Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×

Thread Tools Display Modes
Old 02-26-2017, 12:07 PM   #1
Join Date: Feb 2017
Location: Northern Virginia
Posts: 55
Year: 2005
Coachwork: Thomas
Chassis: Frieghtliner
Engine: 210hp Mercedes Benz Diesel
Rated Cap: 71 person
designing my power system

I'm moving on from the structural modification planning phase of my bus conversion and have questions about what is the best etc power design for me.

I'm considering quiet Honda generator power (maybe 2) for most everything I need but would like a limited shore power capability (perhaps a limited receptacle circuit), and some 12V power for limited lighting, my water tank pump, etc. But my travels will for the most part be away from all sources of power, hence the generator option as primary.

I do not want to get into solar - my trips are 2-3 days at a time, maybe a few weeks at a time occasionally, storing the bus in a farm barn when not in use, and I am not living in the bus. I really want a simple, straightforward design and upkeep system.

Will need to power AC/Heater, small 1/2 sized refer, receptacle circuits, small microwave, hot water heater, flat screen, and a circuit for AV equipment - nothing heavy.

what are you experienced electricians thinking?

05FrieghtlinerThomas is offline   Reply With Quote
Old 02-26-2017, 12:38 PM   #2
Bus Crazy
turf's Avatar
Join Date: Apr 2013
Location: Colorado
Posts: 1,689
Year: 1993
Coachwork: bluebird
Engine: 5.9 Cummins, Allison AT1545
Rated Cap: 2
i'm not an electrician, but i am experienced.

my bus was an old bookmobile, so it came with a huge generator and no shore power. the generator is 12kw diesel, plumbed into the bus fuel tank.

most of my bus(house) is 12v. the heater, the fridge, the lights, waterpump all run on 12v. the house has a battery bank of 4 - 110 AH and that gets me by 1 day.
the 120 and 240 volt stuff in my bus are the 2 Air conditioners (120v), the 2 electric heaters (240v), my kitchen stove (240), my water heater(120), and my battery charger(120).

i need to run my generator 2-4 hours a day to charge the batteries. Or i can plug my battery charger into any 15A shore line.

i am just finishing adding a 50a shore line and transfer switch so that i'll be able to do without the gen in a campground and plug in for my appliances.

so with all that said, i'd size a generator for as many air conditioners or heaters you will run. they are your biggest load.

imo you need about 4-5 kw to run an older AC. i think my gen is perfect at 12kw, because it gives me enough power to run 2 ACs and my kitchen stove at the same time.

size your battery bank for how often you want to run the generator. bigger banks take longer charging. spending the money on good batteries will cut charging time.

my generator only system has worked well, i need to run it to cook. so an hour in the am and 1 in the evening fits my eating schedule and keeps the batteries up for the day.
it doesnt work well at a campground when power is available. i still have to run the generator and i usually have close neighbors. this is why i've just added the 50a shore line, to plug in when i can.

good luck
Turfmobile Build Thread
turf is offline   Reply With Quote
Old 02-27-2017, 09:51 AM   #3
Bus Crazy
Join Date: Jun 2013
Location: Picton,Ont, Can.
Posts: 1,956
Year: 1997
Coachwork: Bluebird
Chassis: GMC
Engine: Cat 3116
Rated Cap: 72
I did a simple wiring job on the ac side and used the 12v batteries also. I built a box for a generator on the back bumper passenger side. From the gen box I ran a 10/4 cabtire thru the bus wall and into a 30A disconnect which happened to be three phase. So, I used the red wire to feed the line side and just jumpered to the other line terminals. That gave me 3 hot circuits out to a 3 gang switchbox like you would have in house lighting for example.
One switch controls the back area of the bus for lights, fan a/c etc. The second switch I took directly to the water heater I have which is also a small 1500 element. The third switch feeds the front of the bus and can run my a/c, microwave, dual hotplate, battery charger and block heater.
In doing this I can manage quite well for now with this being a camper but may turn out full time later on. All the comforts really with minimal inconvenience. I have a bigger generator about 6.5 kw but chose to go with only a 2500 W genny for now. Works great and can be plugged into a normal 30 A campground outlet. This uses way less gas and makes less noise and can be on going down the road. It runs about 6 hours on a tank of gas and I have a larger stainless tank from a boat to mount underneath for a larger supply of gas when I really want to go off grid.
Planning on being outdoors, not so much in the bus so this worked for me.
#10 wire is good for 30 amps but I have it fused at 15 where needed on each switchleg.
Question everything!
BlackJohn is offline   Reply With Quote
Old 02-27-2017, 11:27 AM   #4
Bus Crazy
Join Date: Feb 2012
Location: Salt Lake City Utah
Posts: 1,635
Year: 2000
Chassis: Blue Bird
Engine: ISC 8.3
There are a few decision points that once resolved can help to bring the big parts of the design into focus.
  • Do you require 240 volts for any appliance?
  • Is generator noise a concern, either for yourself or for neighbors in a campground?
  • Which loads do you want to be able to run at any time, day or night, out in the sticks or in a crowded campground? These are the loads that may need to be available without starting the generator, ie to run from battery power.
  • Is the heater 100% electric, or is it burning a fuel for heat and using the electricity only for control and the air blower?
  • Which loads need to run simultaneously from the battery? the inverter? the generator?
The answers to those will help draw a box around the type and size of battery bank, inverter, and generator that will meet your needs and wants.
family wagon is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 05:54 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.