surge control

[Trivo]

i have a problem with my inverter when i put a fridge or airconditoiner etc on it it cuts out, i am aware that it is because of the compressor start cycle but the surge only lasts for half a second or less,it is enough to trip the inverter.

rated 2000w surge 4000w 240 vac, after the surge it only pulls 800w is there a circut that anyone is aware of that would give me that little bit extra maybe some caps on the output side?

Trivo

[drdongle]

There might be an adjustment in the inverter for the trip point but i can't recomend that you change it.

[ghurd]

Is it an older unit?

I don't know if it would work, but there is a thing called a "Green Plug".

I believe the company went under several years ago, because newer improved motors benefit much less.

An Editorial.   http://hem.dis.anl.gov/eehem/94/940901.html

Where to buy.   http://www.goldmine-elec-products.com/searchprods.asp

(serch GreenPlug if they don't show up) $0.99-10.25

Might be worth a try?

G-

[fishfarm]

Is it cutting out from overcurrent or undervoltage? If undervoltage, it could be too small a battery bank or the cables are too small from the battery to the inverter.

[Trivo]

it is a brand new unit.

it is over current not voltage.

i ran a 2000 w heat gun on the unit and it runs right on the limit of the amp so the inverter seems to work ok

the greenplug looks to be exactley what i need, pitty it is 110 v as i am on 240 v might get one and pull it to bits and see whats in it

trivo

[Chiron]

If you can't get higher current out of the inverter you might try lowering the surge current of the load.

If you can get to the start and run caps for the compressor you might try reducing the value of the start cap. That would lower the initial start up current on the compressor but if it's too low you could fry it.

The compressor will spin up slower but with less surge current. I'd start with a value 2/3 of what's in there now but wouldn't go less than half. Make sure the caps are non polarized and have at least the same voltage rating. If the compresor just stalls turn it off immediately! Any electric motor repair shop should have plenty of them in stock.

Another thought is to put a switch on the fan motor and let the compressor fire up first, then turn the fan on. A timed relay or current sensing switch, other possibilities depending on how your unit is wired but a simple hand operated switch will tell you if it will work.

The small AC unit I have draws about 500W (4.7A@110V according to an Amp clamp) while running but when I first turn it on it can kick the 15A breaker if there's anything else on the circuit. Old house, half the outlets in the place are on one breaker including the ceiling lights in all the rooms. Leave 2 lights on and and start the AC I got to run out to the garage in the dark to reset the breaker. Cheap rental, I'm not going to rewire it.

Both motors are trying to start up at the same time and I leave to "power saver" off so the fan runs all the time so I don't get the higher surge current.

HTH

..

[BT Humble]

Is it an old fridge?  I haven't had any problems running a small, old bar fridge from a 400W inverter, and my 2000W/4000W surge inverter copes quite comfortably with my washing machine (1200W starting up the spin cycle).

BTH

[arcandspark]

I would agree, if your refrig and AC are old, through them away and replace with new (Energy Star) applianced. At one site we did an install off grid the refrig pulled less than 15 watts. The problem was the Trace inverters need to see at less a 15 watt load before they turn on, so the refrig would not eve start the inverters. We had to install an under cabinet floresent light that used about 10 watts, so then the ten watts demand from the light on the same circuit as the refrig demand for 15 when it wanted to cycle on was enought to start the invert. I am running three of the new style window 5000 BTU AC that pull about 4.2 amps each with no problem at all. The biggest thing that can have an instant effect on energy saving are the new (Energy Star) appliances. They do save you a lot.

arcandspark