Hello Community,

I’m hoping someone will be able to help me with this. Here we go. We have an American Standards Allegiance 14 Air Conditioner. Model No.: 2A7A4060B1000AA, 208/230 volts, PH 1, 60 Hz, 34.0 A, Compressor Motor 25 RLA @208/230V, O.D. Motor 2.80 FLA @200/230V.

It started having intermittent trouble. Sometimes we’d turn on the AC at the thermostat and could hear the inside fan start up, but it would only circulate room temperature air. I noticed that the outside unit – the compressor and fan – was not turning on. At first, I could turn the thermostat off and then back on again and the outside unit would kick on, and we’d have cool air. However, the threat remained that the unit would not kick back on once the thermostat stopped the unit at the desired temperature and attempted to start it back up. Eventually, the outside unit stopped coming on at all. This was at the end of the summer last year. It appears that finally, the AC unit (outside) will not come on at all. Whatever was going out must have finally gone out.

I did some testing already. I tested the thermostat to make sure it was supplying the necessary 24 volts consistently, and it is at the thermostat. I even jumped it to make sure that we didn’t have a bad thermostat, and still no joy. The outside unit would not kick on even with voltage coming from the hot-wired thermostat. I opened up the electronic section and discovered that the relay switch was not closing and making contact. I tested the voltage there, and it was not the 24 volts it should be. However, there seems to be a safety design in that the coil on the relay is not wired directly from the house but rather indirectly off of other components inside the unit. At first, this seemed to point to a bad thermostat except that I had bypassed the thermostat and directly connected the wiring to supply the voltage. This meant it had to be something else. I decided to manually compress the relay switch and supply power. Once I did this, I noticed that the compressor kicked on, but the blower fan did not (I did this with the power off and turned the power on after making sure the relay was pressed). I immediately terminated power and pulled the fuses to the AC unit so as not to burn out the compressor.

This seems to suggest a problem with the fan. Upon visual inspection, I did not notice any bulging capacitors. There are two. It appears that one is for the compressor and the other for the fan. They are connected to what appears to be a hard start relay of some kind.

At this point, I’m not sure if I have a bad starter cap, a bad hard start relay switch, or a bad fan motor or something in the fan assembly such as the switchboard or whatever it is that controls the fan motor. I have not taken it apart to check any of that yet.

I was looking around for replacement parts. However, it seems hard to find replacement parts for this unit.

The capacitor that I think is for the fan is the following:
21A101147P03
135-162 MFD
330 VAC
50/60 Hz
T-Max 65 degrees C

The other capacitor that I think is for the compressor is the following:
27L322
80 MFD
50/60 Hz
GE Capacitor

The start capacitor relay
3arr22j24n4
I think this belongs to the RLY02711 (I am not positive), but I mainly seem to be able to find the RLY01869 online.

The fan motor:
5SME39HL with the addition of HY71 in big letters.
I can find 5SME39HL motors but they usually do not end with HY71.

It appears to me that somewhere in this range of parts is the culprit assuming there is no problem with wiring. I have yet to check these things. However, before I do, I wanted to get an idea of the price of replacement parts. After a lot of checking around online, I found it hard to find many of the parts that I need. Some are labeled obsolete. Others seem to have similar parts, but I do not know what is safe to use or not. I’m not worried about the capacitors as I have been able to find suitable replacements for them. The fan motor seems to be another story.

My question is what parts would be safe to use as a replacement for these parts if they should turn out to be the culprit? For example, I can find 5SME39HL motors, but I can’t find HY71 exactly. I have found HY62 and HY73 for example. If I needed to buy a replacement fan motor, would one of these work with the existing circuitry? Does the HY71 part of the model number even matter when looking for a replacement fan motor? Is the 5SME39HL part of the model number the only part to worry about (ex. 5SME39HL HY62 versus 5SME39HL HY71 versus 5SME39HL HY73, etc.)? Would I have to replace anything else in order to make it work? What about the start capacitor relay? I don’t know exactly which one to get. The only meaningful number I was able to pull off of it was 3arr22j24n4. Google seems to lead to the above mentioned start capacitor relays, but again, I don’t know which ones I can actually use.

I’m a little out of my depth on this. If I could find the exact same parts, I could make the changes pretty easily. But when it comes to using different parts (even if only slightly), I don’t know enough to know how safe that would be with the other existing components or what other components would need to be changed to accommodate the new component. Another thing I read or saw somewhere was that it may not be the fan motor. Instead, it may be the board that controls the fan motor. There’s information on testing the control module as well as the motor using a tool that I do not have (TECMate). Any help would be appreciated. Can I safely use a 5SME39HL motor with something other than HY71 on the end? Can I replace the 3arr22j24n4 with the RLY02711 or the RLY01869? Will the “new” (or used since new seems hard to find for some of these parts) motor already have a control module in it? Thanks in advance.

 

Double check the MFD on the fan cap. Those numbers don't seem to be right.

 

You may find a capacitor in a different place for the fan. The two you mentioned are the wrong value. You are looking for a 5 thru 50 mfd capacitor.

 

Your variable speed condenser fan motor will not have an external capacitor.

Manually pushing in the contactor will not supply the control voltage to variable speed motors, so the fact that it didn't run isn't proof of a problem.

Can you post a picture of the wiring diagram?

 

I was looking at the specs for that 5 ton unit and it never mentioned the variable speed fan.

 

I Googled the motor number that the OP could find...

https://www.google.com/search?q=5SME...g&ved=0CCUQsAQ


Page 30 has a variable speed motor.
http://site.mypointnow.com/documents...specs2A7A4.pdf



Kinda looks like an ECM X13 since it doesn't have a board to control 2 to 17 volts..

 

Thanks for the help everyone.

@Houston204
I found some schematics inside the unit. I took pictures and scans. The paper I found is old, but the scans are reasonably legible. I'll try to get them uploaded tomorrow. I'm trying to figure out why the fan motor will not start and why the relay coil will not cause the relay to close and complete the circuit. I know the voltage across the coil is not enough to magnetize it, but I have to wonder if the fan motor not coming on is affecting the ability to magnetize the relay. The voltage at the thermostat is correct, but not at the unit outside. I would have to check again, but I think the start capacitor relay and/or caps are wired up to the coil or something like that. It does not appear to be wired directly from the house thermostat. It would seem reasonable since it would be bad for the compressor to start running if the fan motor was not working properly, but I am not sure since this seems so different from the units I find elsewhere (at least to me). Also, thanks for the info about the fan motor and relay. I did not know that.

@skaggsje & @PJmax
I double checked, and those are the correct ratings. According to the schematics I found, the start capacitor should be the CPT00091, and it is 135-155 MFD. The capacitor in there now is not the CPT00091, but its specs are similar with a slightly wider MFD range (135-162). The other cap is a run capacitor which for this unit is supposed to be 80 MFD. When I get a chance to post the schematics I found, you’ll see these are the parts listed with those ratings.

Thanks everyone who has chimed in so far. Hopefully you guys can help me get this sorted.

 

Here is a link to the pictures I have of the specs. The easiest thing to do is click on ‘View Album’ in the upper right hand corner, select the individual pic, and click on zoom to see more detail.

AC Slideshow by Tumbleweeds | Photobucket

 

Just FYI, the problem is sorted now. I should have followed my first mind and looked more closely at the wiring. The way the unit appears to be wired from the inside threw me off because it didn’t look proper. I knew something was off because I wasn’t getting the voltage across the relay coil that I expected, but the wiring inside appeared so different that I wasn’t sure if it was due to the low voltage wiring. Tracing it back didn’t appear to lead where I thought it would. Anyway, it turned out to be some bad low voltage wire at the unit. Once it was rewired, everything kicked in. Thanks to those that tried to help.