ok guys got another question for ya... so we capitalised on black friday deals and got a load of stuff for our van. one of these things was a hot water heater. however, since my partner and i worry about having propane in an enclosed environment, it is electric. it has an 1800W draw, so we prepared for a 3600W surge at startup. What i mean when i say prepared is: We have an AIMS 3000W inverter with surge capabilities to 9000W. its an Inverter/Charger, and its the more expensive UL rated one. My question is, what wire gauge should i use for the inverter? when i went to calculate using blue sea's wire wizard thingy, it told me a 0 gauge wire and a 250A fuse. kinda worried about that since that is bigger than the 4AWG i plan on using for my solenoid to house battery, and battery to battery parallel hookup... any input is, as always, very appreciated.
Inverter wiring / hot water heater
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highdesertranger
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well let me see first off heating coils really don't have a start up surge. second what are you planning on using for batteries 1800 watts through an inverter to heat water is a huge draw on your batteries. that's like 150 amps without counting the inefficiency of the inverter I would like to point out that heating anything with electricity is very inefficient, you just don't notice it on the grid because electricity is so cheap. highdesertranger
If you pull that much power from batteries it has to be replaced using a large solar array and/or shore power or generator.
If that water heater has a standard heating element, you should consider getting a 12v element for it, and reducing the wattage to something under 700 watts or so, mainly due to wiring size.
At least then you wont have inverter loss to consider.
If your batteries are a long distance from the water heater, then stick with 120v elements with inverter AC line spanning that long distance, but again, consider buying an element of lower wattage.
If that water heater has a standard heating element, you should consider getting a 12v element for it, and reducing the wattage to something under 700 watts or so, mainly due to wiring size.
At least then you wont have inverter loss to consider.
If your batteries are a long distance from the water heater, then stick with 120v elements with inverter AC line spanning that long distance, but again, consider buying an element of lower wattage.
Seminole Wind
Well-known member
this is really getting disappointing, this is not the first time someone has come and asked a specific question.( in this case about wire size for a particular installation). yet all you guys ignore the question and tell him he is doing it wrong and give all sorts of answers and solutions to questions that were never asked. all the while never addressing the original question.
what happened to this site
what happened to this site
The OP already has the information about the wire size needed.
Then the OP asked for 'any input'...infering that they need advice about this setup.
That's exactly what was offered.
Then the OP asked for 'any input'...infering that they need advice about this setup.
That's exactly what was offered.
Zil
Well-known member
Uh? Hey, Weight, go have some coffee and a snickers.
Is this an on-demand water heater, or a constant draw type ? Is there enough room to house the solar panels needed for such a high draw item like an electric water heater ? I think a much better path would be to have a propane unit, or heat the water on a propane stove in a pan as needed.
I'll leave to those more knowledgeable than I be the final word but in calculating my starter batteries (2) to house bank (200ah) via ML-ACR 500 isolating circuit it called for 00 gauge, run of about 30 ft total circuit. That's in order for option of using house bank for emergency start and using 300 amp fuse, iirc.
gsfish said:
i have 2- 120Ah deep cycle batteries, the batteries and inverter will be in a compartment with my Blue Sea fuse block, i dont anticipate using the water heater much, it is an on-demand system mostly for doing dishes, and showering. the house batteries are going to be charged on a 200A continuous duty solenoid. as for the inverter instructions, im not totally clear on what you mean.... thanks guy
highdesertranger
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ain't going to work. you only have 120Ah of useable battery and you are going to put a 160amp load on it. then you are going to recharge it off the alternator. do you realize it is going to take 6+ hours of driving at highway speed to recharge the batteries, idling won't cut it. highdesertranger
The wire size from your alternator to your solenoid and solenoid to house batteries should be sized for distance and amp size of your alternators output. The solenoid provides for a one-way transfer of power from alternator to batteries.
Power from batteries to inverter should be sized for distance and maximum draw from inverter ( this maximum can be the total draw of ALL your needs and not the total output of your inverter as long as it is less ). You have a 3000/9000 watt inverter but if your total needs (now AND in the future) are only (example) 2800 watts, then that is what you size for. Multiple batteries must use the same size (larger is better) wire to interconnect all of them. Remember your total draw is being pulled through all your batteries.
Inverters wired to multiple batteries should use the closest positive post and farthest negative post to connect the inverter to insure power is drawn through all the battery pack.
example.... http://1948model.blogspot.com/2010/08/my-battery-pack.html
Power from batteries to inverter should be sized for distance and maximum draw from inverter ( this maximum can be the total draw of ALL your needs and not the total output of your inverter as long as it is less ). You have a 3000/9000 watt inverter but if your total needs (now AND in the future) are only (example) 2800 watts, then that is what you size for. Multiple batteries must use the same size (larger is better) wire to interconnect all of them. Remember your total draw is being pulled through all your batteries.
Inverters wired to multiple batteries should use the closest positive post and farthest negative post to connect the inverter to insure power is drawn through all the battery pack.
example.... http://1948model.blogspot.com/2010/08/my-battery-pack.html
Anhedonic
Well-known member
I've been considering an electric on-demand water heater for my van, but I took one look at the specs and asked my GF of she was OK with only having hot water when the engine or the generator are running to generate the power for it. The amount of power it takes to heat water is enormous. I don't think you will get a full shower out of those 2 120ah batteries.
I can't address wire gauge issues as I just don't know.
I can't address wire gauge issues as I just don't know.
