andersen plug circiut breaker

Bukhouse · Veteran Member

andersen plug circiut breaker

iana · Guru

As I understand it, the fuses and circuit breakers are there to protect the wiring, not the appliance.

Warren-Pat_01 · Guru

Hi Bukhouse,
I would do a gestimate on what the load in the van will be, add 5A & fit a breaker to suit. An absorption 3-way fridge draws around a constant 17A. You will find a 25-30A cct breaker reasonably easy to purchase. If you have one of these, fit a Fridge Switch on the van to isolate the fridge from the car's battery when you are stationary.

A DC fridge will draw considerably less current (5-10A) & it cycles on/off.

Be wary - there are two types of breakers available. Self (auto) or manual (done by you) resetting. Both have pros & cons but I saw camper trailer that was almost destroyed by fire at Mt Isa a few years ago. The self resetting breaker kept doing that - resulting in $8,000 damage to the batteries & "flash" power board!

Bukhouse · Veteran Member

Hi iana and Warren-Pat,

Thanks for the reply's

Yes I think I will go with the 30amp manual reset

PeterInSa · Guru

I installed similar one of these see below, not necessarily from this supplier but around the same price.

Anderson plug at the rear with thick cable can run my 12v air compressor at 45Amps with the engine/alternator running.

www.ebay.com.au/itm/12V-24V-Car-Auto-Boat-Audio-Fuse-Holder-50Amp-Manual-Reset-Circuit-Breaker/152820212414

Peter

oldtrack123 · Guru

iana wrote:
As I understand it, the fuses and circuit breakers are there to protect the wiring, not the appliance.

Correct smile

oldtrack123 · Guru

Bukhouse wrote:
Hi All,
I'm running 6 B&S twin core cable from auxiliary battery in tug to 50 amp Andersen plug on rear off tug to run fridge in van
I'm wanting to fit circuit breaker near tug auxiliary battery

question is do I fit 50amp breaker or 30amp breaker ??
advice welcome

Are you only going to run the 3way fridge from that line or will you also be charging van battery?

If both ,as I suspect , you need to take the batteries charge current into account

Size could even be up to 50/60A . Remember it's prime purpose is protection of the cable . [shorts causing overheating & fire

Don't forget you also need to fit protection as close as possible to the current source [alternator]

JBDUBBO · Veteran Member

Plus a 20 amp fuse just before fridge.

PeterD · Guru

There is absolutely no point in putting a fuse in line just before the fridge. The fridge does not feed power to the supply cable so a fuse is not needed. If you put one in it is just another potential fault to show its ugly head. If a dead short occurs in the fridge then the fuses at the power sources will save the day.

oldtrack123 · Guru

Following from Pd 's post
Perhaps it is time to explain further on when,why & where fuses should be placed
[1]Fuses primary purpose is usually to protect the cable from overheating due to excess current
[a]To do this it needs to be fitted as close as possible to the power source
It must not have a current rating higher than the cables it is protecting ,but it can be lower, in fact should be lower, if the cable is large purely for voltage drop reasons[
[c] if is the situation ,the fuse size should be based on the maximum connected load current be that a single devise or multiple devices.
[d] If branch cables are run from the large cable,[teed off]The fuse rating should be no higher than the current rating of the smallest cable or the cables should be individually fused ,with a fuse no bigger than than that cables current rating, & near as possible to the take off point
[e] Fuses are not ideal for overload protection of equipment [thermal overloads or better, temperature sensors, should be censidered]
[f] fuses are available in many different types for different purposes.
Such as:
[g] fast blow which ,as the name implies ,are designed for quick operation & are for situations where the rate of current rise could be quite fast.
[h] slow blow ,can take excess current for a short period without blowing ,used when short term surge currents can occur such as motor start up
[h] small cartridge fuse are also available in numerous types even in 12V .
fast blow glass
slow blow glass
12v wedge fuses are not available in the same range. of duties
[j] 240 v have a much larger range from standard to high rupturing capacity[HRC] but not something that should be of interest to this forum

-- Edited by oldtrack123 on Thursday 21st of February 2019 07:45:07 PM

JBDUBBO · Veteran Member

In my working life as an electrical contractor I was involved in wiring Pivot irrigators sometime up to 500 meters from the supply. So we could use 2ooamp cables to supply 2o amp motors.

Guess what size circuit breakers we used??

Use the same theory for wiring 3 way fridges.