Inverters Feedback

Submitted: Wednesday, Aug 15, 2007 at 17:47

ThreadID: 48740 Views:3069 Replies:7 FollowUps:10

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Inverters

This article discusses how Inverters work and why they are so desirable to many travellers. It explains the difference between modifed sine wave inverters and pure sinewave inverters; contains a

JERRYNIC

I ONLY WANT TO RUN A FREEZER (940W) IN MY CARAVAN. CAN I RUN A CHARGE WIRE FROM MY TOW VEHICLE TO THE BATTERY IN THE VANIN TURN RUNS MY (1000W ) INVERTOR.

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Reply By: Mainey (WA) - Wednesday, Aug 15, 2007 at 18:17

Wednesday, Aug 15, 2007 at 18:17

In a one (1) word reply . . . . yes

AnswerID: 257392

Follow Up By: drivesafe - Wednesday, Aug 15, 2007 at 18:27

Wednesday, Aug 15, 2007 at 18:27

Hi Jerry, as Mainey post YES, but your inverter will have a very short life.

You would be better going up to a 1500w and then you won’t be running it flat-out.

Contrary to the continuos rating of any inverter, running them anywhere near their maximum continuos rating is a recipe for a very short life span.

If you know what you are going to need and in your case you do, always get an inverter that is going to be able to supply at least 50% more and you then won’t risk burn it out as easily.

Cheers

FollowupID: 518653

Reply By: Redeye - Wednesday, Aug 15, 2007 at 18:29

Wednesday, Aug 15, 2007 at 18:29

You will require a big alternator and some large conductors to carry the current required. My Nissan patrols alternator would have some difficulty running the 1000w invertor and any other items in the vehicle at the same time.

1000 watts is around 80 amps at the 12 volt end of things.

Redeye

AnswerID: 257395

Follow Up By: JERRYNIC - Wednesday, Aug 15, 2007 at 18:40

Wednesday, Aug 15, 2007 at 18:40

only require a charge wire to battery in van.
Do you feel that even just charging the battery the alternator is going have difficulty

FollowupID: 518654

Follow Up By: Mainey (WA) - Wednesday, Aug 15, 2007 at 19:15

Wednesday, Aug 15, 2007 at 19:15

JERRYNIC,
The very very small battery capacity is the problem !!

FollowupID: 518661

Reply By: JERRYNIC - Wednesday, Aug 15, 2007 at 18:34

Wednesday, Aug 15, 2007 at 18:34

Thanks everyone
Will go back and review my invertor
cheers

AnswerID: 257398

Follow Up By: drivesafe - Wednesday, Aug 15, 2007 at 22:27

Wednesday, Aug 15, 2007 at 22:27

Hi again Jerry, if you haven’t already bought a fridge yet and you still want a large type, go have a look in some motor homes.

They fit some pretty large fridges in them but they are 12 volt which means there is no power wasted through the inefficiencies of having to use an inverter but they are still up around the 30 amp mark.

Just a suggestion.

FollowupID: 518713

Reply By: SCUBADOO - Wednesday, Aug 15, 2007 at 18:49

Wednesday, Aug 15, 2007 at 18:49

Jerry

That must be one BIG freezer! Is the 940W perhaps the model number? -:)
I have a mains operated 70L freezer operating as a fridge in my van. When operating it draws 55W. My 500W sinewave inverter only just starts the compressor due to the initial surge current. If in fact your freezer requires 940W - doubtful - and uses a stardard mains operated compressor then there is no way your inverter would start the beast.

Nev

AnswerID: 257403

Follow Up By: Member - Alex K (NSW) - Wednesday, Aug 15, 2007 at 19:06

Wednesday, Aug 15, 2007 at 19:06

What might frighten you more... if plugged into GPO it would be costing you $800 in electricity alone.

FollowupID: 518659

Follow Up By: Member - Andrew (QLD) - Wednesday, Aug 15, 2007 at 19:27

Wednesday, Aug 15, 2007 at 19:27

how so?

Andrew

FollowupID: 518668

Follow Up By: Member - Alex K (NSW) - Thursday, Aug 16, 2007 at 10:35

Thursday, Aug 16, 2007 at 10:35

Andrew,
Should have said per year in my previous post.
Few assumptions but something along the lines of...

0.93Kw
24 hrs/day 365 days/yr
10c/kwh

0.93 * 24 * 365 *0.1 = $813/yr

If I'm wrong I'll apologise in advance.
Alex

FollowupID: 518757

Follow Up By: Member - Andrew (QLD) - Thursday, Aug 16, 2007 at 11:15

Thursday, Aug 16, 2007 at 11:15

Though allowing for a duty cycyle would reduce this figure immensely....in any case, yes, it is a noticable cost.

Andrew

FollowupID: 518761

Reply By: Derek from Affordable Batteries & Radiators - Wednesday, Aug 15, 2007 at 20:04

Wednesday, Aug 15, 2007 at 20:04

Hi Jerry

940W ?

Very large freezer. Keep in mind that you may have a 30% duty cycle.

24 hours x 930W @ 30% duty cycle is 6.7kw or 550 amps per day.

You would need to run the car for 10 hours a day at idle to keep up. You would also need a 3000W inverter to handle the start up current of the compressor.

I would be looking at other options. 12V Compressor Freezers or 3 way gas.

Note: For those of your ready to pull my figures apart..... these are wild and subject to actual figures to be supplied. IE: Battery capacity, Fridge make, insulation, ambient temperature, alternator output, contents of fridge..... can't believe I have to say that too.... It has just become difficult to answer a simple question without being harassed.

Regards

Derek.

AnswerID: 257427