Post a reply to the thread: Antique BDP Heat Pump--new tstat issue.
You may choose an icon for your message from this list
Please enter the name by which you would like to log-in and be known on this site.
Please enter a password for your user account. Note that passwords are case-sensitive.
Please enter a valid email address for yourself.
Will turn www.example.com into [URL]http://www.example.com[/URL].
"I'm thinking a heat pump thermostat that the reversing valve is energized in heating by hooking the "RR" relay up to the "B" terminal of the stat." I'm pretty sure that IS the way it is with the two Honeywell thermostats that I installed. But after thinking about it some more, I don't think I need to add a relay. Instead, I think I can simply remove the RR2 connections, that enabling Y when W is applied should never be necessary, since the thermostat is always going to enable Y when it enables W.
Originally Posted by georgelass If W closes RR, then RR2 gets closed, connecting R to Y which closes the compressor/OFM contactor, regardless of whether the tsat energizes Y. That appears to be NORMAL operation for this unit. Or am I reading this wrong? That is the way I read it. I'm thinking that W should never be energized unless Y is also energized, that if I want to make this thing work with a thermostat that has W always energized unless in cooling, then I need to add a relay, power its coil with Y, and run W across the normally open contacts so that W is energized to unit only if both W and Y are energized from the tstat? I have never had to do such a thing before--modify a unit, but does that sound like it would work? I'm thinking a heat pump thermostat that the reversing valve is energized in heating by hooking the "RR" relay up to the "B" terminal of the stat. .
Originally Posted by rundawg If you can get the mods to move this to the PRO forum, I'll post the wiring diagram. I won't post manuals or technical info in this "OPEN" forum. When the reversing valve (RR) is energized from "W", one of the two reversing valve relay contacts closes ("RR2" ), connecting "R" to "Y", to bring on the indoor fan. That relay contact could be stuck closed, powering the contractor? Sent you an email with the manual too. If W closes RR, then RR2 gets closed, connecting R to Y which closes the compressor/OFM contactor, regardless of whether the tsat energizes Y. That appears to be NORMAL operation for this unit. Or am I reading this wrong? I'm thinking that W should never be energized unless Y is also energized, that if I want to make this thing work with a thermostat that has W always energized unless in cooling, then I need to add a relay, power its coil with Y, and run W across the normally open contacts so that W is energized to unit only if both W and Y are energized from the tstat? I have never had to do such a thing before--modify a unit, but does that sound like it would work? Again, thank you, Rundawg.
Originally Posted by georgelass Package heat pump. BDP/Carrier Mod 542B030HP However, when I turned the thing to OFF, the contactor for the compressor & outdoor fan stayed on. It wasn't. I didn't spend much time on it before it started raining on me, but it appears the W terminal on the unit was energized. Y wasn't. And that seemed to energize the the contactor, judging from its removal de-energizing the contactor. So if anybody has a wiring diagram or can help, I would be extremely thankful. If you can get the mods to move this to the PRO forum, I'll post the wiring diagram. I won't post manuals or technical info in this "OPEN" forum. When the reversing valve (RR) is energized from "W", one of the two reversing valve relay contacts closes ("RR2" ), connecting "R" to "Y", to bring on the indoor fan. That relay contact could be stuck closed, powering the contractor? Sent you an email with the manual too.
Antique BDP Heat Pump--new tstat issue. Package heat pump. BDP/Carrier Product 542BU0030000PBAE (actually, first 0 is a greek phi, I think.) Mod 542B030HP serial 22/77/V/20227 I'm guessing it is a 1977, 35+ years old. It had an old mercury bulb tstat on it and new tenants simply wanted something modern and nice. They wanted me to install a Honeywell they bought. I did. Heating and cooling were fine. However, when I turned the thing to OFF, the contactor for the compressor & outdoor fan stayed on. I tried a good Honeywell off my van. Same behavior. Called Honeywell. They thought my contactor was merely stuck. It wasn't. I didn't spend much time on it before it started raining on me, but it appears the W terminal on the unit was energized. Y wasn't. And that seemed to energize the the contactor, judging from its removal de-energizing the contactor. I don't remember seeing an O or B on the unit's terminal strip, so I'm thinking W was the correct place for the reversing valve wire. Of course, I don't have the wiring diagram. In hindsight, I should have taken the wiring diagram to the dry and perused it there. But the rain was gaining energy! So if anybody has a wiring diagram or can help, I would be extremely thankful. Thank you.
Antique BDP Heat Pump--new tstat issue.
Forum Rules