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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Airbag on August 03, 2009, 10:37:01 PM

Title: Gen loading question
Post by: Airbag on August 03, 2009, 10:37:01 PM
I have an 8KW gen with two legs of 120V and right now have two roofs each hooked to one leg. Now if I wanted a third AC how would I go about it? I already had two hooked too one leg by mistake and it blows the breaker. Is there a way to tie to both legs to enable a third AC? Or am I asking too much from the gen.
Title: Re: Gen loading question
Post by: buswarrior on August 04, 2009, 12:39:24 AM
If you have no need for 240, I'd be inclined to wire a generator for straight 120.

That way, no balancing needed, and the whole 8K is available for use.

Seen so many installs where the full rating of the generator was inaccessible due to the breakers on one side or the other of 120/240 being tripped, if that makes sence.

happy coaching!
buswarrior



Title: Re: Gen loading question
Post by: JackConrad on August 04, 2009, 06:00:33 AM
As BusWarrior said, your generator can be wired for 120 only.  Tell us what make and model generator you have and someone on here can probably help you change your wiring to 120 volt only.  Jack
Title: Re: Gen loading question
Post by: Airbag on August 04, 2009, 06:42:19 AM
That does make sense guys, I will get the info. Thanks
Title: Re: Gen loading question
Post by: rv_safetyman on August 04, 2009, 07:15:22 AM
With 8KW you are going to have to watch your loads.  Not considering efficiency and loss at higher altitudes, you have a bit over 60 amps.  That sounds like plenty for 3 ACs (maybe 12 amps each), but if they all start at the same time, you will be maxed out.  Will also have to watch how much else you have on. 

If you have a good converter that charges the battery, you will probably have to set the "input" amperage pretty low if the batteries are low.  Coffee pots and micro-wave are big power hogs and you will probably have to manually manage the loads a bit when you use them.

Jim
Title: Re: Gen loading question
Post by: Airbag on August 04, 2009, 07:19:40 AM
Quote from: rv_safetyman on August 04, 2009, 07:15:22 AM
With 8KW you are going to have to watch your loads.  Not considering efficiency and loss at higher altitudes, you have a bit over 60 amps.  That sounds like plenty for 3 ACs (maybe 12 amps each), but if they all start at the same time, you will be maxed out.  Will also have to watch how much else you have on. 

If you have a good converter that charges the battery, you will probably have to set the "input" amperage pretty low if the batteries are low.  Coffee pots and micro-wave are big power hogs and you will probably have to manually manage the loads a bit when you use them.

Jim
Good point Jim. We don't use much power going down the road just the AC's.
Title: Re: Gen loading question
Post by: TomC on August 04, 2009, 07:27:45 AM
I have a 10kw Powertech that is wired straight 120vac and love (mindless-don't worry about loading).  I also have the bus wired straight 120vac-meaning I only use one leg of the 50 amp plug.  It has never been an issue as to tripping the circuit breaker, and love it so much, I'm wiring my truck with the Wrico 13kw straight 120vac also.  Good Luck, TomC
Title: Re: Gen loading question
Post by: Airbag on August 04, 2009, 09:55:50 AM
This is the info off the data plate.

Engine: Izuzu MOD 3LB1GA02
680 Spartan2 KC-D

Generator: Nor'Pro
MOD XC8KW0000N
4 wire
120/240
PF 1.0
1800 rpm

Regulator VR 2.4
Title: Re: Gen loading question
Post by: Len Silva on August 04, 2009, 11:44:18 AM
I couldn't find your exact model but here is the company  http://www.4norpro.com/index.html (http://www.4norpro.com/index.html)

It looks like they use Marathon generator heads, a very good product.  Contact them for reconfiguration info.  There should be a diagram somewhere in or on the generator, probably inside the connection box cover.
Title: Re: Gen loading question
Post by: Airbag on August 04, 2009, 02:44:31 PM
Quote from: Len Silva on August 04, 2009, 11:44:18 AM
I couldn't find your exact model but here is the company  http://www.4norpro.com/index.html (http://www.4norpro.com/index.html)

It looks like they use Marathon generator heads, a very good product.  Contact them for reconfiguration info.  There should be a diagram somewhere in or on the generator, probably inside the connection box cover.

How will this affect the rest of the wiring in the bus?
Title: Re: Gen loading question
Post by: gus on August 04, 2009, 03:36:41 PM
Rick,

I run two ACs and one frig from a 6kw Honda.

When I want to use the microwave I just turn off the frige for a few minutes.

You will have better luck if you turn on the ACs one at a time and wait quite a few minutes before turning on the third one.

If you can close off the bedroom or any part of the rear from the front you won't need more than two running down the road.

Then at night you won't need more than one AC after the sun goes down.

Sunshine on the Al exterior is the biggest problem. If you can, make the top white.
Title: Re: Gen loading question
Post by: buswarrior on August 05, 2009, 06:22:56 PM
How will this effect the bus wiring?

Depends how it is wired now...?

More than likely you have the coach split somehow into two parts, each on one hot leg from the generator.

Some choose to leave the coach "split" so that they may take advantage of 50 amp wiring when they find it, and have a system of combining both sides for generator and 30 amp use.

Switches, both manual or automatic, manual plugs, lots of options, hard to mess with this in writing.

happy coaching!
buswarrior
Title: Re: Gen loading question
Post by: Len Silva on August 06, 2009, 06:47:11 AM
The major concern would be the size of the wires from the generator, through the transfer and to the distribution panel.  You could combine the two hot leads and they would probably be adequate but the neutral might be too small.

If the wiring is all in conduit, it would be a simple matter to replace it.  If it's cable of some kind, it might be a little more challenging.

Len