RM12 Relay

[Jimmy659]

Hi there,

After discovering a RM12 Relay (I believe its for the fridge) during a split charge system fit, I am unsure whether or not I need to keep it in place.

Background; I bought a 1989 2.0 Petrol T25 Autohomes Komet 2 years ago, I soon decided to upgrade the whole interior, after removing the old interior it was obvious that the wiring needed redoing. The fridge has now been removed and scrapped along with most of the old electrical equipment.
I plan on fitting a Waeco CR50/CRX50 (my new units are already cut to size), and I have a wiring diagram that shows the RM12 Relay fitted between the Fridge and the Zig CF8 PMS (I still plan on using the CF8 in my new build) with a feed off to a fuse.

My question is; do I need the RM12 Relay? I have bought a Waeco CR50 Mains adaptor which will have a 240V feed and a 12V feed from the ZIG CF8 PMS.

My electrical knowledge is quite limited so any guidance or info would be greatly appreciated.

Many Thanks

[nevill3]

The main reason you would use a relay for the 12 volt supply for a fridge is to prevent it from being run whilst the engine is not charging the batteries. Any battery used to supply a fridge would soon become depleted unless it was being recharged. The relay is used to connect the fridge to the 12volt system once the alternator is charging.

[Snowmark]

Jimmy - depends on how you want to run your fridge. I stripped out all my old system and wired a new Waeco directly to the leisure battery (via a fuse and switch). I have a split charge system (Voltage sensitive Relay) that will charge the car battery and then the leisure battery when the engine is running. Mains hookup will basically act as a battery charger for the leisure battery (only use it at home before a trip away) - not sure if your Zig Unit will act in that way but it might.
I have a solar panel to trickle charge the leisure battery when conditions are right.
The Waeco draws little power so we can happily camp without hook up for 4 days with the fridge on 24/7 - if the volt meter shows the leisure battery dropping we go for a drive.
The older 3 way fridges used a relay to allow the fridge to run when driving (no 240v, no gas) - not necessary IMO with the new 12V fridge.

Hope this makes sense.
Mark

[Jimmy659]

Thanks for the replies Nevill3 and Snowmark,

I understand the reason behind the relay being fitted, just not 100% sure whether it is really required with my set up. Snowmark I have bought a Split Charge kit but i'm having a bit of a electrical nightmare at the moment, keep finding loose and unconnected wires, driving me mad! I am considering following your set up and getting rid of the Zig unit altogether and installing a fuse board and battery charger.

I'll start a new topic about my whole electric set up.

Many Thanks