Dangerous proceedure?

[wrsharper]

I am wiring up a 500HP star/delta motor but the motor taps for 5 and 2 are missing. Question: Is there any danger to normally wire up the motor and use either tap 5 or 2 and start the "uncoupled" motor in star only and check for bad current unbalance? If there is a bad current unbalance, then reverse 5 and 2. Tap 5 and 2 are the only two that I am not sure of. The rest of the tap and line connections would be correct.

 

[wrsharper]

Excuse, the first sentence should read motor tap identifier for tap 5 and 2.

 

[Marke]

Hello wrsharper

Usually, the stud pattern for the connections will give you the answer.
The studs are arranged so that links can be easily applied to put the motor into star config, or a different arrangment to put it in delta config.

A common arrangment is two rows of three studs. To connect in delta, use two links across either the top row of three , or the bottom row of three. To connect in delta use three links between the top row and bottom row.

Have a look at the pattern, (see if there are links in place) and you should be able to sort it from that. Failing that, connect as you think it should be in star and try it. If the currents are not right (around twice the rated current of the motor while the motor is at less than full speed) then you will have it wrong.

Best regards,

Mark Empson

http://www.lmphotonics.com

 

[wrsharper]

thank you marke for the advice about the stud pattern.