# Electrical dyanamo



## syed.nifty (Mar 16, 2014)

Dear All my fellow electricians & engineers,

Greetings, 
I have come across electrical problem with dynamo.
The voltage is giving less, and when any heavy load operates, it trips the dynamo.

As I started with checking the copper braids connected to the brush holders.
Adjusted the copper braid for one set of brush , that was for the neutral line.
As for the three phases , there are sort of ok. 

Then we started the dynamo, there was same problem.
So, i checked the brushes, they dont have proper contact, so i have again adjusted them.

Once again, we started still the same problem.
Now, this time I have checked with multimeter, i find out that
1. L1- L2 = 1.7 VOLTS
2. L2 - L3 = 92 VOLTS
3. L3 - L1 = 92 VOLTS

AND

1. L1 -N = 39 VOLTS
2. L2 -N = 25 VOLTS
3 L3 - N = 50 VOLTS



Also, i have checked continuity between the line brush holders of the line voltages and the neutral, and there is not continuity. I have checked there is very high resistance between the line voltages to the body of the dynamo. 

Now, since we dont have any copper braids, lugs and the carbon brush, so, i will try again tomorrow.

Please kindly advise me some thing so that the dynamo starts running.
I will appreciate any response and thanks in advance


Thanks
Sd nifty
Electrician


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## circuitman1 (Mar 14, 2013)

what are the output voltages supposed to be? are all the slip rings or comuntators clean & shiny? do you have a service manual on the unit in question?:001_huh:


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## syed.nifty (Mar 16, 2014)

Hi there,

This old dyanamo, for which i dont have any manual. The output voltages , im not aware of as there is no number plate or somethink to look at. The only thing i know its 3 phase, 1 neutral .
yes, the slip rings are clean and shiny.
Thanks once again.


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## circuitman1 (Mar 14, 2013)

on this side of the pond that would be a 120/208 system.is this dynamo in a power plant?it would really hard to say without a nameplate. is there anymore like this around that you could get the data off of?


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## syed.nifty (Mar 16, 2014)

circuitman1 said:


> on this side of the pond that would be a 120/208 system.is this dynamo in a power plant?it would really hard to say without a nameplate. is there anymore like this around that you could get the data off of?


Hey there, 
I was away from the network , as i travel. The dyanamo was hand driven , its used in the small cargo boat. I couldnt attend it anymore as it has left from the port.

They have only 1 .

Thanks


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## bobelectric (Feb 24, 2007)

They left with 0 electric? Was this a sailboat?


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## gnuuser (Jan 13, 2013)

without being there to megger it this sounds like it may be an arcing short between l1 and the ground or body.
a short of this type is not a full contact short and may show a high resistance reading with an ohmeter 
in operation the generated potential may exceed the resistance of the small air gap and start arcing inside the dynamo
the sound of the arcing would be masked by the operating noise of the dynamo and other equipment


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