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Topic: installing a house electrical system (Read 7 times) previous topic - next topic
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installing a house electrical system
Yahoo Message Number: 110704
Andy,
 I know this has been talked about before many times on many different groups, but there are still some things I have a problem wrapping my head around as to what's best among the many choices I have found searching on the net. So again I ask please for your help.
 My situation. I like the Lazy Dazer group and I realize my situation only is similar in that I will be living in a van (yes I know, down by the river) in a few months. I have the money to make changes now as I have a full time job, but after a few months I don't have definite answers as to what my situation will be.
 Please help with me a paint-by-the-numbers setup. I know at a high level what I want to do and at a low level, once the decisions are made, I don't think I'll have any problems doing the installation.
 Ok, so what I have and what I'm thinking. I have a Chevy Express 3/4 tonne vehicle that in a previous life was a delivery vehicle. I'm thinking to run wires from the alternator through a continuous duty solenoid to house batteries, from house batteries to a pure sine wave inverter for my laptop, LED lights, vents, fans, and various battery chargers, oh and scanners and external hard drives used from my laptop. On the primary charging line will be large (to me) switches and fuses to interrupt the charge current. If I have a 100 amp alternator, do I use the normal AWG wire sizing tables for calculating the size of wire between the solenoid and batteries?
 Solar. I have limited space on the roof of my van. I've been thinking of getting two of the largest panels from http://sunelec.com That should be right around 400 watts of generated power. Since I have limited space I am also thinking of using a MPPT solar controller for charging the batteries. The controller from Morning Star that runs between $160 - $250 only handles 15 amps. Seems to me the two panels are more than 15 amps. Which controller would be best for running two panels? I intend to mount the panels with screws through the roof if I get the panels before I build the interior of my van. Otherwise I'll use the VHB tape.
 I also intend to have a fantastic vent in the rear powered by the house batteries to help provide cross ventilation inside the van.
 Batteries. I am thinking either four batteries or two 4D batteries. The Trojan T-105 batteries are talked about being 'the best'. With these batteries I want to mount there to the frame rails under the van. I have not found any ready made battery boxes. Next I'm thinking of keeping the batteries inside the van. The batteries inside the van would have milder conditions and temperatures to deal with, and that should extend their useful life. Batteries inside the van need to be AGM unless I build a custom battery box and vent that box through a wheel well. If I build a custom battery box how do I build it and what do I line it with.
 Number and types of batteries. So I'm thinking either four T-105, four group 31 something AGM, or two 4D wet or AGM. I know the battery cables between the batteries and inverter need to be huge.
 Inverter. I'm thinking between 600 watts and 800 watts. Something large enough to run a rice cooker (350 watts) and a few corded power tools (I already have these. If buying new I would buy the cordless type tools.)

If I can draw this what I think I have is:

X
X
+ alternator   solenoid    | X batteries |

X
X
+-----X 12V buss and items 120v items   inverter    | +-----X
X solar controller      solar panels
 The picture looks like I've simplified too much. What did I leave out? Also, the wire that connects the solenoid to battery to inverter to solar controller though maybe of different sizes looks to be just a buss for those items.
 Between the solenoid and batteries (under the van or inside the van) I expect to run the charge wire through PVC type conduit. I expect to run both positive and negative wires and not use the van frame as a negative ground.
 The AGM batteries are $1,000, the solar panels are $1,000, probably $300 for the inverter, and another $300 for wires and connectors. I should be able to put in a solar electrical system in my van for under $3,000. That sounds like a lot of money. Is my perception just skewed?
 Does this make sense? Have I forgotten something? Do you have specific suggestions of what to buy (one 2000E controller, one Xantrex inverter model, two polycrystalline panels for $500 each, two 4D AGM batteries model).
 I realize I'm asking a lot and I also realize you don't work for these companies, this is not your business, and that you help me out. If I'm asking too much tell me and I'll figure this out myself. I just don't want to do this twice. I want to do it right the first time.

Thanks for reading this.

a9
 
Re: installing a house electrical system
Reply #1 –
Yahoo Message Number: 110713
"If I have a 100 amp alternator, do I use the normal AWG wire sizing tables for calculating the size of wire between the solenoid and batteries?"

a9  (an odd name)
 You will never have a 100-amps available for the batteries due to the demand of the engines and accessories but you might want to wire for such in case you upgrade to a bigger alternator in the future.
Here is a wiring chart I use.
http://www.westmarine.com/webapp/wcs/stores/servlet/westadvisor/10001/-1/10001/Marine-Wire.htm> Use the 3% drop table and consider upgrading a wire size or two. Big wires make a big difference when dealing with high amps and 12-volts.

"Which controller would be best for running two panels?
 A Heliotrope's HPV-22B MPPT Solar Charge controller is rated to handle up to 400-watts.
http://www.amsolar.com/hpv22.html>
 4 T-105s will need a custom built rack to hold it under the frame, which will add hundreds to the cost unless you can do it yourself.
http://www.flickr.com/photos/lwade/1416466406/in/set-72157602104740457/>
http://www.flickr.com/photos/lwade/sets/72157602104740457/> An external battery pack would not use any valuable interior space. T-105s are much cheaper than AGMs.
AGMS can be put under a seat or in a plywood box.  AGMS can be mounted inside if they are contained by a frame, bolted through the floor, to keep them in place during an accident or rollover.
For your needs, I agree that 4 T-105s, or the equivalent in AGMs, are going to be needed.
 I recommend a battery meter for tracking power consumption and generation.
http://www.xantrex.com/web/id/273/p/1/pt/5/product.asp>
 A marine battery switch is suggested and you can run a jumper to the starter enabling jump-starting just by turning a switch.
http://www.flickr.com/photos/lwade/1415588249/in/set-72157602104740457/> You will a large `catastrophe' fuse at or very near the new coach battery.
Here is a new type I'm interested in trying.
http://tinyurl.com/yhlczj5>

Pure-sine-wave inverters are expensive so make sure you need one.
You may be able to use a small pure-sine inverter for just the sensitive items and use anther, larger modified-sine-wave inverter for the things that do not need a pure wave.
 "Between the solenoid and batteries (under the van or inside the van) I expect to run the charge wire through PVC type conduit. I expect to run both positive and negative wires and not use the van frame as a negative ground."
 Running ground wires is nice touch but you might as well ground the coach battery to the frame anyway, it needs a pathway back to the alternator, which is grounded to the frame.

It is a lot of money. Welcome to RVing!

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)