Delta Connection in IM

It does not matter which way you connect to form the Delta. Only the direction of rotation of the rotor will change between these two connections. I suspect the inertia of the connected load, undervoltage at the motor terminals, harmonics in the power system, etc.

Use a tongle tester to check the current in 3phase after motor is turned ON. Give the motor back for whome you gave for rewinding to reconnect the terminals to star or delta.

10:1 odds says you have a digital ammeter and you have the "Peak" switch left on so it registers the peak and does not drop down again on the meter display.

It looks you have an IEC (new) motor with 6 leads terminal. The motor nameplate should have the detail connection information and you can get it from there. You first need to know the required connection configuration (Star or Delta) for the voltage that you are applying. Then connect as follows:

In case of Delta, U1-W2, V1-U2, W1-V2 and provide the supply to U1, V1, W1

In case of Star, U2-V2-W2 and provide the supply to U1, V1, W1

See this link for more detail

http://hollandindustrial.com/PDF%20Files/European%20and%20American%20Motor%20Connections.pdf

- MS

Wrong answer in My case. You need to discuss this with the MFG. I have 44 5.5 KW pumps that were "wired by the factory to be wired in WYE for 480V" They sent them wired Delta 480V and never told any one till we burned out 6 of them. Then said, Oh , we re-wired them specifically for you to run in DELTA @ 480V. None of the info on the motor name plate states this, nor does any info accompanying the motors/pumps indicate this. Bottom line, the pumps are wrong anyways and the MFG is replacing all of the 5.5KW to 7.5KW as what was specified in the beginning and these will be WYE configuration. So don't go by what is on the name plate. Test the windings first when dealing with EU motors. Take that extra step. Be safe.

We are seeing the same thing with smaller motors coming as 415V Y / 240V delta connectionfor the same motor. Many have been connected 415V delta and failed due to high amps.

This is confusing.

If they were wired to run Delta on 480V, and you supplied 480V to them, then they are OK and can run! Your problem, as it transpires later on in your comment, is that the motors were under-rated and they sent you 7.5 kW motors instead of the 5.5 kW motors that burned.

@msamad I only want to know that what will happen If I connect it in U1-V2,V1-W2,W1-U2 manner(Delta) ??? Because when the motor shipped at our location, it was connected in that manner.

Nothing will happpen, the motor will just run the same way

Electrical, there is no difference in a connection U1-V2 and V1-W2 and W1-U2

or U1-W2 and V1-U2 and W1-V2.

In both cases you connect the windings in delta.

In both cases the motor will even spin in the same direction if the supply sequence remains the same. Ita est :

• L1 is connected to U1
• L2 is connected to V1
• L3 is connected to W1

Please check if your supply voltage matches the motor voltage.

If your motor is 400V delta / 690V Wye

and your supply is 220V it will never work......

Check the data plate of the motor first,the connection if it is for delta,the voltage given in the data plate for the delta connection must agree with your available source voltage.

For example:3-phase,Δ/Υ,220V/415V.You should connect this motor in delta(Δ),if your 3-phase source voltage is 220Volts.You should connect this motor in star(Υ),if your 3-phase source voltage is 415Volts.

Note that your delta connection should be U1-W2,V1-U2 and W1-V2,while your supply should be L1-U1,L2-V1 and L3-W1.Your star connection should be W2-U2-V2,while your supply should be L1-U1,L2-V1,and L3-W1.

If the data plate states that the motor can be star-delta connected to the line,then you use a star-delta starter for the motor.Ensure that your motor front/end bearings are very free to avoid taking higher currents.

Pls,ensure that your protection devices are given adequate ratings and settings.

"If the data plate states that the motor can be star-delta connected to the line,then you use a star-delta starter for the motor.Ensure that your motor front/end bearings are very free to avoid taking higher currents."

This is not normally stated like that. If the motor is rated in Δ for 415 V and there are 6 wires coming out, then you can use it with a star-delta in a 3 phase supply with Line-Line volts = 415 V.

Please check the polarity of the motor coils by approved method.Then make connections as already stated(Star or Delta). Ensure that the motor rating is correctly selected in respect of Kw capacity,Torque requirement, GD^2 value of the load(driven equipment)&GD^2 value of the motor and correct selection of the voltage rating, starter connections. Then only switch ON the power supply.