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

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

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

(OP)
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?

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

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.

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

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.

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

2
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.   

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

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

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

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

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

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

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

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

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

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.

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

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.  

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

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!

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

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

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

Are you sure the points you have labeled 1, 2, 3 and where the green wire connect is not a copper neutral bar? It looks like at least one outgoing phase connection is the red taped conductor.
I would clean up and try to read the labels on the wires just to be sure.
 

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

It looks like copper but it is an insulating support strip. The strip supporting the outgoing cable connections is similar and it is bolted to the side of the case.

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

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

(OP)
I want to thank all those contributors to this thread who assisted in the school in the Philippines getting their generator working again.  With your help it saved them a considerable sum of money.

Stephen Franklin  

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

Tipped for caring to post the feedback. Good work by all the posters.

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