Inverter cabling

[Neil S]

I’ve ordered an inverter sterling pro 1600 watt pure sine wave but the cabling is only 50cm long
Just a bit to short as I need 70cm ish
Going to order some replacement longer but I’m unsure as to what mm of cabling I need to cope with the load of approximately 1200 watts
Can someone advise

 

[autorouter]

I think 10mm sq would be OK, giving a drop of 2.13% for 700mm pos and neg wires. The guideline is to keep the voltage drop below 3%. The amps requirement for 1200W at 12V is 1200 / 12 = 100A.

For 500mm lengths 6mm sq gives 2.62%, which is fine, but extending that to 700mm gives 3.67% which is just over the 3% guideline. Not a big deal, but if you're buying new you might as well buy the thicker wire. There are several online calculators that you can use for this, I tend to use this one:

Voltage Drop Calculator | 12 Volt Planet

Use our Voltage Drop Calculator to select the correct Cable for your campervan, motorhome or boat wiring application. Auto and Marine Electrical Components from 12 Volt Planet - Cable Size Calculator

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[I2C]

Additional to autorouter ’s link, here’s one I use to see what cable sizing I should use for the amps over distance travelled.

 

[bigtwin]

The amps requirement for 1200W at 12V is 1200 / 12 = 100A.

True, but I’d size for the full rating of the inverter and divide by 10 (to account for inefficiencies) giving a current of 160A.

This would suggest that 16mm2 might be better?

Ian

 

[Stealaway]

I would also fit a battery isolator switch so you can turn the inverter off.

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[Neil S]

I would also fit a battery isolator switch so you can turn the inverter off.

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Will do