Better to run this new motor on med or lo speed?

Questions about repairs and parts for Nordyne furnaces, air conditioners and heat pumps for manufactured homes including Intertherm, Mac and Miller brands. Click here for Nordyne parts.

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justplumducky
Posts: 48
Joined: Mon May 31, 2010 12:32 pm

Fri Feb 21, 2014 5:50 pm

Nordyne Model # MGHA-056ABFC-02

Standing pilot furnace with new (today) 1/3 HP, 1075 RPM, 3-speed motor. Old motor was possibly the original motor: 1/3 HP, 1100 RPM, 4-speed motor. Don't know what speed blower was running on.

Better to run this new motor on med or lo speed?


DaleM
Posts: 385
Joined: Wed Apr 07, 2010 10:07 am

Sat Feb 22, 2014 9:00 am

How big is the home and do you have a split system air conditioner? Is the blower used for air conditioning as well as for heating?

justplumducky
Posts: 48
Joined: Mon May 31, 2010 12:32 pm

Sat Feb 22, 2014 9:40 am

It's a 14 x 70 and is a split system, using same blower for cooling. 3-speed motor with a speed selection terminal block (easy speed changes) in the control panel mounted on front of the blower housing. Not a Presidential model however, with the Auto/On & Heat/Cool rocker switches on this control box.

I could change the speed to low for now, then change it to high for cooling later, if that is what you recommend.

DaleM
Posts: 385
Joined: Wed Apr 07, 2010 10:07 am

Sat Feb 22, 2014 11:27 pm

I would go with medium for heat and high for the air conditioning. There should be wiring there for you to be able to set medium for heat speed and high for air conditioning speed.

justplumducky
Posts: 48
Joined: Mon May 31, 2010 12:32 pm

Sat Feb 22, 2014 11:33 pm

DaleM wrote:I would go with medium for heat and high for the air conditioning. There should be wiring there for you to be able to set medium for heat speed and high for air conditioning speed.
Ok Dale, thx much. Please also tell me how you arrived at choosing Med speed for heat in this instance, as I will have other similar decisions to make in the future.


DaleM
Posts: 385
Joined: Wed Apr 07, 2010 10:07 am

Sun Feb 23, 2014 8:54 pm

Been a mobile/manufactured home service guy for over 30 years, 21 my own business. Furnaces usually use low speed with no A-coil to push the air through. When air conditioning is added we usually have to bump the heat speed up to medium so there is plenty of air flow throughout the home.

justplumducky
Posts: 48
Joined: Mon May 31, 2010 12:32 pm

Sun Feb 23, 2014 9:08 pm

DaleM wrote:Been a mobile/manufactured home service guy for over 30 years, 21 my own business. Furnaces usually use low speed with no A-coil to push the air through. When air conditioning is added we usually have to bump the heat speed up to medium so there is plenty of air flow throughout the home.
That really helps, thx so much.

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