Fridges and power drain

[sprocker]

The fridges (Large one in galley, small one in cockpit) on our Sessa can be turned on whether we are connected to shore power or not.

Obviously if we are not connected to shore power the fridges will put drain on the batteries.

However, if we are connected to shore power does the fridge power usually come via the batteries, or direct from the mains (i.e. Are they likely to be auto switching). I guess what I am trying to learn is do I need to have the battery charger on whenever I have the fridges on.

 

[longjohnsilver]

The fridges (Large one in galley, small one in cockpit) on our Sessa can be turned on whether we are connected to shore power or not.

Obviously if we are not connected to shore power the fridges will put drain on the batteries.

However, if we are connected to shore power does the fridge power usually come via the batteries, or direct from the mains (i.e. Are they likely to be auto switching). I guess what I am trying to learn is do I need to have the battery charger on whenever I have the fridges on.

Almost certainly they will switch directly to 240v when on shore power.

 

[sprocker]

Thankyou for your reply LJS, that is what I was hoping for.

 

[vas]

Almost certainly they will switch directly to 240v when on shore power.

LJS,

why?
unless the fridge has two power inputs 12/24 and 220, it wont.
A fairly recent waeco I have is 12/24 only
an old frigoboat (or something like that) that came with MiToS has an expensive external box that does the 220 24 switching.

I think the best for OP is to check current draw on 12/24V system with fridge running and turn on and off the bat.charger to see if there's a difference in Amps on the batteries load.

cheers

V.

 

[AllanG]

My Waeco fridge is connected to a Waeco CoolPower MPS35 mains rectifier, which automatically switches from battery to mains operation, when connected to shore power.

So, I would suggest checking if your fridge is connected to such a rectifier.

 

[dpb]

I've had 1 boat with dual voltage fridge that switch automatically with priority to 240v, 1 with 12v only and one of the former where the 240 side didn't worked so operated like the latter. So you need to check.
If he mains panel has a fridge circuit breaker that would be a clue.
Otherwise connect the mains power and switch the batteries off and see if the fridge still works.

 

[Freeloader]

I think you will find that they are 12v only, so you will need to keep the battery charger on to (effectively) run on shore power. It's a good suggestion by DPB to switch the batteries off and see if they still run on shore power but I think you will find that, on the Sessa, the fridges will just cut out as soon as the battery is disconnected.

As an aside, is there any point in switching the battery charger off anyway?

 

[vas]

As an aside, is there any point in switching the battery charger off anyway?

yep, if you're not so sure they are good enough to work 24/7, and most of the older ones aren't...

cheers

V.

 

[sprocker]

Thankyou for all your replies gents, after giving this some thought I am fairly certain that the switch for the fridge is on the 12/24v side of the main panel.

I'll try and get a tester on it at the weekend just to make sure.

 

[Portofino]

Both mine are also auto switch from 24 V to any 220v --shore or Geny .
I know that because one had a prob ,it would not auto its self to 220 v ,so as it loaded the domestic bats more if the V dropped to below a certain level - to protect the batts from a deep discharge ,the Fridge turn off by it self .Most annoying in the Med in August on a visiting bouy or berth with zilch or intermittent shore power , especially as it was the cockpit drinks chiller -- warm rose and beer :disgust:That outing

Electrician fitted a new one ,most proper boat and I suppose motor home fridges should auto switch --worth checking out that tiny detail if you ever need to buy another .