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Old 12-07-2015, 15:53   #1
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What size generator?

Hello! New member and boater here. I have a 38' 1989 Trojan tri cabin and I need a generator that will run 2 mini fridges, a/c, lights, radio/satellite TV, ice maker and maybe a couple of phone chargers simultaneously. And occasionally in addition to all of that a cook top, microwave, coffee pot or blender. I was thinking 42-43 kW but from what I've been reading that may be a bit much. I don't want to over load the generator but I also don't want to have double the power needed. Please help. Amy advice will be appreciated.
Ps. I'm in the USA.
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Old 12-07-2015, 17:28   #2
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Re: What size generator?

Each appliance has a power demand specification. As no one here knows precisely what each spec is, rather than rely on uninformed opinion,you should determine what the needs of each is. Simple addition and a bit of contemplation regarding which might be used simultaneously will give you a better answer than us.

Having said that, my wild guess is 42 kW is WAY too big. We have needs comparable to what you described and our 12 kW genet is more than adequate.
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Old 12-07-2015, 17:57   #3
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Re: What size generator?

What sort of shore power setup do you have, and is enough power for you?


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Old 12-07-2015, 18:03   #4
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Re: What size generator?

42 kw ?

As usual the mods prove themselves to be useless.
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Old 12-07-2015, 19:32   #5
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Re: What size generator?

I was using this website Selecting the right size generator | Beta Marine Pacific NorthwestBeta Marine Pacific Northwest to calculate the amounts and that's how I got such a large number.
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Old 12-07-2015, 19:43   #6
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Re: What size generator?

Quote:
Originally Posted by Sailmonkey View Post
What sort of shore power setup do you have, and is enough power for you?


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I have adequate shore power. The generator is for when out on the water.
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Old 12-07-2015, 19:47   #7
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Re: What size generator?

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42 kw ?

As usual the mods prove themselves to be useless.
I was using this website Selecting the right size generator | Beta Marine Pacific NorthwestBeta Marine Pacific Northwest and that's how I got to such a large number.
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Old 12-07-2015, 19:48   #8
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Re: What size generator?

I'm a do it your self kind of guy but with these questions you really would be way ahead to consult a pro. My guess is somewhere between 5 and 12 kw. But that is a really big spread both in size and money.
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Old 12-07-2015, 19:51   #9
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Re: What size generator?

Any suggestions on a pro in the Tennessee area that would be reliable and honest and not charge an arm and a leg?
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Old 12-07-2015, 19:53   #10
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Re: What size generator?

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I have adequate shore power. The generator is for when out on the water.

I'm aware of that. But if you have a single 50amp shore cord and that is sufficient power then you can use that to estimate the generator size.


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Old 12-07-2015, 19:58   #11
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Re: What size generator?

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Any suggestions on a pro in the Tennessee area that would be reliable and honest and not charge an arm and a leg?
A 42KW Generator will cost a lot more than an arm and a leg
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Old 12-07-2015, 20:01   #12
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Re: What size generator?

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A 42KW Generator will cost a lot more than an arm and a leg

And would be larger than the propulsion engines on a 38' boat!


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Old 12-07-2015, 20:26   #13
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Re: What size generator?

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And would be larger than the propulsion engines on a 38' boat!
A 38' Trojan probably has twin V-8 engines each of which will be well over 100kW.

Assuming the OP isn't kidding the answer is you need a generator capable of about 7.5kW. You could probably get by with 6.5kW (50A) but 7.5kW would give some margin.
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Old 12-07-2015, 20:33   #14
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Re: What size generator?

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A 38' Trojan probably has twin V-8 engines each of which will be well over 100kW.



Assuming the OP isn't kidding the answer is you need a generator capable of about 7.5kW. You could probably get by with 6.5kW (50A) but 7.5kW would give some margin.

I meant in physical dimension.


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Old 12-07-2015, 21:40   #15
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Re: What size generator?

If your 50A shore power setup allows adequate capacity, there is nothing to be gained by grossly exceeding that figure in a genset.

I would select a unit that would provide the required 50A at roughly 80% of maximum generator output. Say 7.5kw?
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