Icemaker: What Size Inverter ?

[stevensuf]

I bought one of those portable ice makers , it runs 140w but obviously the compressor start surge is large, tried it on a 1000W inverter and it still wouldnt start, anyone using one on an inverter? and if so what size inverter are you using?

cheers

steven

[marshmat]

Steven,

Was the 1 kW inverter a true sine wave type? Or was it the cheaper "modified sine" (actually a stepped square wave) type?

Many induction motors don't play well with mod-sine inverters, but will run just fine on a pure sine inverter.

[stevensuf]

tried it on a 300w pure sign then a 500w pure sign and lastly a 1000w modified sign, all continuous ratings not peak. just stalls as the motor tries to power up, batteries are ok and cables very thick (6 guage)

[simonmd]

I have a reasonably large Contessa ice maker and it works fine with my inverter setup. However, its a 3000w pure sine wave unit so i dare say thats not surprising.

[David M]

It may not be a capacitor start motor. The capacitor adds more starting torque.

I think you need a 1000 watt true sine at the least. This will provide you with a little headroom for other AC loads. 1000 watts is only 8.3 amps.

You also want to make sure you have gauged your DC and AC wires adequately. Too small of wire and there will be too much of a voltage drop when there is a large surge load.

[stevensuf]

ok so it will work with a 3000w pure sign, now whats the least it will work with? thats the question. I already bought two inverters, don't want to buy another one till i know it will work on it!

[David M]

3000 watts true sine is way overkill if all you have is one 140 watt AC load.

Read my previous post.

What are your AC and DC wire gauges now? Also is your battery anything smaller than a Group 27?...probably not, just checking though.

[stevensuf]

Just looking for some real world figures! i thought the 500w pure sine would do, the usual rule of thumb is 3x normal running load to start load, the wiring is fine -6 gauge for 4 foot, batteries 440ah agm.

I doubt its power supply side to the inverter, more the inverters being unable to power the start surge of the motor!

[Cheechako]

I've used a microwave, saw, etc off a 1000 watt Freedom invertor before. Something tells me there is something else going on....

[stevensuf]

a mircowave doesnt have a large starting surge like compressor motors do.

[DotDun]

I have this ice maker rated @ 400W:

AI-210W NewAir Portable Ice Maker With Easy-to-Read LCD Display

Runs fine on a 1000W Xantrex Prosine (pure sine wave) which claims to handle 1500W surge.

FWIW - my 700W rated microwave will not run on the Prosine.

[Cheechako]

at 140w it shouldnt be more than 400 w startup or so though right? The Microwave used to dim the lights significantly when started. I think it drew 800-1000 watts according to spec.

[stevensuf]

been looking and without a run capacitor it looks more like equivalent of 800w on the start surge , now the 500w true sine is rated 1000w surge (but maybe for not long enough) the 1000w is 1500w surge which should be enough but it is not a true sine wave unit

[colemj]

Does it run on mains? Make sure nothing is wrong with the unit first.

Mark

[s/v Jedi]

Yah.. and size 6 wire does not sound very big to me... I have that for some of my 240V AC circuits... *ducks*

My 3kW inverter has dual AWG-0 so 2x red and 2x black. That is way more than 3x single AWG 6. I doubt you have enough voltage left during surges.

Also, 440Ah battery bank? Check voltage during start-up surge, it all sound a bit skinny to me.

On the other hand, what kind of compressor is in the ice maker? The small Danfoss compressors don't take that much at all....

Alternate plan: you're in Scotland, right? Fill ice trays and put on deck overnight

cheers,
Nick.