Carrier Timer PN: HK25AZ070 ---- HELP!!!

[amish hvac]

I AM DESPERATE:
We had a compressor rebuilt for a customer about a month ago. 30+ year old Carrier condenser in an ancient building- I know, we recommended replacement but this was what the dollars allowed for. After getting the compressor rebuilt and putting it back in place, there is a Paragon mechanical timer on the compressor that went bad (PART# HK25AZ070). Took a timer off the unit next to it, put it in and the compressor took off and ran great. Went to Carrier, they gave us the replacement which is now a circuit board rather than a mechanical timer (PART #HK35AA009). Our tech was not able to figure out how to put it in, got some other techs' opinions, nothing. Went back to Carrier and tech support. They told him to do this and that. He did that and it fried the board. Went to them again and they said they don't know what to do now and will get back to us and we're calling them 2x/day to no avail. I've been calling every Carrier guy I can find to see if anyone knows about this timer and can just give me the old one. PLEASE, SOMEBODY HELP ME! MY CUSTOMER IS GOING TO KILL ME AND CARRIER!

[DeltaT]

As I remember, all this is is a mechanical anti-cycle timer for the older larger tonage Carrier systems. It had a clock motor in it that ran a lot of brass gears and contacts. It looks like a washing machine timer.

Just replace it with a electronic timer of most any type that will keep the compressor from short cycling. Some of these might have also tied in with compressor pressure controls and amp draw.

Typically, back then they were line voltage controls too so be sure and check that. So if you hooked up the new low voltage board to the line voltage signal, that will fry it right away.

Go by the application of the old control - not by the control itself and replicate the function of the control. So if the old control had anti-short cycle - replace it simply with something that will do the same. Make sure the compressor is protected by all the right pressure safety switches and amp draw or voltage protection and you should be OK.

[trimble]

That electronic replacement timer has the exact same terminal designations as the old mechanical timer (A A1 A2 B B1 B2 D D1 D2 M1 M2 E E1 E2). You connect the wires to the exact same terminals as was connected to the old one. He might have got some of the wires crossed. If that is the case, you will need to get a wiring diagram for that unit and double check the wiring. I've replaced many of those timers without any problems.

[hvac3901]

could you use one of those little ICM anti-recycle timers? i hav'nt had a problem with one of those suckers yet. although i was a bit apprehensive a few years ago about the quality.

[mastercool]

Traneman is right, the terminals are identical on the new timer.........I have also replaced a few of them with no problems. However the first one I did I had a problem with because there is a slight wiring change made, in that there is no motor to power on the electronic timer and because of this you simply eliminate one side of line going to that board, it's been a long time since I replaced one but I think that's right. It has to do with the fact that you are no longer running a motor to complete the timing function.

[trimble]

Originally posted by hvac3901
could you use one of those little ICM anti-recycle timers? i hav'nt had a problem with one of those suckers yet. although i was a bit apprehensive a few years ago about the quality.

You need to go back with the OEM timer from Carrier. This is a multifunction timer. It controls part winding start contactors, it bypasses the oil pressure switch at start up, and it bypasses the low pressure switch at start up. It also interlocks with holding and lock out relays. To try to make the little black timers work would be more trouble than it is worth.