Heat Pumps and Electric Heating - Carrier Pkg Heat Pump Model 50QQ-60

Hey folks - I salvaged a working Carrier Pkg Heat Pump system Model 50QQ-60 with the 10kw Aux Heater from a place nearby that was going to be torn down. What a beast to move at 433 lbs! Anyway the problem that I am having is that the IFM (blower) is running all the time even when I have the tstat set to the OFF position and Fan control set to AUTO. This is not a new problem but one that existed before I moved the unit. Cools great, heats great but the blower runs constantly. Ideas?

One other thing I noticed as I completed the install is that the documents specify that this unit must use a specific tstat and sub-base. The tstat matches the docs (HH07AT171) but the sub-base does not. The docs call for a HH93AZ188 sub-base and the one I have is a HH93AZ173A. It would also be cool to know what the heat anticipator should be set at and lastly if I did install a new (more modern) tstat - what would you recommend?

Thanks for your time and your help!

Take G off the tstat if the blower stops then its the tstat . If it dont then is the fan relay or control board in the unit.

Morning!

Removed the G wire from the tstat and the blower keeps on running. Looks like the blower-relay is a normally-closed switch so it'll take a 24 volt call from the logic board (hangs under the relay) to pull the switch open and stop the fan I assume some seconds after the tstat requirement is met for either heating or cooling. (I think that's correct - lol)

So, I think I'll kill the power and go out and check the wiring to first be sure that I don't have an OPEN somewhere on the control side of the relay. Then I am thinking that I'll start it all back up and check for voltage on the control side of the fan relay and see where that leads me.

Wish me luck and Thanks again!

Been out checking the wiring... First no broken wires... Then as I trace the fan relay and delay board wiring, I discover that a single wire from the delay board is connected to C on the defrost board rather than R as indicated on the schematic. It could be that C provides the 24 volts to the delay board but I need to fire up the system and probe C to find out. If C does not provide 24 volts to the delay board it would appear that the darn thing is wired wrong. I'll let ya'll know what I find!

Thanks!

Ok an update... First the delay-board connection that I spoke about earlier is correctly connected to R and not C as I had mistakenly observed.

I pulled the fan-relay with the delay-board attached to inspect and test. The relay itself is fine - I removed the delay-board and connected my trusty VOM into the load side of the relay and provided 24 volts and a ground to the line side and CLICK. I had first thought that it was a normally CLOSED relay but it isn't.

The delay-board itself accepts 3 connections: 24 volt feed from R, tstat sense from G and ground via the contactor. So, the only control-input for the delay-board is the tstat via G.

It would appear that my delay-board is shorted, providing a continuous ground for the fan-relay. G dosen't make any difference connected or not and there is no other input so the delay-board is commanding the fan-relay ON all the time.

Now the big question is where can I purchase a delay-board? The local Carrier Dealer won't sell me one of course.

Delay-Board - Honeywell # 201282F with a large 9244 inked on the board next to the number.

Thanks for listening!

Check and see if you can buy at Johnstone supply they will have them in the ICM controls that match what you have.

Hey thanks for the tips.

I did find an OEM replacement part on the web but it turns out that we have a Johnstone Supply just up the street from where I live so I'm going to check there first.

I'll let ya know how it turns out and thanks again!

Hey Ed,

My local Johnstone Supply did not stock the relay that I needed but I found it on the web (exact replacement) and received it in two days time. I'm a happy guy, popped the relay with delay-board into the old unit and all is well!

Thanks again for taking the time to read my rambling posts and for providing great tips for doping-out the problem!

Regards from North Carolina!