12 Volt issue

[Kappy]

I posted this together with other issues in another section, so though I would break it up.

Some time ago I acquired a 240/12 volt fridge/ freezer that works a treat on 240V and the price was good.

However on my venture North when running on 12V in the Bus it started sending out an alarms of sorts, works alright on 12V in other another vehicle source, so appears maybe voltage issue even though source on bus indicates 12 volts.

I rechecked both sources with a multimetre that revealed the alternate source was 12.58 volts and the the bus reading is 12.98 volts.

If I'm reading my meter correctly is showing that amps are 4.6

Can anyone advise if slightly higher voltage would trigger an alarm.

Bit confused why it works OK on one source and not another.

Cheers
Kappy

[Newcastle George]

Kappy,

Are you reading the voltages at the fridge or at the battery, it may be a wiring problem?

George

[Kappy]

Kappy,

Are you reading the voltages at the fridge or at the battery, it may be a wiring problem?

George

I'm reading the voltage at the plug that goes into the fridge, both sources are cigar type outlets.

Cheers
Kappy

[dapope]

Had a similar issue not so long ago. When I measured at the fridge compressor, it was very clear voltage drop was the culprit. I installed engel plug n socket. End of problem

[jon_d]

Ahh, Kappy,

Are you reading the voltage at the fridge WHEN the fridge is connected and running?

The problem is probably the wire diameter. When a heavy load is connected, the resistance of the (skinny) wire comes into play and the voltage drops.

When it's not connected, and you're just measuring the terminal voltage, the wire resistance doesn't come into play

[Kappy]

Ahh, Kappy,

Are you reading the voltage at the fridge WHEN the fridge is connected and running?

The problem is probably the wire diameter. When a heavy load is connected, the resistance of the (skinny) wire comes into play and the voltage drops.

When it's not connected, and you're just measuring the terminal voltage, the wire resistance doesn't come into play

Electricity is not my forte,

How do I measure the current when the fridge is running??? Please.

[jon_d]

Hi Kappy,

You need to measure the voltage at the fridge connector.

The red wire to the red probe on the multimeter.

The black wire to the black probe.


Measure the voltage when it's running.
And then turn the fridge off.

Measure the voltage when it's off.


The difference will "tell us" if you have a wiring problem.

[Kappy]

Thanks,

I just broke my 12 Volt plug, will need to source another.

[dapope]

I cant pull mine aprt to show you right now. Held the probes on the + and - terminals and waited for it to start. Or try to. Voltage display went to the cutoffpoint for the fridge and then the cycle started again. Powered it by another source. Fridge ran. Canged plugs and all was good
I knew the supply wiring was good. Ciggy sockets are very unreliable

[supersparky]

Thanks,

I just broke my 12 Volt plug, will need to source another.

I will bet that when you replace that plug, your problem will mysteriously disappear. Some of those cigarette lighter type connectors can be a little bit ordinary.