Inverter installation

Branchie · Senior Member

Inverter installation

yobarr · Guru

Branchie wrote:
Hi techies out there... I am looking at installing a 2600w inverter in the caravan. It will be mounted around 1mtr from the batteries. Just wondering if anyone out there, can give an approximate time on fully installation, wiring etc... I know its a big question... but just need an approximate as I dont want to be ripped off....

Hi Kevin. PM sent. Cheers

-- Edited by yobarr on Tuesday 4th of May 2021 06:26:11 AM

Colin Penrose · Senior Member

Hi. I installed my own about 300mm from battery in about half an hour. I used 6 B&S cable direct to battery. Simple job.

Are We Lost · Guru

2600 watts is a pretty big inverter for a caravan. What size battery bank do you have and what is the intended use?

The voltage drop will be quite substantial unless you have quite a large battery bank.

Whenarewethere · Guru

2600 watts, so probably about 3.0kVA. 1 metre, so that's 2.0 metres + & -

250 amps:

4awg 3.0% loss

2awg 1.9% loss

1awg 1.5% loss

Are We Lost · Guru

My comment about voltage drop was more about the battery's capability to supply voltage for more than a brief period, rather than the loss in the cable.

When I connect my 60 amp tyre pump to the single battery it very quickly drops below 12 volts. At 250 amps I would expect that to be almost instantly.

Whenarewethere · Guru

I use a 4awg cable for my 3 compressors which use up to about a 100amps. The compressors only start using their maximum rated amps when the compressor is at its maximum pressure. In general the compressor is using about 3/4 of its rated amps.

Clamp meters are very handy for measuring all the stuff.

Hylife · Guru

Possible but massively excessive without hugely thick wires and hundreds of amp hours of batteries.

The maths if you try to use the full inverters full capacity is as follows:-

(watts divided by ac volts) X (AC volts divided by DC volts) + 15% inverter inefficiency

2600 /240 = 10.8amps X 240 / 12 =20 + 15%

= (10.8 X 20) +15%

= 216 + 32

= 248

HELL YEAH! lets try and draw down 250 amps from my batteries!

Two 120AH AGM batteries will be at the recommended maximum depth of discharge inside of half an hour!

As for tyre pumps, a cheapy 150watt inverter will run my Stanley 0.5hp compressor that draws between 97 and 125 watts and is capable of 14L/min and 115psi.

ac6511-stanley-0-5hp-5l-oil-free-air-com

-- Edited by Hylife on Thursday 6th of May 2021 10:49:15 PM

-- Edited by Hylife on Thursday 6th of May 2021 10:51:40 PM

Whenarewethere · Guru

How many L/m at 90psi does the Stanley compressor do?

My setup is 261L/m free air delivery or more importantly 126L/m at 90psi, less air line, after cooler, drier & connectors inefficiencies. In other words 35 seconds per tyre about 65L volume from 20 to 35psi. The compressors are a bit ahead of what can be pushed through the valve.

I normally use it with the engine running. Alternatively I can run it off my 4 auxiliary batteries which can do 376amps (maximum) for 5 minutes or 100amp for 30 minutes.

If you draw a very large load the batteries have a smaller capacity than a smaller load over a longer period for the same overall watt/hours.

So if one is drawing 250amps off 2 batteries (125amps per battery), it's going to be painful for the batteries.

mark and kerry · Veteran Member

i was told about invertor parameters that 1 amp = 10 watts of load i thought it might help

Whenarewethere · Guru

What does 1 amp relate to?

Jaahn · Guru

mark and kerry wrote:
i was told about invertor parameters that 1 amp = 10 watts of load i thought it might help

Hmm Yes it is a quick rule of thumb. Putting it around the other way, aww if you want 10Watts then the inverter will draw 1 amp. Around about close enough !

So if you want 1000 watts it will draw 100 amps

If you watts 2600Watts then it will draw 260Amps. Close to Hylife's figures. hmm

It sure is a big discharge from your batteries that you would want to limit time wise.

Jaahn

Whenarewethere · Guru

The quicker one draws a battery down the smaller capacity it has.

My batteries

20 hour rate 26AH

10 hour rate 21AH

5 hour rate 19AH

1 hour rate 14AH

So one may have 240AH of batteries, but drawing 260amps & your batteries are effectively only 120AH.

If one can keep the load less but over a longer period your batteries will be a lot happier.

Chuck out the 2200 watt kettle & replace it with a 750 watt kettle from Birko for example.

& if possible do the heavy load stuff while there is solar input. Boil water in the middle of the day & put it in a Thermos flask for the evening.

Rusty W · Veteran Member

Just because Branchie is fitting a 2600 watt inverter doesn't mean he will use it to it's maximum. I have a 2500 watt inverter and it's main use is a 600 watt microwave. Sure it will run the A/c and the hot water system at the same time, but i don't. Sometimes I will run the ho****er system for 5 to 10 minutes just to top up a bit of heat but only when I know the solar or motors will put the power back in. Overkill ? sure but the inverter just idles along, but the extra power is there if i ever need it.
regards russell

Dicko1 · Senior Member

Rusty W wrote:
Just because Branchie is fitting a 2600 watt inverter doesn't mean he will use it to it's maximum. I have a 2500 watt inverter and it's main use is a 600 watt microwave. Sure it will run the A/c and the hot water system at the same time, but i don't. Sometimes I will run the ho****er system for 5 to 10 minutes just to top up a bit of heat but only when I know the solar or motors will put the power back in. Overkill ? sure but the inverter just idles along, but the extra power is there if i ever need it.
regards russell

Totally agree. Also for all we know he may have 4 x 120 ah lithium batteries that will handle the inverters full power easily. Original poster has not stated his battery type or Ah capacity .,,,this info would help.