16' Series 12 pin v 7 pin
- Thread starter coys 53
- Start date
it does depend on what you are supplying power to. I have the standard 3way fridge running thru a 12 pin plug and have no issues - does have heavier wire on the 5 pin side!
In my opinion, there are two causes of failures in 12-pin plugs that are used to power an absorption fridge using the large 35A rated pins.
An absorption fridge will draw from 15 to 25A when running on 12V, depending on the model of fridge and the wattage of the heating element it uses.
Firstly, the cables used need to run the fridge need to be sufficient for the task and are thus quite thick and not very flexible. This puts a lot of strain on the tiny terminals of the trailer plug which cops a far bit of movement when connecting, disconnecting, and traveling. The connector gets a little loose and at 15-25A you do not need much voltage drop to generate enough heat to melt the plug and or socket.
Secondly, the connectors rely on a split pin connector for each connection between plug and socket. With a bit of rough use, the gap closes in the pin and results in reduced connection force and consequently a poor connection, voltage drop, and again enough heat is generated to melt the plug and or socket.
I run our fridge from the 12-pin plug. But, I am aware of the problems and I check the terminals and spread the connectors regularly.
More importantly, I have a voltmeter permanently wired across the fridge terminals and mounted so we can see the voltage through the external fridge vent. Every time we start a journey, we check the lights and read that voltage. I normally have a 0.8V drop from the car battery to the fridge. If I see the same voltage then I know there is no current draw and I have usually not switched the fridge to 12V OR there is a problem like a blown 12V heating element. If the voltage difference is more than 0.8V then I know I have to check the connections on the 12 pin plug and spread the terminals. This has happened twice in three years. It is a pain but only takes 10 minutes to fix.
If I had my time over, I would have pulled the two fridge wires out of the 12-pin plug and connected the fridge to the car with Anderson plugs. These plugs are much more robust and are made to take the heavy gauge wire. The design of contacts on these plugs ensure a much better connection.
But we now have a system that requires much less effort than making the change to Anderson plugs.
cheers
Mike
An absorption fridge will draw from 15 to 25A when running on 12V, depending on the model of fridge and the wattage of the heating element it uses.
Firstly, the cables used need to run the fridge need to be sufficient for the task and are thus quite thick and not very flexible. This puts a lot of strain on the tiny terminals of the trailer plug which cops a far bit of movement when connecting, disconnecting, and traveling. The connector gets a little loose and at 15-25A you do not need much voltage drop to generate enough heat to melt the plug and or socket.
Secondly, the connectors rely on a split pin connector for each connection between plug and socket. With a bit of rough use, the gap closes in the pin and results in reduced connection force and consequently a poor connection, voltage drop, and again enough heat is generated to melt the plug and or socket.
I run our fridge from the 12-pin plug. But, I am aware of the problems and I check the terminals and spread the connectors regularly.
More importantly, I have a voltmeter permanently wired across the fridge terminals and mounted so we can see the voltage through the external fridge vent. Every time we start a journey, we check the lights and read that voltage. I normally have a 0.8V drop from the car battery to the fridge. If I see the same voltage then I know there is no current draw and I have usually not switched the fridge to 12V OR there is a problem like a blown 12V heating element. If the voltage difference is more than 0.8V then I know I have to check the connections on the 12 pin plug and spread the terminals. This has happened twice in three years. It is a pain but only takes 10 minutes to fix.
If I had my time over, I would have pulled the two fridge wires out of the 12-pin plug and connected the fridge to the car with Anderson plugs. These plugs are much more robust and are made to take the heavy gauge wire. The design of contacts on these plugs ensure a much better connection.
But we now have a system that requires much less effort than making the change to Anderson plugs.
cheers
Mike
You will find with a 12 pin only the extra 5 pins are larger, these are the ones for the higher current draw, @mikerezny has explained it all well, For many years I used a 12 pin with no dramas then a vehicle change meant the weight loading on the plug was causing resistance and it melted down, no such problems with the anderson, the 8 B&S cable fits nicely, no trimming . A melt down at Julia Creek soon convinces one of the benefits of an anderson.
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Anderson plugs are vastly superior at carrying a higher current like fridges, not to mention, you always have a firm and positive connection regardless of handling or terrain travelled. The only weak point is a poor soldered wire connection to the heavy AWG 6 or 8 wiring, which is highly unlikely if done properly. Agree with @mikerezny and @Drover in all respects.
Hi,
Or an inadequate crimp because the correct crimping tool was not used. The cheap crimping tool supplied in tool kits, or worse still, a crimp done with a pair of pliers because no crimp tool was handy may "just" work on a wire carrying little current. But it will not work when 15 - 20 A has to flow through it.
cheers
Mike