Flygonkick
Member
- Location
- Michigan
- Occupation
- Electrician
I have a 2HP 115/230v pump being installed where I work and I wanted to get opinions on if it would be okay to run 208 to the motor or if I should get a step up transformer to 230 or 240
Is 208v acceptable in a 2hp 115/230v motor
- Thread starter Flygonkick
- Start date
ptonsparky
Tom
- Occupation
- EC - retired
Personally, I wouldn’t worry about a pump.
ptonsparky
Tom
- Occupation
- EC - retired
Our 208 always seemed to be closer to 212 and low voltage seldom an issue with any.
Flygonkick
Member
- Location
- Michigan
- Occupation
- Electrician
The main reason I'm looking at using the 208 or even a step up transformer is because the 208 panel is within 50 feet of the pump installation and the 120 panel is closer to 100 yards away. Gotta love old school buildings.
So no neutral in the 208 panel.
In that case, I agree with others - run it on 208V. I would check the running amps after startup to confirm they are not greater than the service factor amps.
Joethemechanic
Senior Member
- Location
- Hazleton Pa
- Occupation
- Electro-Mechanical Technician. Industrial machinery
Is it a submersible? How long does it run? Are you near maximum flow and head?
Although I probably wouldn't worry about it. Probably cheaper to rewind or replace the stator for 208 than to buy the boost buck transformer, although you'd only need one
Although I probably wouldn't worry about it. Probably cheaper to rewind or replace the stator for 208 than to buy the boost buck transformer, although you'd only need one
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
I would want to know whether the manufacturer's data has anything to say about it.
ptonsparky
Tom
- Occupation
- EC - retired
Maybe how long is it running at FLA or SFA.
Critical or well shucks, get one ordered next week?
Birken Vogt
Senior Member
- Location
- Grass Valley, Ca
It completely depends on the load placed on the motor.
If the motor is lightly loaded, no worries, current will be way under the rating.
Something like a small Honda generator with a knob that could be dialed back to 208 volts is one way to test this before going to all the trouble to construct it.
If the motor is lightly loaded, no worries, current will be way under the rating.
Something like a small Honda generator with a knob that could be dialed back to 208 volts is one way to test this before going to all the trouble to construct it.
A motor made to run in 230 volts should never have less then 95% of nameplate voltages. So 230 × 0.95 = 218.5 volts so it should not be supplied by 208 volts. Too often have been in plants that had 208 volts and during hot summer days measured 190 volts at load side on motor starters. You could install a buck / boost transformer to raise the existing 208 volts to 230 volts.
ptonsparky
Tom
- Occupation
- EC - retired
and I thought it was +-10%
- Occupation
- Licensed Electrician
Motors are good +- 10% of nameplate voltage, most 208V systems run around 215V. If the motor is made in the last 20 years a closer look at the nameplate prolly says it can be used on 208V.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
Check with the MFG. I always say within 10% of nameplate. Some motors rated 230/240 are also marked "suitable for use on 208 volt" but that may have been 3 phase
I have to disagree with 10% + or - of motor nameplate voltage is too high. Did some searching on Google and found a few interesting articles. First ECM MAY 2000 had an interesting article by Mr Ed Cowern that stated a 10% voltage reduction reduces starting torque to only 81% which would be a problem for a motor with a full.load. NEMA MG1. 12.44 recommends a maximum of 6% + or - of motor nameplate voltage.
But NEMA says +-10%.
So what gives here?
The Meaning Behind Motor and Multi-Motor Markings - Technical Articles
Learn what motor and multi-motor equipment markings required by the National Electrical Code mean.
eepower.com
Deltaforce
Member
- Location
- India
- Occupation
- Electrical Engineer
208v nominal voltage, see actual voltage variation on motor terminals within nema10%+_ motor nominal 230v
- Occupation
- Licensed Electrician
There a 230V motors everywhere running on 208V. Most of them say you can use them at 208V on the nameplate. It's rare to find one that has a problem, and the ones that do it is usually a problem caused by something other than the motor.
ptonsparky
Tom
- Occupation
- EC - retired
I've put B/B transformers on A/C units before but that was a looong time ago. 240 volt 1 ph units fed from 208 3 ph. Set on a metal roof so they were going to be working hard a good share of the time.