No output on generator

[boot45]

I have a 5 KVA, 1500 RPM 220 Volt generator manufactured by a company called Brush.
It has not been used for a number of years; there is little or no output the wiring seems to be ok.
Any ideas please keep it simple for a simple mind!

 

[ScottyUK]

Brush Electrical Machines are alive and well in Loughborough, England. They have remarkably good archives, although I am mildly surprised that they make an alternator so small. They used to be a big name in railway locomotives. Much of their output these days is either wind turbines or multi-MW turboalternators. The site has a slightly sad air of better times long since passed; there are a lot of empty spaces where once there was a hive of industry.

http://www.fki-et.com/index.cfm?company=bem

Other than that, what is the excitation arrangement? There should be a DC supply to the field, probably via slip rings but possibly through a smaller machine mounted on the main shaft which is fed DC to the armature and produces a 3-phase AC supply which is rectifed on the shaft to feed the field.

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Sometimes I only open my mouth to swap feet...

 

[2571]

Hi,
First, check circuit breakers, the check the condition of the commutator. Check the brushes, if they are not touching the commutator you get no voltage or little to the load. Check the commutator it has not ran in some time this can become dirty and cause poor continuity. Next, you can check the dc exciter. These are prone to go bad especially if you have not used it in a while. Talk to you soon

2571

 

[dpc]

in addition to the other good suggestions: You may need to flash the exciter field to get the voltage to build up, depending on the exciter type. When generator has been sitting for a long time, there is often not enough residual flux to bootstrap the exciter. Most machines provide for automatic field flashing, but you might want to check.

 

[waross]

On a machine that small, there is a good chance that the excitation may be supplied by capacitors.
(No brushes, no voltage regulator).
If so, check the capacitors, and "flash" the field by applying 12 volts DC to the load terminals of the generator when it is stopped.

 

[qassure]

You may as well check the insulation of the exiter field coils. Sticky brushes in the brush holder, dirty slip rings also the most probable causes.

 

[147anwar]

hi:
iam electrical engineer waddah from palestine and i used to make maintenance to electrical diesel generators,so if your generator is with brushes and you measure between pahse ad nuetral and you have more than 5 to 10,then that means both the statore an the armature are in good conditions,then check out that you have diode bridge and chech if the diode bridge is defected if not then check the slip rings on the rotating armature and the brushes are connected and delivering electric current to the diode bridge,some times you will fand acapacitor also if that capacitor id defected you will not have electricity,that is all that you can do for your generator,hopefully i had given you the tips for checking your generator