New motor wiring issue

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Darth vader

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Hey guys just signed up. I've read questions on the forum for a while but now I have a question. Today I wired three identical brand new baldor motors 10 hp, 230/460v, 22/11 amps. They are 9 wire and all wired for 480v. They all have a small squirrel cage on the end of the shaft for air flow movement Inside down draft tables. Two of the three motors are pulling 22 amps @ 480v? The third is normal pulling 10 amps @ 480v. I have never seen this before? The motors are drawing the 230v amp rating even though they are wired for 480v. They all are wired on a 20 amp twist lock plug because the tables are moveable so after the tenth time of checking the wiring I wired up the third one and that one is pulling the normal 10 amps. Any thoughts or help would be appreciated. Yes the motors are wired for 480v. 4+7, 5+8, 6+9, 1 to L1, 2 to L2, 3 to L3. Is it a factory wiring problem with one of the windings wired wrong
 
Mechanics were I worked would say "its always an electrical problem" when it seldom was.
(The overloads tripped, because the pump was plugged)
The amperage a motor draws is determined by the load. What are the three motors driving, is it the same load?
 
As I stated they all have a small squirrel cage on each of them. So there is really no load they are just moving air. All three are new start ups two are pulling the 230v nameplate Amos and the third is normal. It has to be some kind of miss wired winding of some sort. I have wired a hundred motors and I've never came across this issue before
 
Baldor does not test their motors at 480v, they only test at 240.

I had a 50hp motor that was hoisted on to the roof of a headworks plant that when we started the motor for the first time, it blew the fuses. After the crane left with the old motor.
We metered out each winding according to the Baldor wiring drawing for that motor.
We found the two leads were mis-marked and when connected to 240 volts it ran.
We changed the tags on the leads and reconnected and it ran fine, except it probably had a couple years of its life shortened.

If Baldor tested at both voltages, they would have found the mis-marking.
 
Here hear,

tom baker said:
Mechanics were I worked would say "its always an electrical problem" when it seldom was.
(The overloads tripped, because the pump was plugged)
The amperage a motor draws is determined by the load. What are the three motors driving, is it the same load?
Click to expand...

Darth vader
As I stated they all have a small squirrel cage on each of them. So there is really no load they are just moving air. All three are new start ups two are pulling the 230v nameplate Amos and the third is normal. It has to be some kind of miss wired winding of some sort. I have wired a hundred motors and I've never came across this issue before
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Click to expand...

No load? Just Air? Actually they have twice the load that they are rated for...It is a mechanical problem. Like Tom said.

It's the rotation. Check the one that is pulling properly, its the way they need to spin.

Downdraft tables normally use a backward inclined blower, not a squirrel cage blower. May seem counter intuitive to the uninitiated. But backward incline is used for higher static pressure than a squirrel cage.

MTW Ω
 
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Tim also makes a point I was hoping to hear also. If rotation is correct like I believe it is because it is exhausting correctly and not blowing out of the table I wondered if a winding wire was mis labeled. I believe I am more at the point of searching what time has said. I will check everything again against the one working correctly too and I will let everyone know
 
A high pressure blower, backward incline. Will normally blow in the same direction either way. Its when it rotates like a squirrel cage wheel should, it moves near twice the volume of air at a lower pressure.

When the leads are factory mislabeled, it's usually 6&9.

MTW Ω
 
My guess:
You have the two motors that are pulling high amps strapped for 240V, then by giving them 480V it sends them into immediate saturation, amps go really high.
 
MTW said:
A high pressure blower, backward incline. Will normally blow in the same direction either way. Its when it rotates like a squirrel cage wheel should, it moves near twice the volume of air at a lower pressure.

When the leads are factory mislabeled, it's usually 6&9.

MTW Ω
Click to expand...
And when connecting to 480 volt supply those two leads tie together and you wouldn't ever know they are labeled wrong. It would cause problems if motor is configured for and connected to 240 volts.

Jraef said:
My guess:
You have the two motors that are pulling high amps strapped for 240V, then by giving them 480V it sends them into immediate saturation, amps go really high.
Click to expand...

My thoughts as well, make sure they are connected correctly and to the proper supply volts.

Also make sure they are all the same motor. If you somehow got one 1725 RPM motor and the other two were 3450, those two high speed motors will have more mechanical load on them driving the same blower with same ducting conditions.

Next thing is differences in ducting or whatever the air is flowing through. Less resistance to air flow means more volume of air will flow and that will add mechanical load to the motor. That air don't just move because you have a blower, the more air you are moving the more power is needed to be able to move it. Restriction to air flow causes a rise in static pressure but lowers volume being moved.
 
What happened to Darth Vader? Did he "flew the coup" ??

It would be good for the forum members if he returned and let us know what the problem ended up being...

MTW Ω
 
I once built a control panel for someone and got a call that the motor was burning up after connecting to it. I listened to the symptoms and figured that someone at the job site in Boston had strapped the motors for the wrong voltage. Nobody wanted to believe me, but the owner of the company flew from Seattle to Boston to check it out, because he was the one who made up the motor connections. I didn’t hear from him but 6 months later I found out from one of his electricians that I was exactly right. He was too embarrassed to let me know.
 
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