How do I find wiring diagrams for a 25 year old generator 9

[srfranklin]

The story is this. We have, on our school campus here in the Philippines a 100 KVA generator. The diesel was made in Germany and the GENERATOR in ENGLAND, so says the plate on the side.

The problem is that it is tapped to output 440 volts and we need 220, which it will do. We found that the company who made it went out of business in 1985. We have no diagrams of the wiring, which we need to get back up and running while our transformers and main board are repaired after the short. We need to have this operating this week which would save us over $1,000 a week.

I am attaching a picture of the plate which shows the manufacturing company and further technical details.

Can anyone help me?

 

[davidbeach]

How many leads are available? If only four as I think the nameplate implies, then you need to get a transformer to step the 440V down to 220V.

 

[nawao]

Is your load single phase or three phase load?
If is single phase load you have your 220v between each phase and the neutral. For three phase 220v loads you have two solutions:
a)get a transformer to step the 440V down to 220V.
b)change the alternator connections. If is a 12 wires stator you can parallel the windings instead of series them. Be carefull not to shorth circuit any winding. Without
diagram is not ease but you can try.

 

[ccjersey]

By the name plate, it's a dual voltage wye connected set.

If the voltages were listed as 440/250 or other "wye" ratio voltages, I would expect that it has only 4 leads and is not reconnectable. Since it is listed as 440/220 which does not fit with a wye connection as shown on the tag, you should find 9 labled output leads and perhaps a tenth one which will be a neutral.

I would examine the connection cabinet of the generator for a diagram showing not only how to connect the stator leads, but also how to configure the exciter/regulator connections. Here is a general diagram of the stator lead reconnection from series (high) wye to parallel (low) wye.

http://www.smokstak.com/forum/attachment.php?attachmentid=3483&d=1125167403

Remember, this does not configure the exciter/regulator connections! Failure to connect those correctly will likely damage the generator immediately upon startup.

 

[chicopee]

As ccjersey points out, there s/b indelible inscriptions or diagram of the tap connections inside the housing for the two voltages.

 

[waross]

Well said, ccjersey; A star for you!
There is a connection sketch on the nameplate showing a neutral.
I suspect this is a ten lead machine.
What are your loads?
Do you need single phase or three phase?
Do you need a neutral?



Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[BSEE1980]

This should work fine for what you need.

I suspect you have a 10 or 12 lead machine: how many wires in the term cabinet?

If they are not marked, it is possible to determine the polarities.
Use a VOM to find winding pairs.
Use a AC source and VOM to find windings of the same pole pair.
Use a battery and VOM to determine inst. polarity and Y connection point.

This is not that hard: keep your basic electricity theory in mind. I used to teach AC machine theory for GE and this was one of our labs!! We had a 12 lead machine with no markings on the leads. The students had to find the right connection.

If you want more help, let me know. It is kinda long for this format.
Good luck,
Steve

 

[srfranklin]

Thanks for all your feedback - I've managed to get some more photos of the generator in the Philippines which will hopefully answer most of the queries so far listed.

I do appreciate all your contributions

Stephen

 

[srfranklin]

photo 1

 

[srfranklin]

photo 2

 

[srfranklin]

photo 3

 

[srfranklin]

photo 4

 

[BSEE1980]

I really cannot see the power connections very well, sorry.

Of course, when you change the voltage, you will need to change many other things: protective settings (50, 51, 32?, 40?, 59, 27, basically any voltage or current based protection), AVR settings, etc.

And if they are older electro-magnetic relays, they may need to be replaced.

Do you have wiring diagrams on this unit?

A transformer might be faster...

good luck
Steve

 

[srfranklin]

photo 5

 

[srfranklin]

photo 6

 

[srfranklin]

photo 7

 

[nawao]

Is a 12 lead stator. You only need to move the pairs 1, 2, 3 and the green sensing wire. Label this wires and make an sketch should in case you need to come back to actual situation. Carefully open the three pairs and test continuity pair by pair. Connect the lead given continuity to line side to neutral point and the one given continuity to neutral point to line side. Do it pair by pair. Carry the green sensing wire to line side not to neutral. Since the AVR is sensing at a mid point I don't think you ned to change anything on the AVR. Good luck.

 

[nawao]

Is a 12 lead stator. You only need to move the pairs 1, 2, 3 and the green sensing wire. Label this wires and make an sketch should in case you need to come back to actual situation. Carefully open the three pairs and test continuity pair by pair. Connect the lead given continuity to line side to neutral point and the one given continuity to neutral point to line side. Do it pair by pair. Carry the green sensing wire to line side not to neutral. Since the AVR is sensing at a mid point I don't think you ned to change anything on the AVR. Good luck.

 

[glendale]

The company was taken over by Brush Electrical Machines Ltd 20 years ago. Try there service department in the UK Tel 44 1509 612616. May still have records, worth a try anyway!

 

[waross]

srfranklin;
A couple of unanswered questions that may be important.
440/480 volt systems often run without a neutral.
220/240 volt systems more often require a neutral.
What is the normal voltage in your country?
What are your loads?
Do you need single phase or three phase?
Do you need a neutral?

Bill
--------------------
"Why not the best?"
Jimmy Carter