Water pump with a stinger

ptonsparky

Senior Member
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
Electrical Contractor
You have a small three phase pump motor. 208.
Service is 240v with Hi leg. (We don't care it has one. Your motor does not care)
What is the total distance to where your pump will be? VD can be your friend in this case. Two hundred feet of 14 cu @ 5.9 Amps will give you approx 223 volts at your motor. Within limits.

To confuse things a bit. Get a VFD that allows single phase input and gives you three out. Set the parameters to match that of the motor. I would use the two legs with 120v to ground because the VFD does care about the Hi Leg.
 

ActionDave

Moderator
Staff member
Location
Durango, CO, 10 h 20 min without traffic from wing
Occupation
wire pulling grunt
A 200 volt motor on a 240 volt system would be an issue whether you had a 3-wire Delta or a 4-wire Delta. Am I missing something?
The OP was less than clear about what his voltage was and what the rating of the motor was. We both agree that three wire or four wire system is of no consequence to the motor. I was focusing on the voltage rating.
 

curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
I'm surprised it was a 208 volt well pump. We just went though it for an upcomming project. Well contractor said the the only pumps he can get are 230 volt. The site has 208/120 & 480/277. He said we would need to install BB's to use the 208. Instead I recommended running 480 to the location then using a 480-240 XMFR. Distance is far anyway so the high voltage saves on wire cost.
 

ptonsparky

Senior Member
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
Electrical Contractor
I'm surprised it was a 208 volt well pump. We just went though it for an upcomming project. Well contractor said the the only pumps he can get are 230 volt. The site has 208/120 & 480/277. He said we would need to install BB's to use the 208. Instead I recommended running 480 to the location then using a 480-240 XMFR. Distance is far anyway so the high voltage saves on wire cost.
We have a customer that is 208. Available if you give enough lead time.
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
The motor design voltage for 208V systems is actually 200V. But most 230V new motors 10HP and under will say "208-230V" now, because it's cheaper for the motor mfrs to make a small design change than to maintain inventory on specific voltages. What they do is to design the motor as 220V +15%, -10% so that it covers the utility standards for 208V - 5% to 240V +5%. For them, it's just a change in the magnetics, for us, it's either buying different motors or using BB transformers.

What I think happens a lot is that equipment OEMs don't know enough to understand this issue and just put down the first number they see. But when you actually look at the specific motor NAMEPLATE, it will say 208-230V.
 
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Dzboyce

Senior Member
Location
Royal City, WA
Occupation
Washington 03 Electrician & plumber
What brand is the pump motor? Some brands are 240 volt only and have a different motor for 208 volt. The Grundfos is dual rated 208/240 volt 3 phase. Franklin and Pentair are not dual rated. Takes a different motor for 208 volt vs 240 volt. Guess which brand i use when I have 208 volt 3 phase?
 
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