Original message
| botree
 |  "low amperage reading while running"
, posted Mon 21 Jan 12:41:  
The squirrel cage blower I am using has an Emerson motor at 1/4hp 8.2A 115V 1050rpm. When it starts I see a jump to about 6 amps and then it settles down to almost nothing. On a digital meter set for 10A I see 0.01 and 0.00. The air is moving at a rate of around 8-9 miles per hour (wind speed indicator) which doesn't tell me anything except the it is moving air.
Is this low level of amps the motor is drawing telling me something I should know but don't and will it cause any damage to the motor running like this.
Thanks...Bo
hot or cold
[this message was edited by botree on Mon 21 Jan 22:29] |
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| static
| "Re(1):low amperage reading while running" , posted Mon 21 Jan 22:47
How are you getting that amp draw? On the common wire?
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| | botree
| "Re(2):low amperage reading while running" , posted Mon 21 Jan 23:11
Have the meter connected on the hot side to a "hi speed" wire and back thru the motor out to common.
hot or cold
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| | static
| "Re(3):low amperage reading while running" , posted Mon 21 Jan 23:53
They this. Remove the common wire from whatever terminal you have it landed to. Connect one probe of your Amprobe to this wire. Connect the other probe to wherever you had Common hooked to. Now you're ready to see some amperage.
Oh yes, have a look at this link. No it's not porn, it's about motors. Ought to be right up your alley.
Link: (It's a pdf.) Fasco Fastfacts
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| | botree
| "Re(4):low amperage reading while running" , posted Tue 22 Jan 20:50:
One thing I didn't mention is that while the blower was on the floor in my shop I slid a piece of lexan plastic over the opening a little at a time and I could hear the motor load up. Still no reading on the meter.
Static, the only thing I can come up with is that I am doing something wrong but I'll be D--n if I can tell what it is. I did what you suggested. Connected one side of the meter to the common from the motor. Connected the other side to the common from the outlet (lamp cord with on/off switch in line). I still see the same thing. Tried it on another motor, second squirrel cage blower, got the same thing. THEN I tried it on my shop vac. Same thing no amperage on the meter. Tried another meter. same thing. Both of those are digital. I have two analog meters but one is too small to have a 10A connection. The other showed a slight tic on start up but that meter had to be set for 0-250 range so you won't see much until the amps ramp up, which they still did not. I have tested hundreds if not thousands of pieces of equipment with BellSouth when I was working. I know what I am doing but I can't get a thing out of the meters.
Will try to see if I can take my meters to a guy a couple of miles from me and try them there. He will see what is going on.
Thanks anyway...this is beyond me.
hot or cold
[this message was edited by botree on Tue 22 Jan 21:20] |
| | static
| "Re(5):low amperage reading while running" , posted Tue 22 Jan 22:45
Strange indeed. Good luck.
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| | dwcaveney
| "Re(6):low amperage reading while running" , posted Tue 5 Feb 21:02:
The motor capacitor blew the fuse in your meter? Remember the amperage in the neutral and the hot will be the same. Do you have an induction clamp for your meter? If so, remember you have to separate the black and the white as the AC signal will cancel induction. Are you sure you have a line serial connection with the meter on either the hot or the neutral only and the other half of the circuit closed? The motor won't draw much once it reaches design RPM. Set the meter for ohms and test the motor. Remember E=IR, so I=E/R. AMPS=120VAC/RESISTANCE thru the motor. Don't worry about voltage drop (ie 100 volts could damage the motor)in that case the amp draw would be higher. If that doesn't work or you're not satisfied ......fire the mechanic.
[this message was edited by dwcaveney on Sat 9 Feb 00:48] |
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