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Mike G.
Mike G., Master Electrician
Category: Electrical
Satisfied Customers: 7534
Experience:  Proven Professional 48 years Experience
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Hi there, I have a westerbeke Westerbeke 6BTD 6.0 8 kw (it

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Hi there,
I have a westerbeke Westerbeke
6BTD 6.0 8 kw (it actually has 6 and 8 BTD) stamped on the name far as I can see the 8BTD is the one I have as it's running 120 vac at 60 hertz..
I believe the main breaker and wire is underrated as they have 2, 10 AWG running to either side of a 30 amp double breaker..then a length of 8 AWG to the distribution panel..
Shouldn't this just have a piece of 6-8 AWG wire from the gene to a 50/60 amp breaker?

Hi, I'm Mike and I'll be glad to assist you. Should be a #8 copper on a 2 pole 40A breaker


6.09KW = 6080 watts

6080 watts X 1.25 = 7600

7600/240= 31.4 Amps


Step up to next size breaker

0ver 30A - step up to #8 wire

Customer: replied 3 years ago.
Thanks Mike..
If I just want 120 vac to come from the gene like it is wired..would that not be 66 amps for 120 and 33 for 240?
The small bar is connected inside the gene for 120 /60 can I not just take a 8 AWG stranded marine wire through a 50 amp breaker..sorry it's not 240..just 120..
Hope I'm making sense :)
I took some pictures I wish I could show you them so you could see!!
At 120 you'll need to wire it with #6 on a 60A breaker
Mike G. and other Electrical Specialists are ready to help you
Customer: replied 3 years ago.
Thanks so much for your help Mike,
I have a few pictures of how this generator is wired now..I would love if you could see it just to verify I'm doing this right when I change it!!
Can I upload anywhere on this site??
Would I use just a single 60 amp breaker or a double 60 and just wire it through one side??
It has a double 30 amp fitted now ,and that would be for 240 right? (One side for each leg)
It's the breaker I'm getting confused with..I can't see a way to run it with both windings tied together in the generator, for full120/60 through the double 30 amp now?
Any way to post these pictures to you?
Thanks so much Mike!
Use and give me the URL.
Customer: replied 3 years ago.

Hope this works ...
The 2 10 AWG wires go to a double 30 amp on each side then a 8 AWG to the 2 panels in the boat..
Should I just take the 2 wires off and replace with a 6awg and run through a 50 amp breaker (single breaker??) thanks so much!
After reading your statements again and seeing the picture, I would say that you need to use the 1st answer given . The output of the generator is 120/240V and the 2 pole 40A breaker with #8 wire is the only way to install the feeder. You can't combine the 2 legs got a larger amperage of 120V.
Customer: replied 3 years ago.

This is the tag for 120 vac.. This is really starting to confuse me now..
Your picture shows 2 blacks & 1 white wire. this is 120/240V. You have both voltages as an output. black to black is 240V. Either black to the white is 120V. The generator output is as the first calculation given. You can't increase the 120V by installing a larger wire. You will have the potential of 2 individual 30A 120V circuits. That is a 60A capability not to exceed 30A per leg.
Customer: replied 3 years ago.
This is what's confusing me..the 2 black wires inside the gene box are connected to the same jumper for 120 vac..
The gene is producing 120 not 240..(wouldn't it be better to run a single 6-8 AWG instead?
I don't want to run 240 to the panels inside the boat and split the legs as they will run the gene off balance..
What's the amp difference if you put the jumper in place to produce 120 only..
I understand you can run it 240 and each leg would be 30 amps..I'm trying get maximum power with the jumper at 120..
Thanks Mike!
If yputest the voltage you'll see that each black to white is 120V and that black. to black it is 240V. You need to bring 120/240V to get the maximum power. You can't put the blacks together.
Customer: replied 3 years ago.
If you look closely at the small picture..the 2 blacks are both connected to a small link bar..that's why I didn't understand why they had put 2 wires on the same connection,then split it through the 30 amp's 120vac from either black to white and 0 between black to black..
Can you see the diagram for 120vac..that's what's inside the westerbeke..
thanks for bringing that to my attention. The diagram shows it is 120v. and you may run a 60A feeder. It only means using a larger wire.
Customer: replied 3 years ago.
Thanks Mike!
I guess after everything we've talked about,I still don't know how to wire the breaker and what size breaker..
If we're both on the same page now that it is 120 vac..Should I run a 6 AWG from the generator connection board, to a 60 amp breaker? (Single or double)
From the diagram I connect the neutral to the I run the neutral through the breaker also..
For 60A you only need a single pole breaker and the neutral does not connect to the breaker. #6 wire will do.
Mike G. and other Electrical Specialists are ready to help you
Customer: replied 3 years ago.
Ok perfect..thanks for all your help Mike!
I think the 3 terminals on the left are the output, being the larger wires. The double connections are internal to the generator.