Inverter reverse current

I'm guessing that you have something live touching metal but then I'm not a sparky!

Kind regards

Can't help with the problem, but I just keep getting and image of Homer Simpson in my mind.

Zap...DOH!

Zap...DOH!

Zap...DOH!

Troll -

Suggest first, satisfy yourself it's not just a static electric bite - the sort of zap we all get occassionaly by sliding out of a vehicle then touching the vehicle.

If you're convinced it's coming from the inverter, talk to an electrician (not an autoelectrician, a mains type person.)

To get a shock from mains voltages such as your inverter produces, electric current must flow through you. One side of the 240V mains supply is connected to ground, so many electric shocks result from standing on the ground and somehow coming in contact with the other side of the mains supply.

With an inverter though, there isn't any obvious connection to the ground, so standing on the ground and touching the vehicle shouldn't result in any current flowing through you, so no shock. Get someone with a suitable meter and knowhow to make a few measurements.

When dealing with mains voltages, if in any doubt, touch with the back of your hand fiirst, not the front - that way if it is dangerous you'll jump away, not have your hand forced closed to grip it tighter. Better still - let someone else do it!

HTH

John

Is it -

1. A (cheap) modified sinewave

2. Got a windnut on the back with the 'earth' symbol

There has been quite a bit of discussion about the safety aspect of cheap (what most people buy) inverters. I hope this thread does not die, I'm looking forward to what the cause off your problem is.

It sounds like there is a short between the 240v Active and the 12v Negative inside the inverter, thus causing the vehicle to become live and anything else that is connected to the battery (your fridge)

WITHOUT POWERING UP THE UNIT you can prove this by using an ohm meter to measure the resistance between the Active pin on the inverter (left hand side as u look at the 3 pin outlet) and the negative terminal.
Shoul read a low resistance if my hunch is right.


PLEASE, DO NOT PUT POWER ON THE UNIT UNTIL YOU HAVE HAD IT CHECKED BY SOMEONE QUALIFIED

You almost certainly have an inverter that does NOT have the secondary winding (the 240 volt one) isolated from the primary (the 12 volt one). Unfortunately most of the older inverters were like this, and unless it clearly states that it is isolated (all the recent Jaycar ones are) it almost certainly is not. In effect these have a single winding, tapped at one end for 12 volts. These are potentially dangerous and in my view should not be sold or used. They have recently been banned on Victorian worksites I understand, but should be banned everywhere.

You usually need to touch both an active and an inactive to get a big (usually lethal) belt, but the capacitance of your body canl cause a small current to flow and give you a tingle (or worse). My advice is to cut the leads off (so it cannot be used again) and throw it in the rubbish bin.

Regards avro

Being 7 years old it is possible that the primary winding in its transformer is also part of the secondary winding (called an auto transformer.) If one of the output leads had leakage to ground then the whole of the car could have been live.

Most of the newer inverters have the primary and secondary windings of their internal transformer isolated from each other. Always purchase inverters that have their 240V output electrically isolated from the 12V circuit. You can check if there is isolation with the ohms range on your multi meter. Disconnect the inverter from everything. If there is an input switch on it switch this on. Set the multi meter to a low ohms range and test to see if there is any resistance between either of the input leads and the output leads. If there is any resistance between an input lead and either of the output leads it is not an electrically isolated unit and should be thrown out or used with caution.

To see what an auto transformer is go to this link

PeterD

Troll 81 - guess you didn't want to see me at Gordon Country at the weekend if you had seriously fuzzy hair after the little zapp!!! LOL.Missed meeting up with you - there sure were plenty of people there. My kids had a great time - lucky I took my own lunch because the Sunday roast lamb did not eventuate.