Bigger generator hook up??

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Fighterpilot

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Apr 17, 2011
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Taking out the old Westerbeke 4.4, 120 volt gen. and replacing with same vintage Westerbeke 8.0 generator. Both WMDs. Will try to find schematics but until I do would welcome any advice. The first issue is the boat is only wired for 110. The 8.0kw has two 120 leads vice the one set that was hooked to the smaller generator. But the shore power has two connections, one for A/C only and the other for the boat which suggests I might be able to bring one leg of the generator to the A/C only side and the other leg to everything else on the boat. I would have to run another lead from the generator with the other 120 current on it and get it hooked into the circuit somehow up on the main bus. The exisiting lead from the old generator is now hooked to feed everything, so would have to find that connection and make a change. I'm assuming that if I ran but one 120 lead from the bigger generator I wouldn't have available the full amp capacity of the bigger generator. Is my general reasoning right??

Do any of your Califonians have the bigger generators with the 220 or the two 120 leads wired into it? Suspect it wasn't a 220 bus if you have the 220 capability, but rather two 120 circuits from the generator.

I'm only going to have $500 dollars plus my old generator invested since my mechanic took the generator as payment for work done and planned to put it on his boat. It wouldn't fit so he wants a smaller generator like mine for his boat.
 
Taking out the old Westerbeke 4.4, 120 volt gen. and replacing with same vintage Westerbeke 8.0 generator. Both WMDs. Will try to find schematics but until I do would welcome any advice. The first issue is the boat is only wired for 110. The 8.0kw has two 120 leads vice the one set that was hooked to the smaller generator. But the shore power has two connections, one for A/C only and the other for the boat which suggests I might be able to bring one leg of the generator to the A/C only side and the other leg to everything else on the boat. I would have to run another lead from the generator with the other 120 current on it and get it hooked into the circuit somehow up on the main bus. The exisiting lead from the old generator is now hooked to feed everything, so would have to find that connection and make a change. I'm assuming that if I ran but one 120 lead from the bigger generator I wouldn't have available the full amp capacity of the bigger generator. Is my general reasoning right??

Do any of your Califonians have the bigger generators with the 220 or the two 120 leads wired into it? Suspect it wasn't a 220 bus if you have the 220 capability, but rather two 120 circuits from the generator.

I'm only going to have $500 dollars plus my old generator invested since my mechanic took the generator as payment for work done and planned to put it on his boat. It wouldn't fit so he wants a smaller generator like mine for his boat.
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First I would say, hire someone with Marine Electrician experience to wire it up for you.

I'm not all that familiar with Westerbeke, so you want to confirm this with someone who has expertise with that unit.

Yes you can run two 120 circuits, they're probably going to be two 20 or 30 amp services each. The problem you're going to run into, wiring it the way you are suggesting, is generators generally wants to see a balanced load. So if your air conditioning is running off one circuit and your house circuits off the other. Then you could be pulling 20 amps off one circuit and two or three amps off the other. Which could overheat the windings and damage your generator. If you have two A/C units, then better to split them between the circuits.

In any case have a pro look at it and divide up the loads properly for you. Let us know how that works out for you.
Larry B
 
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Taking out the old Westerbeke 4.4, 120 volt gen. and replacing with same vintage Westerbeke 8.0 generator. Both WMDs. Will try to find schematics but until I do would welcome any advice. The first issue is the boat is only wired for 110. The 8.0kw has two 120 leads vice the one set that was hooked to the smaller generator. But the shore power has two connections, one for A/C only and the other for the boat which suggests I might be able to bring one leg of the generator to the A/C only side and the other leg to everything else on the boat. I would have to run another lead from the generator with the other 120 current on it and get it hooked into the circuit somehow up on the main bus. The exisiting lead from the old generator is now hooked to feed everything, so would have to find that connection and make a change. I'm assuming that if I ran but one 120 lead from the bigger generator I wouldn't have available the full amp capacity of the bigger generator. Is my general reasoning right??

Do any of your Califonians have the bigger generators with the 220 or the two 120 leads wired into it? Suspect it wasn't a 220 bus if you have the 220 capability, but rather two 120 circuits from the generator.

I'm only going to have $500 dollars plus my old generator invested since my mechanic took the generator as payment for work done and planned to put it on his boat. It wouldn't fit so he wants a smaller generator like mine for his boat.

I have one Westerbeke with 15 KW and other Gen Westerbeke with 8 KW. Two Gens are with 220 Volt. My air goes with 220 Volt el rest with two lines with 110 Volt. This installation is normal on many boats.
 
I will hire an expert, but the more I know, the more I can judge how expert the expert is.

Will probably add a second air cond. but will be one to plug in off the existing house circuit. Not inclinded to go with the standard water cooled system but a portable or hatch mount.



Supertramp it sounds as if the smaller generator with the two 110 lines may be subject to the unbalanced load that was discussed in the previous post. Is that the situation?? And is that a problem for your system? Thanks
 
I will hire an expert, but the more I know, the more I can judge how expert the expert is.


Supertramp it sounds as if the smaller generator with the two 110 lines may be subject to the unbalanced load that was discussed in the previous post. Is that the situation?? And is that a problem for your system? Thanks

Yes it is correct you need a good calculation with the two lines and the grand consum for the air are en 220 Volt in my case.
In my case i used the 8 KW for " nightgen ".
 
generator swap

Attached is a drawing I found with the boat from Westerbeke. It seems to suggest the 4 wire gen. can be used to just supply a single 120 volt lead to the boat, but not sure how that is done. In the three wire 220 system G1 and G4 are both hot 120 volts, but in the top drawing for the plain two wire lead to the boat's 120 volt system it shows only one lead hot. ???
 

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There are 2 output windings on the stator, for 120/240v they are in series with the center grounded which becomes the neutral(white) and ground(green). For 120v the windings are in parallel with one end grounded which becomes the neutral and ground. This is done by changing the taps on the connection board in the back end. Be carefull not to let the smoke out!
 
Talked with Westerbeke dealer and his gen. expert. They both said the top drawing would work, just had to find the right wires to connect. G1 and G3 are still labeled. They showed me how to remove the end cap and showed me G1,2,3 and 4 and said just run continuity with VOM to find the G2 and G4 and double check G1 and G3 to make sure they were labeled correctly. Think I have it figured out. Thanks for the suggestions.
 
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