# Does an inverter draw power if connected but switched off ??



## Mrplodd (Mar 4, 2008)

Title says it all really.

If I leave my inverter connected to my leisure battery bank but switch it off (so nothing is drawing from it) does it still draw any power, or is it like a light bulb?? (switched off draws no current) 

I am pretty certain I know the answer BUT its always best to ask. 

(I bet Clive MGTB knows !!!)


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## CliveMott (Mar 10, 2008)

The ON/OFF switch on an inverter of any significant size does not switch the supply to the inverter directly, it mearly turns off the electronics that run the power transistors inside the inverter. So the answer to your question is NO. But make sure that if you leave it permanently connected that you have appropriate fusing between the inverter and your battery - just in case something causes a voltage spike and the power transistors fall over and start taking current, LOTS of current!.

Some BIG inverters have a power relay as a remote ON / OFF switch and this is safer but adds to the quiescent current taken by the inverter when turned ON..

Chive.


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## Mrplodd (Mar 4, 2008)

Thanks Clive, thats pretty much as I thought.

My plan now is to fit a battery isolator switch INSIDE the MH in the live feed so I can switch the inverter on (and off) without having to venture outside on hands and knees and firtle in the low slung locker every time I need a fix of Top Gear !!


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## Glandwr (Jun 12, 2006)

CliveMott said:


> The ON/OFF switch on an inverter of any ..... when turned ON..
> Chive.


Beware Mr Plod he's an imposter, one of the onion mob!


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## wackywyco (Apr 30, 2007)

Is that why, when I connect my(switched off) invertor to the battery
using the crocodile clips I get a spark when coupling the earth side up? I was always led to believe you only get the spark if something was turned on. (As when you connect a car battery)


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## CliveMott (Mar 10, 2008)

Yup,
The inverter will have a large capacitor connected across its input and its the inrush current into this that causes the spark on the croc clip.


Chive, At last someone noticed! Perhaps I am apealing or perhaps I make people cry!!

C.


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