inverters

Submitted: Monday, Jun 25, 2012 at 13:58
ThreadID: 96482 Views:2060 Replies:8 FollowUps:9
This Thread has been Archived

Related Pages

Hi all.
I am considering installing a 12volt inverter to my van so that I can run my small absorbsion fridge and waico fridge on 240volt whilst travelling. The van is quite old and not fitted with a 12volt battery so the feed would have to come direct from the vehicle start battery. Can it be done safely this way and what are the good brand names to look for. I have heard of people being zapped and worse sosafety is paramount to me.

Thanks Jim
Back Expand Un-Read 0 Moderator

Reply By: Member - John and Val - Monday, Jun 25, 2012 at 14:12

Monday, Jun 25, 2012 at 14:12
Jim,

Forget running an absorption fridge from your vehicle electrics, with or without the inverter. These fridges use far too much power for running from a vehicle battery. They are ok while the engine is running and providing the power, but too demanding once the engine has stopped.

Cheers

John

J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein

Lifetime Member
My Profile  My Blog  Send Message

AnswerID: 489379

Reply By: Member - Brian S10 - Monday, Jun 25, 2012 at 14:16

Monday, Jun 25, 2012 at 14:16
forget it.
AnswerID: 489380

Reply By: Member - Fred B (NT) - Monday, Jun 25, 2012 at 14:18

Monday, Jun 25, 2012 at 14:18
Hi,
I would recommend that you put in a 2nd battery with a DC to DC charger between your start battery and the 2nd battery (with isolator) so you do not flatten your start battery.

You will use extra power by going from 12V to 240V and using an inverter. Good chance you will flatten your start battery. A good fully charged aux battery will run your fridge for several days under normal conditions.

However, inverers can be installed safely if done correctly. Good inverters can be bought for a reasonable price from Jaycar. But you will need to know what your load is you can buy the correct one. Again... I suggest you stick with DC to DC.
regards
Fred
Fred B
VKS 737: Mobile/Selcall 1334

Lifetime Member
My Profile  My Blog  My Position  Send Message

AnswerID: 489382

Follow Up By: Member - Fred B (NT) - Monday, Jun 25, 2012 at 14:21

Monday, Jun 25, 2012 at 14:21
Sorry, forgot to mention as others have done.... I wouldn't attempt to run an absorption fridge from your vehicle.
regards
Fred B
VKS 737: Mobile/Selcall 1334

Lifetime Member
My Profile  My Blog  My Position  Send Message

0
FollowupID: 764524

Reply By: skeety46 - Monday, Jun 25, 2012 at 15:06

Monday, Jun 25, 2012 at 15:06
sorry guys I should have made it clear the fridges would only be running with
the vehicle engine running while on the road. Would then switch caravan site
power 240 cheers
AnswerID: 489384

Follow Up By: Member - John and Val - Monday, Jun 25, 2012 at 17:01

Monday, Jun 25, 2012 at 17:01
OK Jim!!! That's different!!!

I'd run the compressor fridge on 12V rather than from the inverter. Does the absorption one not have a 12V option? If it does, I'd again go with 12V. If not then an inverter should work ok, if inefficiently. Suggest if you must go to an inverter, check the rating plate on the fridge to determine it's power requirements, than allow at least 25% margin to decide on how big the inverter needs to be. As the inverter will only be used to run a heating element in the absorption fridge, you'll get away with a cheap and nasty one (provided it doesn't have to run the compressor fridge too) - no need for an expensive sine wave type. My guess is that you'll need a 300 watt one. The 12V wiring to the inverter will need to be heavy gauge, at least 8 B&S, (smaller B&S numbers relate to bigger wire) and should be fused close to the battery

Safety - A metal vehicle is an inherently dangerous place to have high voltage, so I'd minimise 240V wiring (maybe mount the inverter in the fridge itself??) and be careful that 240v wiring can't chafe on anything.

Cheers

John
J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 764536

Follow Up By: Member - Rod N (QLD) - Monday, Jun 25, 2012 at 17:17

Monday, Jun 25, 2012 at 17:17
You should have some form of automatic device to disconnect the fridges from the vehicle when the engine is not running to prevent flattening the vehicle battery.
0
FollowupID: 764538

Follow Up By: skeety46 - Tuesday, Jun 26, 2012 at 10:25

Tuesday, Jun 26, 2012 at 10:25
Thanks john for the good info I feel a lot wiser. As I said safety was my main
concern. Don't want to be running around in a 240volt live subaru A
Cheers Jim
0
FollowupID: 764613

Follow Up By: Member - John and Val - Tuesday, Jun 26, 2012 at 10:47

Tuesday, Jun 26, 2012 at 10:47
Jim,

Rod makes a good point. The cheapest way of providing automatic switching is probably to use a 30A headlight relay wired so the coil is driven by the accessory line from the ignition switch, maybe through a dash mounted switch if you'd like an easy way of manually turning it off. (Eg while starting.). The back of the cigarette lighter socket is usually a good spot to pick up the accessory voltage. The power for the fridge/inverter should be sourced directly from the battery via a 30A fuse then switched by this relay (ie don't try to pull high current from the accessory line).

Good luck with it.

Cheers

John
J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 764616

Follow Up By: oldtrack123 - Wednesday, Jun 27, 2012 at 10:26

Wednesday, Jun 27, 2012 at 10:26
Hi
Quote John "Safety - A metal vehicle is an inherently dangerous place to have high voltage, so I'd minimise 240V wiring (maybe mount the inverter in the fridge itself??) and be careful that 240v wiring can't chafe on anything. ""'

I am very pleased to see THAT point made

That is the only way I would suggest an inverter be used to power the fridge
Mount the inverter as close as possible to the fridge ,use well protected wiring from the inverter to the fridge .!!
Peter
0
FollowupID: 764695

Reply By: Nutta - Monday, Jun 25, 2012 at 20:31

Monday, Jun 25, 2012 at 20:31
The end of your first line read 'whilst travelling', shows no one read it right!
AnswerID: 489402

Follow Up By: GT Campers - Tuesday, Jun 26, 2012 at 10:02

Tuesday, Jun 26, 2012 at 10:02
while /whilst travelling, or while in transit?
0
FollowupID: 764610

Follow Up By: Member - John and Val - Tuesday, Jun 26, 2012 at 10:55

Tuesday, Jun 26, 2012 at 10:55
Aaaah the English language!!!!

True, when stationary we aren't travelling. On the other hand when on a trip we are travelling even when we are stopped!!!

Cheers

John
J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 764617

Follow Up By: Nutta - Tuesday, Jun 26, 2012 at 20:55

Tuesday, Jun 26, 2012 at 20:55
Damn public schools!! Or is that dam?
0
FollowupID: 764662

Reply By: Mad Habits - Tuesday, Jun 26, 2012 at 12:05

Tuesday, Jun 26, 2012 at 12:05
I would hate to have to rely on a 240v supply when travelling oz, constantly requiring powered sites or a geni and paying for it every day. If I were you I would just throw in the towel and buy another van full of 12v stuff, put solar on it and make sure it has a gas compatible fridge. I know that could be viewed as a bit extravagant by some - but it's only money!
Cheers! Nigel
AnswerID: 489451

Reply By: skeety46 - Tuesday, Jun 26, 2012 at 12:55

Tuesday, Jun 26, 2012 at 12:55
Thats what the missus would love mate. I won't show her your comment Ha
but thanks jim
AnswerID: 489456

Reply By: Shaun5362 - Tuesday, Jun 26, 2012 at 13:00

Tuesday, Jun 26, 2012 at 13:00
Hi Jim,
Having 240v on in a trailer whilst travelling can become dangerous to you and others in the event of an accident. Think of someone coming to the aid of passengers of a rolled car and trailer only to be zapped by 240vac. Small chance but still possible.
regards
Shaun
AnswerID: 489457

Sponsored Links

Popular Products (13)