230volt polyphase motor

Status
Not open for further replies.
I have a customer who purchased a 230/480 motor to run his propane distribution pumps for a new facility. If I understand my options for the service I could install a 208 Y system. I have been told to use a buck boost transformer to acomplish the higher voltages. 2nd I've been told that the motor will probalby run fine on the lower voltage. 3rd I could install a 240 volt delta system. However, some people claim the local power company will not install these anymore. 4th I've been told to install a single phase system and use a power inverter to get my 3rd leg and the system would be at the right voltage. I am looking for any suggestions or myth busters on this topic. Also, Why would you manufacture a 230 polyphase motor since that voltage is not standard?
 

iwire

Moderator
Staff member
Location
Massachusetts
It will likely work fine at 208 ...... or maybe not.

If it was me I would use two small buck boost transformers to get it up closer to 230 I think you would end up with 236. Cheap and reliable.

This chart shows recommended voltage tolerances.

ANSIC841.jpg
 
S m

S m

I am assuming this is a three phase motor rated for 230/480 volts. Looks like a European standard voltage. If this is an induction motor and you use it at 208/415 it will probably overheat due to high input current and burn. Not worth the risk. You can verify this by measuring the input current which will be higher than the rated current.

You have to get each phase voltage at near 240 volts and line to line at near 430 volts. Ideal will be if you can get a booster transformer.

I am not sure I understand your thought on Delta 240. In my thinking that will be a delta three phase 240 volts. Cannot work for a $15 volts system. If you put in all data you see on the phase plate we can get a solution.

Thank you,

SM
 

One-eyed Jack

Senior Member
In my area the 208 y tends to run at the upper end of the scale and we have little or no trouble . The 208 y is going to be your best bet. If you have 20 or more motors the buck boost with get you out of trouble on the few that want to have an attitude. Mount the trannys at or near motor starter and away you go.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Standard US motors have nameplate voltages of 230/460V. These motors are intended to be run on the equivalent nominal voltage systems of 240V and 480V.

This means if you have a 230V motor you should do your best to get as close to 240V as you can. I vote for boosting your 208V.

Saying that a 230V motor can be run consistently at the low end of its tolerance (-10%) on a 208V system, ignores the possibility that the 208V system may also drop by 10%.
 

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
I have a customer who purchased a 230/480 motor to run his propane distribution pumps for a new facility.
As others have said, that is an unusual spec. I'd lay my eyes on the nameplate.
If I understand my options for the service I could install a 208 Y system.
Many, but certainly not all, smaller (under 50 HP) motors are rated for 208-230/460. I emphasize the need to have complete knowledge of the nameplate; you'll need it for heater sizing too. Don't forget that 480 services are common in industrial applications. That motor, wired for 460, drops right in. Your starter might be (probably is) smaller on 460, as well.
 

stew

Senior Member
as others have indicated the best thing is to know what the nameplate says. 208/230-460 is a common nameplate voltage. Motors of this type are generally 1.15 or 1.25 service factor rated. most nameplates of this type or manufacturers specs are that when operated on 208 volts the service factor drops to 1.0 This is due to the somewhat higher current and hence motor heating. In most cases this is not a problem especially with pumps which typically are loaded evenly and do not see much spiking of load.
 
Status
Not open for further replies.
Top