Bev-Air BM23 Thermostat or Not

[3BadDays]

Hello All, new guy here .
Have been cruising around site for week or so and decided I need help.
Have (2) Bev Air Bm 23 S/N of the one I'm working on is 7902955 (photo)
Unit did not run, I saw the suspect black electrical tape on the condenser fan motor wires.(photo)
Pull the whole bottom tray down carefully and spliced in new wire.

Plugged unit in and condenser fans starts right up, compressor has nice little hum, and a little vibration. The inside evaporator fan is running. I put a thermometer inside and let it run, in about 1/2 hour temp was down to 10 deg F.
And there was some frost starting to form on the line circled in red in photo. Turned thermostat down ,which had no effect.
Finally pulled plug to get it to shut down. Plugged it back in 10 minutes later Evap fan came on but that was it.
After reading a bunch of posts on here , I figured I have a bad thermostat, went out this AM with the intentions of jumpering 2 thermostat wires together to bypass therm, but before i did I plugged unit it and it ran fine again.

Now I don't know what to do. Any suggestions would be greatly appreciated.
DSCN1427.JPGDSCN1419.JPGline freeze 2.jpg

[pvs6]

Only thing you can do is watch it's cycle times and confirm that they stay normal. Put a 5 gallon bucket of water inside and run it for a day then check the temp of the water. 38F. is considered mid range of beer temp settings so slowly tweak the T-stat till it holds the water steady at 38. If it can do that for 2 days without issue you're go to go. If not You will need a new T-stat in all likelihood.

[3BadDays]

pvs6 , Thanks for response.
My confusion is when unit was running , compressor and condenser never cycled on and off. Pulled plug to shut down then it would not restart. But the next day it ran fine.
Can you think of any reason waiting 24 hours would allow it to restart normally.
Thanks Again

[THE ICEMAN]

pvs6 , Thanks for response.
My confusion is when unit was running , compressor and condenser never cycled on and off. Pulled plug to shut down then it would not restart. But the next day it ran fine.
Can you think of any reason waiting 24 hours would allow it to restart normally.
Thanks Again

It looks like you possibly have an R12 unit judging from the metal data plate on the compressor.

I presume you were getting frost in the area you indicated while the unit was running? If you're getting frost in the area you indicated, you have a problem. That is the filter/drier, it should be warm to the touch while the unit is running. Frost on the drier indicates that you have a restriction in either the drier or the capillary tubing - most likely the drier. If you were getting frost after the unit shut down then it may not be a problem. If it was frosting while running you will need a low temp Tech to take a look at it & probably replace the drier. When the unit got down to 10 you likely had a sticking thermostat & if it does it once it'll do it again.


THE ICEMAN

[3BadDays]

ICEMAN,
Thanks for your input. Yes it is an R12 unit, from some info you gave another poster awhile back it appears as if compressor was built in 1978.
The parts sheet I got off of Bev Air web site says Thermostat is # 502-290B but the one in the unit is a Ranco and has P502-48 AB stamped on it plus A30-3260-00 then under that 7838 7
Any help on which thermostat I need would be appreciated.
I'm going to run again tomorrow and keep better notes on what is going on.

[THE ICEMAN]

If you can't find a Bev Air t-stat you can go with a Ranco A12-700. It might be a few more dollars but they work well & are a good match for a BM23. Amazon carries them.


THE ICEMAN

[3BadDays]

Iceman,
I found a A12-701 at a pretty nice price, will that work ? Also the capillary on current Tstat is probably 30" long or so, as you know it is inserted in a cooper tube attached to the front of the evap. The A12-700 and A12-701 say they have 84" capillary, what do i do with the other 54" of capillary ? Stupid ? I know , but I'm learning.
Thanks

[THE ICEMAN]

The A12-701 will work fine but the 700 has a slightly lower temperature range which would make it better for beer applications. As for the excess cap tube I usually take the handle of a screwdriver & coil the cap tube around it leaving just enough at the end to insert into the evaporator coil.


THE ICEMAN

[3BadDays]

Iceman,
Well I ran it again today for 3 hours , I did put a 5 gal bucket of water in it. After 3 hours inside box temp was at 10 Deg F, water bucket had thin coating of ice on top. The condenser fan did NOT cycle on or off at all during the 3 hours. Evap fan ran fine. This time NO frost on the filter/drier. Found a $30.00 Amazon gift card laying around from Christmas, so bought the A12-700. I'll post up details when I get it installed. Thanks for all your help.

[3BadDays]

Iceman,
Rec'd new Thermo and installed. Solved the problem. I have run it now for 4 days it cycles on /off about 3-4 times times per hour. When it cycles on it runs for about 1min 30 seconds to 1 min 40 seconds. It has kept a constant temp of 38 Degs F for 4 days. Happy camper here.
I appreciate all your professional guidance.
I got 2 of these units BM23's basically for free, I had to drive about 80 miles round trip to get them but that is my only cost so far.
The thermo I actually got for free, went on Amazon to order and they offered a $50.00 gift card if you signed up for a Amazon credit card. So I got Thermo and they still owe me $1.95.
The second unit is not quite as easy, I know it needs a thermo , and condenser fan motor likely $100.00 total. My question is , is there anyway to test compressor ? If I thought there was a reasonable chance I could get it running, I'd spend the $ 100.00 but just not sure it is worth it. Any suggestions ?

[THE ICEMAN]

A hundred bucks seems a bit much for those two parts... Shop around.

If all you are wanting to do is see if the compressor runs, you can just jumper the leads at the temp control. Don't run it too long without the condenser fan though.


THE ICEMAN

[3BadDays]

A hundred bucks seems a bit much for those two parts... Shop around.

If all you are wanting to do is see if the compressor runs, you can just jumper the leads at the temp control. Don't run it too long without the condenser fan though.


THE ICEMAN

Thanks Iceman,
I had a guy offer me $250.00 for both units so i sold them.
I found a nice 2008-2009 Model BM23 and bought it. But i do have a question. New unit runs great, but this one has original Bev-Air Temp Control , and it's off for 43 minutes and then runs for 26- or 27 minutes. Temps are right on the money. Should add temp control capillary is mounted on the back wall of cooler.. Do these run times seem normal ? When I installed the A12-700 you recommended on my other unit it ran perfectly as mentioned in post above. My next question is if cycle time on this unit is not normal , can you recommend a replacement ?
Thanks

[THE ICEMAN]

Yeah, Bev Air started putting those cap tubes on the back wall some years ago, they should have kept it in the evaporator IMO... The back wall method senses the air coming off the coil while a cap tube in the coil will sense the temp of the coil itself. The benefit there is that if the coil freezes up the one placed in the coil should sense this & allow for proper defrost when the one on the back wall would keep running trying to come down to temp.
The run times seems a bit long but as long as the unit holds temp & the evap coil stays free of ice buildup you should be fine. If you decide to change the control you could still use an A12-700 but you would need to insert the cap tube in the coil. If there is no tube on the coil to insert the cap tube into you can carefully fold the end of the cap tube into a large paper clip shape, 2 to 3 inch long & the insert that between the fins of the coil - roughly in the center of the coil.

THE ICEMAN

[3BadDays]

Yeah, Bev Air started putting those cap tubes on the back wall some years ago, they should have kept it in the evaporator IMO... The back wall method senses the air coming off the coil while a cap tube in the coil will sense the temp of the coil itself. The benefit there is that if the coil freezes up the one placed in the coil should sense this & allow for proper defrost when the one on the back wall would keep running trying to come down to temp.
The run times seems a bit long but as long as the unit holds temp & the evap coil stays free of ice buildup you should be fine. If you decide to change the control you could still use an A12-700 but you would need to insert the cap tube in the coil. If there is no tube on the coil to insert the cap tube into you can carefully fold the end of the cap tube into a large paper clip shape, 2 to 3 inch long & the insert that between the fins of the coil - roughly in the center of the coil.

THE ICEMAN

Iceman,
As always thanks for quick response.
The evap coil has a place for the tube but no tube there.
When I bend cap into paper clip shape and insert into coil do I need to anchor it somehow or just kinda of push it in between the fins ?
Does it actually need to be touching part of the evap coil ?
My intention is to make the paper clip shape insert it, and then gently bend the cap 90 degs towards tstat mounting location, Make Sense ?
And as per your hint the last time, use a screw driver handle to coil up the remaining excess of cap, tape it off and out of the way.
Thanks
3BD

[THE ICEMAN]

I presume you have decided to use an A12-700 & not the factory control - the factory control will not work properly if placed in the coil. As I mentioned, it senses the air temp while the A12-700 would sense the much colder coil temp.
Yes, you would insert the "paper clip" in between the fins, bending it would be fine. It does not necessarily need to be touching the coil tubing itself but does need to be surrounded by the fins.


THE ICEMAN