Taylorwoorobertson
Member
- Location
- Kansas
I have a 220V/60Hz open refridgerator that uses 13 amps. Can I use this with a 208V system?
220V and 208V
- Thread starter Taylorwoorobertson
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kwired
Electron manager
- Location
- NE Nebraska
Likely you can. Does it actually say 220V on the nameplate? If so it is just about as questionable if it can be used on a 240 volt system, but if allowed to be used at plus or minus 10% then both are covered.
more information is necessary.
erickench
Senior Member
- Location
- Brooklyn, NY
No. It would have to be a 240 Volt system. The reason why it's rated at 220 volts is because of the voltage drop in the branch circuit conductors.
kwired
Electron manager
- Location
- NE Nebraska
I will not say that is necessarily wrong, but I find it more common to see equipment (especially motor driven) rated for 230 volts with that being the likely reason.
Generally if a motor is rated 10 amps at 230 volts that means when it is delivering its rated output power it will draw 10 amps if the input voltage is 230 volts. Change anything variable and most others will change also (frequency is usually an exception, if the supply is strong enough to sustain frequency)
Taylorwoorobertson
Member
- Location
- Kansas
From my understanding is that it will work but the chiller will take longer to chill but not noticeable to the customer.
kwired
Electron manager
- Location
- NE Nebraska
Motors don't work that way. The speed of the motor is based on the number of poles in the windings and the frequency of the input current. The motor is going to try to achieve the same speed and same output power as long as the frequency remains the same. That means if the voltage drops the current is going to go up but the same amount of work will be done, but at the expense of more heat in the motor windings which over time may damage the windings.
Too severe of a drop in voltage will mean more slip and less torque in the motor output shaft and even more rise in current likely causing catastrophic failure in windings if overload protection does not open the circuit.
Now if you supply the motor with higher than nameplate voltage you have the opposite to some degree. It is still going to try to run at the base speed according to input frequency, but with a high input voltage the current is going to be lower at the same output level. But you can not raise voltage too high or you will go to and beyond saturation of the magnetic coils and will start to have increased heating effects from that.
So the basic answer to your question is yes the motor will run on 208 volts. It will draw more current when doing the same work than it draws at 220 volts. The real question is can the motor insulation take the increased heating it will encounter in the application?
That is something most of us can not give you a definite answer for, but in most cases it will work, may have a shortened life but end of life is probably years away and not hours.
Too severe of a drop in voltage will mean more slip and less torque in the motor output shaft and even more rise in current likely causing catastrophic failure in windings if overload protection does not open the circuit.
Now if you supply the motor with higher than nameplate voltage you have the opposite to some degree. It is still going to try to run at the base speed according to input frequency, but with a high input voltage the current is going to be lower at the same output level. But you can not raise voltage too high or you will go to and beyond saturation of the magnetic coils and will start to have increased heating effects from that.
So the basic answer to your question is yes the motor will run on 208 volts. It will draw more current when doing the same work than it draws at 220 volts. The real question is can the motor insulation take the increased heating it will encounter in the application?
That is something most of us can not give you a definite answer for, but in most cases it will work, may have a shortened life but end of life is probably years away and not hours.
- Occupation
- Licensed Electrician
I agree with kwired. It will likely work fine, but there is no way to say for sure.
If there turned out to be a problem put in a buck/boost or different motor.
If there turned out to be a problem put in a buck/boost or different motor.
erickench
Senior Member
- Location
- Brooklyn, NY
I'm looking at a table in an old IEEE Grey book. The following voltages are associated with a 120/240 system: 110/220. 115/230, 125,250. So even though it may work on 208V system proper practice would call for it to be connected to a 240V system.
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