Delta connection

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18-12-2018, 05:15 PM
OkonedoCharles

Delta connection

Good day Engineers
Please I need urgent help.
I'm not that grounded in electrical.

I connected a compressor today and the result was a blast.. Breakers trip and compressor burnt.
The compressor was rewound while the 6 terminals connected with jumpers.
Thus making it 3 lines to connect the 3 phase.

My question is that can I connect the 3 phase from any side of the jumpers. That is either from 1, 2, 3 or 7, 8, 9
18-12-2018, 05:42 PM
Brian_UK

Re: Delta connection

Maybe this will help....

https://www.google.com/search?client...7vQtHp-bym3WM:
18-12-2018, 08:39 PM
nike123

1 Attachment(s)

Re: Delta connection

If compressor is burnt than that mean it was wrongly connected in first time. Give us picture of compressor nameplate and give us data of Nigerian voltages of 3 phase system. Then we will be able to help you to correctly connect compressor. Do not connect it in current jumper configuration since it will probably burn again!

As I can see, your country have 400V 3 phase system.
If motor nameplate say 230Δ/400Y than it could be connected only in star winding configuration, and delta is not option for your country, except if you using frequency inverter configured to run with 230V.

Attachment 15320

In your country you can use delta configuration only with motors rated to run delta on 400V (400Δ/400Y or 400Δ/690Y)
19-12-2018, 01:57 AM
OkonedoCharles

Re: Delta connection

Thanks a lot Mr. Nike.
Going with your clear explanation, which says L1 to U1, L2 to V1, L3 to W1... What will happen if I mistakenly connect L1 to W2, L2 to U2 and L3 to V2.
Referring to your Delta Connection Diagrams.

Thanks
19-12-2018, 10:19 AM
hyperion

Re: Delta connection

As U1 is linked out to W2 it does not really matter which terminal you connect L1 onto. It is just conventional to connect onto U1, V1 and W1.
19-12-2018, 03:50 PM
OkonedoCharles

Re: Delta connection

Thanks hyperion
19-12-2018, 05:07 PM
nike123

Re: Delta connection

Quote:

Originally Posted by OkonedoCharles

Referring to your Delta Connection Diagrams.

I think you missing point of my post which is reason why your motor is burnt in first place. I am not sure that you can connect your motor in delta configuration.

But if you asking in general, than it makes no difference from which side of delta connection you supply power (U1,V1,W1 OR U2,V2,W2) as Hyperion already explained.
20-12-2018, 07:10 PM
OkonedoCharles

Re: Delta connection

Thanks Mr. Nike!
I got you. Though the connection I did was right, yet the Carlyle compressor winding got shortened to body.
Again the ways the coils read to each other got me confused.
Considering the terminal, T1, T2 and T3 all read to each other ( resistance), while T7 T8 and T9 also read continuity.
Jumpers were used to link T1 to T7, T2 to T8, and T3 to T9.
I was not expecting T1, T2 and T3 to read continuity, likewise T7, T8, T8.
20-12-2018, 07:58 PM
Brian_UK

Re: Delta connection

Let us start again, this time from the motor starter.

How is the motor started?

Is it direct on line, star/delta, part wind ?
21-12-2018, 08:05 AM
nike123

Re: Delta connection

By numbers mentioned (T1-T3, T7-T9) It is probably part winding motor! Where are T4-T6?
That is why I asked first to:"Give us picture of compressor nameplate"!
21-12-2018, 10:12 AM
OkonedoCharles

Re: Delta connection

Direct on line
21-12-2018, 10:17 AM
OkonedoCharles

1 Attachment(s)

Re: Delta connection

Quote:

Originally Posted by nike123

By numbers mentioned (T1-T3, T7-T9) It is probably part winding motor! Where are T4-T6?
That is why I asked first to:"Give us picture of compressor nameplate"!

Attachment 15321 Attachment 15321 Attachment 15321 Attachment 15321 Attachment 15321
21-12-2018, 10:20 AM
OkonedoCharles

1 Attachment(s)

Re: Delta connection

Attachment 15322 Attachment 15322
21-12-2018, 01:02 PM
frank

Re: Delta connection

Here is a link to the 06E service Manual.
https://www.utcccs-cdn.com/hvac/docs...06/020-611.pdf
Electrical connections start around page 108
21-12-2018, 02:32 PM
OkonedoCharles

Re: Delta connection

Thanks a lot Mr. Frank
21-12-2018, 03:32 PM
GHAZ

Re: Delta connection

Hi looking at the compressor photo, it is a 50% part wind and your wiring is OK, I think it might be a problem with the stator or the rotor bars
21-12-2018, 05:15 PM
Brian_UK

Re: Delta connection

Quote:

Originally Posted by GHAZ

Hi looking at the compressor photo, it is a 50% part wind and your wiring is OK, I think it might be a problem with the stator or the rotor bars

Can you please explain how it is a part wind with the wiring scheme shown.
22-12-2018, 12:31 AM
nike123

1 Attachment(s)

Re: Delta connection

Hi Brian!
According to nameplate picture, motor is internally connected in star (or delta) configuration and cannot be in field modified.
When connected 3 wire +PE with bridges, it is direct on-line start (2 windings in parallel => 100% starting current).
When connected with 6 wires +PE without bridges, than it is part winding. In that case 2 contactors are used with one with time delay at start (1 separate winding at start for time delay => 50% starting current).

As OP stated earlier, it was bridged as in picture at right side of motor nameplate which is direct on-line connection.

But we still don't have full model number to verify correct voltage is applied. If compressor previously worked in Nigeria on direct line voltage, than it is probably of correct voltage.

Attachment 15324

All that above said is under presumption that motor rewinding is done exactly as original is wounded in the factoy.
22-12-2018, 11:13 AM
redroge

Re: Delta connection

How about a photo of the contactor(s)
22-12-2018, 03:00 PM
Brian_UK

Re: Delta connection

Thanks Nike, I do understand the part wind scheme but was asking because the OP stated it was a DoL starter and I couldn't see how part wind could be applied that way.