I would think so. If current equals voltage divided by resistance then halving the voltage would cause current to increase dramatically. Over a 2 month period of subjecting a 240v motor to overcurrent conditions would easily kill it.

 

I would think so. If current equals voltage divided by resistance then halving the voltage would cause current to increase dramatically...

??

 

I would think the motor would go off on IOL. Probably not the best thing for such a long time. I would not be surprised if after it was wired 240 it took right off. Had a unico run the same way for over a year, when the airflow was crap i found it. Went back couple yrs later and the unit was humming along fine

 

would the control transformer perform well enough to even energize the blower relay?

 

first thing i thought.

 

^ ohms law stuff.


I agree with the guy who pointed out the transformer issue, the system should have never run.

 

^ ohms law stuff.


.

Only in Bizarrio world.

 

Resistance divided voltage... close enough eh

 

First of all, forget about resistance. Wiith AC devices, it's impedance, which is much different than resistance.

Second, if you keep the impedance at the same value and you reduce voltage, you reduce the current through that impedance.

Because motors spin, and the spinning affects the amount of counter emf being produced, current is affected by the potentially slower spinning when voltage is lower than the design voltage.

To answer the op's question, yes, the motor can be damaged. It depends on how and how well the motor is made, and how much load is placed on it.

 

If the transformer somehow provided enough control voltage, and the blower motor was an ecm type, I believe it would work.

Sent from my Torque using Tapatalk

 

Most appliances are designed to operate with in +/- 10% of their rated voltage. (School basics)
So the original question would be MOST likely it's damaged....
As for the transformer.... What was the promary rating and was that provided, if not, it too may be bad.
(So, the motor may have operated).

Yuma,

 

Would go on overload pretty quick or provide so little airflow causing other issues. Would be red hot as well

 

Ok, long story.

Tech shows up, customer says place was remodeled last year, unit "worked fine last year, after remodel".
Straight cooling Air handler/AC.

Tech finds 120 to unit.
Finds 13v on low voltage.
Changes transformer wiring to 120. Motor spins slow, flips breaker off.

Calls me, wants to know if he can change the motor to a 120 motor.
Tell him: "absolutely not. You've modified that unit's UL. tell them it needs to be 220. You can charge them to fix it if you want, just make sure it's a homerun."

Calls me back:
"'**** dude, ****. The motor threw sparks when I changed it. The guy is on his way home from work, and doesn't want me to touch anything electrical, because he wired the whole house.'

'fine, put the electric back. That motor is smoked. I don't care what he says, he broke it.'

guy gets home. Tech tell him he smoked motor, doesn't believe him. Switches wiring real quick at panel, motor throws sparks and runs. Says "see, it's fine."

Anyways, what a cluster.


Here's another one.
Lets say I had a 220 fan motor that I needed to spin the opposite direction, and didn't have the yellow/orange leads you can switch, lets say it's a stock motor.

brown = cap, black = L1, blue = cap common (L2)

If I switch brown/blue, on the capacitor, the fan will run backwards.
Checked my amp draw, looks good.

Will it kill the motor?