Power consumption of 1/10 HP motor.

[RFI-EMI-GUY]

Can anyone comment the power consumption of this motor? Is this at all
typical. The application is a 800 CFM attic fan.

"1.2.2 Motor: 1/10th HP, thermally protected shaded pole type, 1100 RPM,
3.4 AMPS." - used at 115 VAC - 391 VA

My concern is not with peak load, but typical consumption when running
in that application. By comparison I measured my 1/2 HP rated air
handler motor at 3.0 Amps 230 VAC. 690 VA

Given that this is 1/5 the motor as the one used in my airhandler I
would expect it to consume only about 138 VA or 1.2 A at 115 VAC.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[James Sweet]

Can anyone comment the power consumption of this motor? Is this at all
typical. The application is a 800 CFM attic fan.

"1.2.2 Motor: 1/10th HP, thermally protected shaded pole type, 1100
RPM, 3.4 AMPS." - used at 115 VAC - 391 VA

My concern is not with peak load, but typical consumption when running
in that application. By comparison I measured my 1/2 HP rated air
handler motor at 3.0 Amps 230 VAC. 690 VA

Given that this is 1/5 the motor as the one used in my airhandler I
would expect it to consume only about 138 VA or 1.2 A at 115 VAC.

You need to know the power factor in order to get a meaningful number
here, it may only be around 0.5. One of those $20 Kill A Watt devices is
perfectly adequate for measuring the true power consumption.

Shaded pole motors are not very efficient, you'll notice they tend to
run very hot. Still, without knowing the actual load or the power factor
you're flying blind and anything is just a guess, but it's easy to measure.

 

[RFI-EMI-GUY]

You need to know the power factor in order to get a meaningful number
here, it may only be around 0.5. One of those $20 Kill A Watt devices is
perfectly adequate for measuring the true power consumption.

Shaded pole motors are not very efficient, you'll notice they tend to
run very hot. Still, without knowing the actual load or the power factor
you're flying blind and anything is just a guess, but it's easy to measure.

True but I have neither the motor or a Kill A Watt meter on hand.



--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[RFI-EMI-GUY]

1/10 HP is only about 75W. Obviously, the power factor and most likely
the efficiency is going to be piss poor. How much did this thing cost?
My guess is that any price is too high for what you are getting.

Bill

The 3.4 amp specs are typical for attic exhaust fans. Should I assume
that the nameplate current draw is "locked rotor" value provided in case
someone decides to install 5 of these on one 15 amp circuit?

I am only interested in what the motor normally draws while running. If
two of these fans require nearly 800 watts to exhaust and cool my attic,
I am concerned. If its only 300 watts I am less concerned. Does anyone
have a ballpark on this?

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[James Sweet]

The 3.4 amp specs are typical for attic exhaust fans. Should I assume
that the nameplate current draw is "locked rotor" value provided in case
someone decides to install 5 of these on one 15 amp circuit?

I am only interested in what the motor normally draws while running. If
two of these fans require nearly 800 watts to exhaust and cool my attic,
I am concerned. If its only 300 watts I am less concerned. Does anyone
have a ballpark on this?

I would guess about 140W, but that's only a guess. The power factor if
uncorrected is probably only about 0.5, so the VA will be around double
what the wattage is, and the label is for worst case conditions. In the
real world, the fan is probably not pushing the motor to produce its max
rated horsepower.