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RV inverter to 240v consumer help please

Krvmum

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Jun 7, 2020
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I got the mppt tracer 40 solar charger. I'm setting it up in my RV now. I have a 4000w inverter but I'm not sure what wire/cable size to use from that to the original fitted 240v consumer unit. I want to power the original electrics. (Without wire melting)
 
4000/240 = ~16.6 amps. Even if you don't draw 4000 watts you need to work on the basis that your inverter can supply it. If you use lighter wire you need to protect it with a breaker between it and the inverter. By UK standards (I'm assuming UK from you saying consumer unit), you'd want at least 4mm for cabling inside an insulated wall cavity. Note the date on that web site, the UK likes to regularly fiddle with its standards, so this may well have changed.

 
Ok thanks. I'll calculate it. Thinking a bigger cable than 4mm tho? 4000-12000 inverter. RV has a washing machine, coffee maker and disability aids and scooter to power.
 
If you are looking at 12kW you are going to need some serious wiring and a decent consumer unit too. That's about 50 amps. What's your DC voltage to the inverter?
 
I'm new to this and not sure of calculations.
I've got 2x 275w solar panels going to a tracer mppt 40. To the 4000/12000 inverter. Then to 2x 140amp batteries in 24v.
I want to power the RV's original consumer unit for 240v.
 

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140AH 24V is likely going to be running hard to produce 4000 watts (166 amps from a 140AH battery) unless you buy a real premium battery. 12000 isn't going to happen. You'll need to think about your actual worst case load and then size the battery to be able to handle that.

If you don't have one, get a watt meter (example only) and start monitoring to work out how many kilowatt/hours (kWh) you use across a full day, the peak draw and for how long you will have to hold that peak up. These types of meters usually won't bear 4000 watts either, so you'll have to test items separately and add things up. You can find a guide about working out what you need in terms of power in the forum FAQ section, this will give you some pointers but don't be afraid to ask for more advice.

 
I plan on adding another 2 batteries at least. I will be running the generator for the washing machine (0.95kwh per cycle) then, think that's best option. The rest is a tassimo coffee machine (1300w), laptop charger, tv (45w) mobile phones etc.
 
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