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Need help from some of you 'leccy techies' out there, please.

I have a small inverter - "AC Anywhere 140W"

I was hoping to use it this weekend to run the mains built-in pump for our large airbed. The pump is rated at 110W so I was hoping that would be OK.

However I have hit a problem even before plugging in the pump. On plugging the inverter into our 12 V power pack, the led indicator is shining red, rather than the more re-assuring green glow. Wondering whether our power pack was lacking the necessary 'oomphh' I took the inverter and plugged it into the car cig lighter. Still the same, even with the engine running.

When all else failed, I found the instructions and have read that the red light will come on if the incoming voltage falls outside the range of 10.4V - 15V (checked supply on power pack (13V), and assumed car battery to be OK, so this is unlikely),

or,

"the continuous draw on the device exceeds the design parameters of the Inverter."

Problem is, I don't have anything plugged into it yet, so I don't see how it can "exceed the design parameters"!!

Only glimmer of hope is that fleetingly when I connect the inverter to the 12V power pack, I do notice a split second of green glow, before it is overpowered by a stubborn red light!!

Do I have a dead inverter? Or is there hope? Any suggestions gratefully received.

( It is a king-size double height beastie of an air-bed, so you will understand my lack of enthusiasm as the thought of pumping it up by hand!)

It doesnt sound good for the invertor.

With the pump you will probably not be able to run it for 3 mains reasons Power factor, not an easy one to explain but basically a motor may be rated at say 110w but may require 140w to be available (it will only use 110 w, but will refuse to run if 140w is not there, please dont ask for full explaination otherwise I could be accused of being patronising)

The other reason is start up current this can often be way over double the normal running current, some cheaper invertors cannot cope.

The next reason is that most invertors are poorly rated ir it may be 140 w but for 5 min max at say 10 degree's max, Sterling invertors are rated exactly as they say ie a 150w invertor will give 150W 24/7 up to 40Degree's

BTW I would try it with the load on (ie plug the pump in) saw another cheap make before that always said battery low, but everything worked ok under load.

These power packs are ok for what they were designed for emergency starting, for anything else a bit naff, the tiny battery inside is rated at say 17ah.

For those that already know all this, I am extremely sorry for wasting your time, apologies also for the accuracy of this post.

It contains no hidden meanings, subtext and contains no nut products

George,

Thanks so much for taking the trouble and time to respond -  I suspected it was something 'terminal'!

Just tried to connect with the 'load' already plugged in, but it just squeaked a bit and died.

Just off now to stock up on Mars Bars to bribe the kids to do the pumping!

Thanks again!

Bev