which switch is the high pressure switch. However, with the unit turned off (but breakers on), one switch is very hot, guesstimating around 120 degrees, and you can't hold your hand on it for long. I have placed an arrow pointing to it in the pictures below. I do not know if this is good or bad, but I am suspecting bad.

I can somewhat read a wiring diagram and I have a bit of electrical knowledge, but I am not sure where to go from here. All help is very appreciated. I have a DMM and can take any measurements or whatever is needed. Some of the pictures are a bit blurry, didn't notice that until now. I can type out the information if needed.

Indoor unit data tag


Outdoor unit data tag


Outdoor unit wiring diagrams




Outdoor unit electrical panel (with new contactor/capacitor installed)


Previously burnt contactor


Outdoor unit with arrow to hot sensor



 
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09-09-12, 11:17 AM   #2 (permalink)  
Do you have 24VAC between Y & C outside with a cooling demand present?

 
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09-19-12, 03:50 PM   #3 (permalink)  
hi pressure switch

the valve that you have an arrow pointing to is actually a reversing valve and that is normal for it to be warm when it is energized. This is also a indication that you do have 24 volts to your unit. the problem is that you are not getting 24 volts to the coil of your contactor which could be a few things.... first off your unit probably has a time delay of about 5 mins and secondly the hi pressure switch will probably have 2 yellow wires going to it. in fact in your picture i can see the switch itself just cant see what color the wires are. it is located on small line and has a little copper line with a little plastic switch on end of it. you can trace those wires out and then check for continuity. if you have continuity then the switch is closed and that is not your problem. hope this helps.

 
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09-19-12, 04:50 PM   #4 (permalink)  
I will check for 24v to Y a C this weekend. Thanks for the info Onedonnie, I will look into that as well. I haven't forgot about this problem (how could I!), just been real busy the past couple weeks. I will post an update soon.

 
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09-20-12, 05:07 AM   #5 (permalink)  
Just as Houston said. Check your y to c circuit. If this circuit is open then you have a problem with one of the safety's as long as ur unit is calling for demand. The safety's on your particular unit are probably high pressure switch, low pressure switch, thermal overload on compressor, etc. being that your fan stopped it will most likely be that either the high pressure switch did not reset or the thermal overload on compressor did not reset.

 
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09-23-12, 01:57 PM   #6 (permalink)  
You are correct, the high pressure switch does have two yellow wires. I traced them and they have no continuity. I jumped around the switch and the unit kicked on like it should. However, when the compressor kicked off, I noticed a hiss. The fan did puncture a hole in the outside coil that I didn't see at first.

It seems that I am looking at replacing the entire outside unit since my research has shown that the cost difference from replacing the entire unit vs just the coil is fairly minimal. This brings up a question for all of you. I have tried researching this online, but haven't got a good, solid answer.

What needs to be done to convert this r22 system to R410A, or more specifically, can this be done keeping my current inside unit? I know that R410A runs at a higher pressure, but I have read that the inside coil can sometimes be reused. The entire system was replaced in 2008 and I don't want to touch the inside unit. If it is possible to convert to R410A for a reasonable price I prefer to do that now due to the diminishing supplies and increasing cost of r22. What do you all think before I start calling around?

 
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09-24-12, 07:08 AM   #7 (permalink)  
First off.... Why not repair what u have? U can repair that leak without changing entire coil. Secondly u will need to replace inside unit as well if you decide to go with r410a. You can flush lines with nitrogen, but I generally use rx11 which is a cleaner. Like I said though. If it were mine considering the unit isn't that old I'd find leak... If its in coil just cut away fins and make repairs as needed. Just my personal opinion.

 
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09-25-12, 08:15 AM   #8 (permalink)  
I have had two places come out and look at it now and both said they can't fix the leak and needed to replace the coil. I am getting estimates from every place around and we will see what the others say. I am just trying to think and plan ahead, but I have no interest in replacing the inside unit. If I do find a company that can fix the leak, I will go that route, but it isn't looking too likely.

 
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09-26-12, 06:29 AM   #9 (permalink)  
Well even if you can't find someone to repair the coil, then you always have the option of buying a nitrogen charged unit which is actually a r22 unit however it's not factory charged. It's a shame that no one is willing to make repairs anymore. I guess greed has gotten the best of most people. It's easier to change the unit then make the repairs I suppose. Anyhow. Good luck.

 
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