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How about that model number ?

Originally Posted by beenthere

Wonder how a T991A would work. its a proportional control, 0 to 135 ohms.

It would need to be a PWM signal.

Wonder how a T991A would work. its a proportional control, 0 to 135 ohms.

Originally Posted by mark beiser

I'd switch the 24v control signal to the motor, switching the 240v will fry switches, possibly even the module.
Unplug one while it is running and you will see what I mean.

If it has a Genteq/Regal-Beloit motor on it, a creative electronics person could use a PWM signal to control the fan speed.
I'm not aware of any off the shelf control that us less creative people can buy though.

Well, unfortunately I'm not a creative electronics person. As a matter of fact, its not my strong suit at all. I'm beginning to think a board over the damn fan is going to be his only option

Originally Posted by BaldLoonie

An ECM is wired hot. Low voltage signal tells it to come on. I suppose you could put a fan cycle kit in the 240v always hot feed but the constant cycling could be hard on the motor or the module. I would have a chat with a York tech rep before risking it.

I'd switch the 24v control signal to the motor, switching the 240v will fry switches, possibly even the module.
Unplug one while it is running and you will see what I mean.

If it has a Genteq/Regal-Beloit motor on it, a creative electronics person could use a PWM signal to control the fan speed.
I'm not aware of any off the shelf control that us less creative people can buy though.

Get us the full model number for the unit and let rundawg post the wiring diagram. With that I am sure we can help with your problem.

There is ususally two 24v control signal wires like a x13 but only two speeds.

There should be unused low voltage leads to the ECM. Try looking into the wiring configuration when a reheat coil is used.
I have to go back and look, but I know there is a way to drop the speed with the inputs. Maybe two inputs are used and you cut one of them??
Again, I will have to dig up the manual I am thinking of to be sure.

Originally Posted by uniservice

Call York tech support. They 've always been very helpful to me. Used to be a guy there named Smed that was sharp as a tack. I'm sure he's since retired, and probably dead. Neat guy and was full of information.

I'm glad you've had good luck with them. I however, have not. They have been pretty much worthless every time I have called. I always end up calling a distributor tech rep and they are pretty solid.

Originally Posted by JWB

those cheap supco's are just that. I would use a refrigeration style "real" ranco style head pressure control. But in this case, the ecm motor is a concern.
Increasing the heat load outside may take some creativity, sounds like your guy/customer is pretty smart. Anyway you could arrange for him to partially block the condenser during low ambient times? Just a thought.......

What I need is a head pressure control that completely cuts voltage to the fan rather than try to modulate it. The customer has already started blocking the fan somewhat but I fear the motor will fail before long... Does anyone know of a kit that completely shuts the fan off?

Call York tech support. They 've always been very helpful to me. Used to be a guy there named Smed that was sharp as a tack. I'm sure he's since retired, and probably dead. Neat guy and was full of information.

those cheap supco's are just that. I would use a refrigeration style "real" ranco style head pressure control. But in this case, the ecm motor is a concern.
Increasing the heat load outside may take some creativity, sounds like your guy/customer is pretty smart. Anyway you could arrange for him to partially block the condenser during low ambient times? Just a thought.......

Originally Posted by terpfan_

A common fan cycle switch would work to control head pressure. Johnson sells a bunch of models compatiable with 410a. A hot gas bypass could also help problem with solenoid to close bypass in heating mode. A combination of both might help as well.

Does anyone know of a good model for a fan cycle switch? I have a feeling that if I ask the counter guys at Johnstone for a fan cycle kit they are going to look like deer in the headlights.

Why not use a relay to cycle the low voltage signal?

Originally Posted by BaldLoonie

An ECM is wired hot. Low voltage signal tells it to come on. I suppose you could put a fan cycle kit in the 240v always hot feed but the constant cycling could be hard on the motor or the module. I would have a chat with a York tech rep before risking it.

Thanks for the info, I will give them a call tomorrow. The guy should have went with a City Multi S for this application...

An ECM is wired hot. Low voltage signal tells it to come on. I suppose you could put a fan cycle kit in the 240v always hot feed but the constant cycling could be hard on the motor or the module. I would have a chat with a York tech rep before risking it.

It is an ECM. I tried to install an ICM low ambient control on another heat pump before and couldn't get it to work. I followed the directions and also called their tech support line but it wouldn't go. Would a cut in/out work on the ECM? I would imagine it would.

Probably is an ECM on a super SEER unit. A fan cycle kit probably could cycle the 240v constant supply but the module may not put up with that for long. If York says don't do it, they would know.

Yes, it is ECM.

Originally Posted by Rob_in_WV

Good question, I've seen some low ambient kits that specify they are for use on ball bearing motors only.

Yep the sleeve bearings will not draw oil from wicks if not turning fast enough.

Originally Posted by SBKold

That unit have a fancy motor on it? Not ecm is it?

Good question, I've seen some low ambient kits that specify they are for use on ball bearing motors only.