Amp metre to Engle fridge

[LWEBB Lurker Find all posts View Profile Close LWEBB]

Hi I recently installed a cable down the side of the car from the dual battery to a new rear outlet (Engel plug).I connected it via an amp metre to moniter the amperage used. When the engine is not running the fridge is drawing around 2.5 amps steady, but when the engine is running the amperage flucturates from 0 - 2.5 amps constantly. With the new plug I have to remove the cigarete plug fitting which holds the dedicated special fusable link, I dont think this would cause this but not sure. Does anyone have any information for me as I have no idea as to what would be causing these fluctuations. Thank You.

[ozwapet2 Advanced Member Find all posts View Profile Close ozwapet2]

Re: Amp metre to Engle fridge

Hmmm .... a number of issues here and clarifications needed.
Firstly, you don't "draw" volts, you draw amps. If the meter says "volts" you have the wrong meter,
Secondly, an ammeter needs to be installed in series with the positive line, ( ie you cut the line and install the meter "in line") - have you wired it correctly ?
Thirdly, the 2.5 amps sounds about right for an Engel but it should not be "steady", it SHOULD only show that current draw when the fridge compressor is running ( you can hear when it is running ).
I think you've got a basic problem with the way you've wired things up.
Take some pics of your setup and post them, might help us to help you.
Also ,fill in your location details etc in your profile.

[LWEBB Lurker Find all posts View Profile Close LWEBB]

Re: Amp metre to Engle fridge

Hi Wayn, Yes it should be amps not volts,thanks for that correction I will blame the wife for that as she is not here and eddit the original post.
To post photoes is a bit of a problem at the moment but the amp metre is an 80 amp ABR sidewinder digital gauge and operates of a shunt connected in line.
The amp metre is connected between the aux. battery and the anderson plug on the rear of the car. I use this plug to supply to the caravan when towing.
The idea was to tap into the outlet of the shunt to also moniter the fridge power use.
I have a 50 amp fuse on the aux battery, then a 50 amp self reset circuit breaker, then the amp metre shunt and 8 gauge cable to the anderson plug.
The digital amp gauge power supply is supplied from the ignition switch for ilumination and operation.
The odd thing is that when the caravan is on it reads 12 -18 amps and steady as it is charging the van battery, but when it's the fridge only and the compressor is running, the amps flucturate until the correct temp. is reached then shuts down and the draw is "0".
I hope you can understand this as it is a bit long winded but any feedback would be appreciated.
Thank you.

[bdaearth Member Find all posts View Profile Close bdaearth]

Re: Amp metre to Engle fridge

well once the fridge is down to temp the compressor turns off so there is nothing to draw any power so thats the 0 reading as for the fluctuating amps on the way down I would think that is just how hard to compressor is working?

[ozwapet2 Advanced Member Find all posts View Profile Close ozwapet2]

Re: Amp metre to Engle fridge

Sounds all pretty much Ok to me too - I wouldn't worry about it, as long as the fridge is keeping your beer cold, relax.
Otherwise contact ABR Sidewinder -he's on this forum and is pretty helpful.

[LWEBB Lurker Find all posts View Profile Close LWEBB]

Re: Amp metre to Engle fridge

Thanks for the reply,
I feel that as you say everything is ok, but I am trying to understand why that when the engine is not running the fridge pulls a constant 2.5 amps whilst the compressor is operating, and when the car engine is running the amp metre fluctuates whilst the compressor is operating.
If I did not put this amp metre on I would not have a problem, but I have an ongoing electrical issue with the caravan (which no one hase been able to recterfy as yet) and want to moniter the electrical supply to the van but this introduces new issues like this.
Thank

[ozwapet2 Advanced Member Find all posts View Profile Close ozwapet2]

Re: Amp metre to Engle fridge

Ok ...if you current draw is fluctuating between 0-2.5 amps it suggests the supply voltage is not constant. ( switching on and off ). The Prado will vary the voltage when the engine is running, as it regulates the charging volts to the battery, but it should only vary a volt or so. What you need to do is put a volt meter ACROSS the line as well to see what the volts to the fridge are doing. ( you need to measure it somewhere near the fridge and with the fridge connected ). If you're getting constant volts there between 12.5 to 13.5 volts then I can't explain why the current would be varying.

[LWEBB Lurker Find all posts View Profile Close LWEBB]

Re: Amp metre to Engle fridge

Thanks wayne
It looks like I might have to visit an auto electrician to test it out.
All the best Laurie.

[Bert Junior Member Find all posts View Profile Close Bert]

Re: Amp metre to Engle fridge

long shot.1. suggest you try separate power supply to your digital amp gauge as it sounds like some operation conflict or 2. does your fridge have auto cut off if the voltage drops below a certain level? then again this doesn't explain why when engine off, it draws constant and not when on. got me stump. my 2 cents worth.

[Bert Junior Member Find all posts View Profile Close Bert]

Re: Amp metre to Engle fridge

is the verdict out on this?

cheers.

[LWEBB Lurker Find all posts View Profile Close LWEBB]

Re: Amp metre to Engle fridge

Hi bert
Yes the jury is still out and as I am still on the road I will wait untill I get home where I have more time and facilities to investigate more.
Thanks for your help and will post my findings once I work it out.
Mery christmas to all
Laurie

[LWEBB Lurker Find all posts View Profile Close LWEBB]

Re: Amp meter to Engle fridge

Hi
To all that are interested, I have conducted tests and found that when the engin is not running the 2.4 amps to the fridge match my installed digital gauge .
When the engin is running, my gauge is fluctuating and the indapendant gauge is stable at 2.4 amps.
This means that there is interference causing the meter to fluctuate.
I have a installed a relay on the power to the meter to try and isolate it, but this has not worked.
I will investigate other options but may have to live with this. At least I know there is no problem with the power supply which may damage my fridge.
Thank you for your suggestions and if I manage to stop the interferance, I will post my results.
Laurie.