View Full Version : Mobile Air Conditioning power from 2000w Inverter.

05-11-2012, 11:59 AM
Hiya Guys,
I have recently installed a 2000w modified sine wave Inverter in my van to operate my Air Conditioning tools (Sick of running out cable power)! I have the usual, vacumm pump, recovery unit etc.

The thing is...everything works fine apart from the recovery unit! On start up it fails to initiate to fire up and run, just a kind of slow clicking motor sound.
I have read up on some articles on the net without any success. I`m guessing due to the recovery unit being motor, pump operated it is sapping too much battery from the installed 110ah battery source that runs from the van battery in turn to the inverter by means of switched relay.

I have read that tools of this nature require a pure sine wave inverter but do not understand how it does in fact operate the rest of the tools including the vacumm pump.
The recovery unit operates at 480watts max output drawing 4.2 amps so I would think that the set up I currently have would be more than sufficient to operate correctly.
The inverter does for a short time supply 4000watts peak for a couple of seconds.

I have looked at calculations on line and the inverter once again does indeed appear to be capable of operating units of this nature taking into account the output of the inverter.
It is the pure sine wave thingy that is putting me at a bit of a loss.

It would be good if anyone with onboard power could direct me in making attempts to resolve this fustrating issue!

All the best!

05-11-2012, 09:12 PM
Isn't there two types of inverter, i think whichever one can run flourescent tubes will power motors without a problem, i know there is a huge difference in price here between the two.


05-11-2012, 09:29 PM
you got it ,take it to a good autoelectricion i think your inverter is not powerful enough,sometimes the rating on the inverter can be misleading the torque of the motor is high.

05-11-2012, 11:25 PM
2 types of inverters. modified square and pure sine wave. The modified square wave is the cheapest but also the nastiest. your 2kw inverter is not powerful enough. Pulling 167 amps isn't going to do any favours to your small battery either.

06-11-2012, 01:56 AM
Mike is right. Get a pure sinewave inverter, such as an "Outback" and get a deep discharge battery as well. You don't want a "depth of discharge" greater than 20% if the battery is to last long at all.

06-11-2012, 04:52 AM
Your 110 AH battery has a CCA rating. (Cold Cranking Amps) Unless you had your vehicle running to support the battery, i can't see how you could sustain 480 watts at 240 volts which is 2 amps. (40 amps + losses from the battery)
Pure sine wave inverters deliver the same QUALITY power as your utility provider. 240 volts at 50 cycles/second. Inverters here are 230 volt, 50 cycles/sec.
Modified Square delivers a very basic 215 to 230 volt supply. No sensitive equipment should ever be exposed to this rough source of power.
Another option is to purchase a pure sine wave petrol generator. There are many brands out there but i only trust the "EU-20-I" Ran up 6000 hours on one and currently at 2300 hours on another.