running fridge on 240v

[AIDY]

was chatting to someone in the marina recently, who had a device connected to his 12 volt fridge, that would detect 240volts were present and would run of the mains as opposed to the boat electrics. think it was something like a mototronic could be wrong device. anyone got one. do you reccommned it and where did you get it from.

TIA

 

[Bergman]

I've got a device that does that.

Mines called Julie

 

[AIDY]

/forums/images/graemlins/grin.gif

 

[LadyInBed]

Assuming that the fridge will run directly off of mains, a simple mains activated change over relay would do a job.
When mains in detected, relay operates opening DC path and applying mains to mains I/P.

 

[ccscott49]

Sorry, but why would you want that? Just run the fridge off 12 volts and have a good battery charger, which floats any loads, doesn't hurt the batteries. All the 240 volt switchover does, is operate a small inverter, built into the fridge.

 

[alb40]

The 240v supply on my waceo fridge does exactly this.

If the 240v supply is disconnected, it switches onto battery power.

If you have a waeco fridge, then you could use one of these

 

[ccscott49]

Is the compressor a mains one then? and does the 12 volts DC go through an inverter inside the fridge to run it? Got to be one or the other, either a 12v DC compressor, with a step down and recitfier for the 240 volts ac, or a mains compressor with an inverter.

Just attempting to clarify this point, it is important, to how the fridge is run and how this fridge could be run.

 

[KevB]

I agree - a decent battery charger will do the job and keep your batteries in good condition also.

 

[marcusgillies]

what you want is a Weaco MPS-50
go here:- http://www.waeco.co.uk/shop/details.aspx?c=&s=&i=&p=189

There a really good idea! i have fitted loads with out a single complaint!

 

[Rick]

The advantage of using 240v on the Waeco (Danfoss) is that it then runs the compressor on the 24 volt windings, and the fridge works better/faster (?).

 

[marcusgillies]

The fridge compressor is 12volts DC.
The Waeco MPS-50 unit takes both 230V AC and 12V DC and is basically a step down transformer/rectifier with a relay so that the 12V transformed power takes presidence over 12VDC battery power.
it can be fitted to any fridge not just Waeco models.

 

[Rick]

I think you'll find the compressor is actually dual 12v / 24v for the BD-35F and BD-50F - I've a vague recollection that the MPS-50 is 12 only, whereas the MPS-100 is 12 / 24 and same price (or was here in Australia). This all assumes of course that the poster has a Waeco unit, or at least a Danfoss BD-xxF compressor.

Just checked the Waeco site, and the MPS-50 is 240 volt input, 24 volt output.

 

[ccscott49]

I will ask again, what is the point if you have shorepower and a good battery charger??

 

[Ships_Cat]

I am wondering too?

When on shore power ours just runs off the charger, as does everything else. One would assume that if one has a 12/24v 'frig and shore power, one would have a charger as well.

John

 

[alb40]

No point, other than just letting the battery charger getting the batteries topped right up for long life, rather than having a load running to draw down the voltage.

I have my waeco running on the mains for that reason, as my battery charger isnt huge (11amps output)

If you have a large charger like the sterling, then you can leave it running off the charger

 

[ccscott49]

11amps is a lot of power, plenty for fridge, plus etc. I have two fridges, and a freezer running off an inverter, this is kept running all day, plus the occasional light, pump, fan etc. by 6 amp solar panels, so an 11amp charger would have little if any trouble. The fridge isnt running all the time. Rather obvious I guess, but I see no need whatsoever of these type of switching thingies, just something else to go wrong, not all fridge manufacturers seem to have them.