The Magnatek output will be a form of constant voltage for the battery charging and an unregulated 12V for the shore supply stuff.

Most of these were based on a constant voltage transformer feeding a rectifier for DC. Christy are the other big manufacturer.

They weren't too sophisticated compared with European stuff so may need a good check over before you use them.

Peter

Yes, that's the Power Converter/Charger as stated. That was the original fitted by Georgy Boy and many other RV manufacturers.
Apart from housing the 12v. domestic fuses and possibly a couple of mains (110v) breakers, the expensive and hidden bit is the 45 amp Converter/Charger.
This will power all and any 12 v. appliances like the inverter as well as charging the house batteries.

But this box is fed originally from the 30 or 50 amp power cord and or generator. but as the rig has been adapted for 240v use it will get it's feed from the secondary side of the transformer.
These transformers are often placed annoyingly under the bed just to keep you awake with their 'hum'. But it's possible the transformer could be in an outside locker where the new and smaller 240v power lead enters the rig.

A pic of the transformer would be helpful.
The 240v power lead could enter via a large power breaker and earth leakage trip. But depending on who and when it was converted might go straight to the primary side of the transformer.

The Generator circuit can also be several options.
Sometimes a more sophisticated installation will have auto changeover relays to enable the genny to power the secondary side of the transformer and in turn all the 110v appliances and via the trany feed the 240v plugs.

But other times the geny just has a large plug and socket arrangement in a compartment and when you need the genny to power everything the mains plug is pulled out and the genny plug plugged in.

But we don't know from this distance.

Ray.

Thats the problem Ray. The Magnatek is powered directly from the mains hookup - you can see the breaker at the top left of the photo.

I can't see a 120-240 transformer anywhere, and there is only 120v on all the plugs when the jenny is on, and not hooked up.

The 12v from this box does not appear to be charging the house batteries, a previous owner installed a separate mains charger next to them, that only works on hookup!

It all seems very strange to me - I am just trying to get a handle on what is standard on these RV's.

I am somewhat confused that there is no obvious transformer. A modest 2.5 to 3kva one would need to be about a foot square. Any smaller and one air con or microwave would just melt it.

I also installed separate 240v mains battery chargers as the inbuilt ones did tend to hum on 50 c/s. It was cheaper than a new Magnatec one. But it would only charge the house batteries and not feed any inverter directly.

I don't think there is any standard to RV conversions. Most dealer imports were done to a price. Apart from a basic transformer they just added a few 13 amp sockets. Maybe later ones have the ELCB trips.
Specialist RV service people in UK like Gold Motors, Steve of Mobile RV and a few others usually did a much better job and even auto change over relay/contactor for the genny power. Is there any indication as to who did import it?

Then there were the private individuals like me who just brought over a few for personal use. Again there was no standard and owners just did what pleased them.
I still have a selection of 240/110 transformers from 2kva. 3kva. and 5.5kva.

Ray.

Looking at your photos I would think you have the original distribution panel with mcb's and twelve volt blade fuses. And an after market 12 volt power supply. This will give you 110 to any original fixtures a/con, fridge, microwave etc which run at 110 volts 60 cycles. 12volts which normally runs the lights and the blown air heating. The UK plug sockets should only be live at 240 volts 50 cycles. The American 110 sockets if any are two pin with the blades offset. The things to be careful of is knowing who has done what to what. A yellow builders transformer will give you 110 volts but only at 50 cycles fine for heating elements or anything without a motor, but may shorten the life of say the roof air which wants 110 volts 60 cycles. This may also cause the transformer to overheat. You twelve volt power supply is designed to give you up to 25 amp but will only charge the batteries at 5 amps. If you are going to be off hook up much I would start to change some of the bulbs, if you have the lights with two bulbs they are usually 21 watt flasher bulbs so there's 4amps a light, the blown air can draw 6-8 amps per unit, the hot water if it a Bowmans gas one their not bad maybe 1/2 an amp. Fridge is normally gas off hook up or 110 volt when plugged in some have 12 volt for when driving but not very efficient.