240 V single phase motor on 208V single phase

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Riograndeelectric

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Location
Lakewood Colorado
My customer would like to run this table saw on 208 volts single phase. Motor name plate ratings 1.5 HP motor 120/240V 13.6/6.5 Amps

The saw motor is listed as 120/240V only,building has 3 phase 208 Volt.

I understand most motors will operate at +/- voltage rating. Do I need to use a buck boost transformer to change the voltage to 240V or can the saw operate on 208V single phase?


http://www.ridgid.com/tools/ts3650-table-saw/
 
Rick Christopherson

Rick Christopherson

Senior Member
Reconfigure the motor for 120 volt power and give him a dedicated 20 amp circuit. Running a dual voltage tablesaw on 208 power would be worse than running it from a massively long extension cord and a series of power strips. :sick:

When DIYers (especially woodworkers) ask about reconfiguring motors, I typically tell them not to mess with it. In this case, not only are you not a DIYer, but here is a specific case where motor performance will be significantly improved at one voltage over the other, namely at the 120 volts versus 208 volts.

OH, I didn't see where this motor is already 120 volts. Leave it alone!!! Reconfiguring this motor for 240 on a 208 circuit will drastically reduce the available power.
 
stickboy1375

stickboy1375

Senior Member
Location
Litchfield, CT
ActionDave said:
It will probably run on 208. Most motors have 10% tolerance. What does the voltage read in his shop? Voltage where I live runs a little high, so 208 is around 212 to 215.

I would run on 120V before I used a buck boost.
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If it were my own, I might possibly run it at 208, but if I'm doing this for a client, i'm installing transformers to cover my ass....
 
Rick Christopherson

Rick Christopherson

Senior Member
stickboy1375 said:
If it were my own, I might possibly run it at 208, but if I'm doing this for a client, i'm installing transformers to cover my ass....
Click to expand...
What usually gets overlooked here is that when a woodworker approaches an electrician with this type of request, it is most frequently because the woodworker has been misinformed to believe that a dual voltage motor will perform better at 240 than 120. The motor doesn't care, only the voltage drop in the circuit matters. However, in this case, the voltage drop in a 120 volt circuit will be trivial compared to the voltage reduction in a 208 volt circuit.

It is my opinion that it should be an electrician's duty to properly educate the customer if the customer's request is not necessarily in the customer's best interest. This is a major piece of misinformation commonly associated with that hobby/business.
 
infinity

infinity

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Location
New Jersey
Occupation
Journeyman Electrician
Since the motor will run just fine on 120 volts that's what I would use. I see no reason to sell a customer a transformer that they don't need.
 
stickboy1375

stickboy1375

Senior Member
Location
Litchfield, CT
Rick Christopherson said:
What usually gets overlooked here is that when a woodworker approaches an electrician with this type of request, it is most frequently because the woodworker has been misinformed to believe that a dual voltage motor will perform better at 240 than 120. The motor doesn't care, only the voltage drop in the circuit matters. However, in this case, the voltage drop in a 120 volt circuit will be trivial compared to the voltage reduction in a 208 volt circuit.

It is my opinion that it should be an electrician's duty to properly educate the customer if the customer's request is not necessarily in the customer's best interest. This is a major piece of misinformation commonly associated with that hobby/business.
Click to expand...

I agree, but I'm answering the OP's question.
 
ActionDave

ActionDave

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Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
Rick Christopherson said:
What usually gets overlooked here is that when a woodworker approaches an electrician with this type of request, it is most frequently because the woodworker has been misinformed to believe that a dual voltage motor will perform better at 240 than 120......
Click to expand...
That and some guys just like to say "Yeah my table saw is 240".
 
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