Hi. I didn’t know where else to ask, so here it is. I need to replace a motor that came from a range hood. The motor is 3.3″ motor, 2 speed. I think I found a similar motor, but I am lost on hp label and number of speeds.
The old motor is labelled 1/20 hp, and it is 2 speed – it has black, white and red lines coming out of it. In the searching for a new motor, I found that multiple speed motors are now labelled with multiple horsepowers, i.e., 1/20-1/30.
Is this just old practice changing to new practice that is more specific? Can I replace old motor labelled 1/20 hp with new motor that is 1/20 – 1/30 (spec’d as 2 speed)?
Both motors are 115v, around 2 amps, single phase, 60 hz. The switch is off-high-low dial switch. As far as I know, the switch does not control the speed.
The motor manufacturer is not in business now. The motor comes out of old Chambers range hood. I found a.o. smith motor that I think I can work with.
Thank you in advance.
Replies
Sure
If it fits physically, and you can get the wiring to work, the lower horsepower will not draw as much current. So, the wring will be safe. The new motor may, or may not move as much air.
Probably "truth in labeling"
Probably "truth in labeling" -- the motor produces a lower HP at low speed.
But for a low-power fan like this, anything that fits and is even approximately the right HP will be fine. 1/20 HP would be under 40 watts at 100% efficiency, but such low-power motors tend to be low efficiency so 2 amps is probably about right. The wires feeding the fan can handle a minimum of 15A, so there should be no problem with overloading the wiring or such.
The switch controls the speed, only in the sense that it selects which winding is powered. White is the common lead and the red and black will be low speed or high speed depending on which way the SPDT switch is flipped.
Thank you all for the replies. I plan to buy the ao smith motor as well as have the old motor refurbished by changing the sleeve bearing and the lines. The old motor is still working, just not sure when it will give out (approaching 60 years, although used in the range hood). Old motor will be the factory size back up.
To summarize, the original motor, although label says 1/20 hp only, does have 2 windings to make it 2 speed motor? The new motor is Shaded Pole motor, double shaft, 3.3" diam., and is labelled 1/20-1/30 2 speeds, if that makes any difference.
Again thanks in advance.
Yes there are 2 windings, hence 3 wires (tied common to the white).
With new bushings, that will probably run another 60 years. You really should replace these oilite bushings tho. They are factory impregnated and when that goes, anytthing else is a temporary fix. Flushing with a solvent like mineral spirit and reoiling with 20w electric motor oil will usually get you a year or so.
Ace hardware does carry a small selection of them and any bearing store will have just about any size you need.
Thank you and all others for the answers. I am going to take the motor to a repair shop for the sleeve and wire changes. I will ask about changing the oillite bushings.