Inverter or NOT ?

[BaskettoBase]

We have a 1000W inverter 2 plug and everything works fine on it with the 110 amp/hr leisure battery. We have just bought a 800W car vacuum hoover to make life easier, however when we connect the hoover to the inverter, the inverter trips out after a few seconds, resets itself and tries to power the hoover again to no avail.

Has anyone got any idea where I am going wrong?

 

[Damian]

Have you checked the battery voltage?

The inverter will trip out when the voltage drops to a pre determined level as set by the inverter to save the battery from over discharging.

 

[BaskettoBase]

Hi Damian,

Just charged battery on way home for 400 miles from Cornwall,checked voltage and reads 13.12v.

Connected battery to inverter,and plugged hoover in and the inverter trips out again.

If it helps, on the inverter it reads.....Sky-Tronic DC to AC Soft start power inverter. 12vdc to 230vac. 1000W continuous Power .Reverse polarity protection....

The wife thinks that having 2 x three pin outlet sockets that it could only be 500w per socket......????

 

[alaintaylor]

Hi

Your inverter is fine and will provide the same power to all unused sockets. I presume you are only using one appliance at a time, i.e. the vacuum cleaner? Any more and you will of course reach max power capacity. The likely problem is that the vacuum motor draws much more power when starting up - a power surge - and very common to many appliances, especially motorised appliances and microwaves. Nothing you can do about that I'm afraid and getting a higher power inverter may well be pushing the limits of the battery.

Alan

 

[rob_jax]

Hi,

Your reading of 13.12 volts means that the battery is still "adjusting" itself after being charged - it should settle down to a no-load value of between 12.6 and 12.9 volts depending on the type of battery.

But it does indeed sound as if the battery is fully charged - but what that means in terms of current capacity isn't easy to determine.

1000 watts means a current draw from the 12 volt battery of at least 85 amps - and that assuming the inverter is 100% efficient - and they're not.

So if I include a typical estimate for inverter efficiency, that means your 800 watt Hoover is going to draw a continuous 75 Amps from the battery.

And a few things pop-up from this:

1. The wiring from the battery to the inverter would need to be seriously heavy duty - otherwise voltage drop is going to be a problem - and the inverter will see this as a low voltage and cut out

2. The battery might not be able to delivery a continuous current of 75+ Amps

3. As a comparison, 75+ Amps is two or three times the normal current that a motor-mover should draw...

Suggestion: A dust pan and brush might be easier...

Robert

 

[WoodlandsCamper]

The 800W you mention is the 'output' power. Any electrical device is less than 100% efficient, therefore the 'input' power will be significantly more, probably over 1000W and your inverter will trip.

Regards

 

[BaskettoBase]

Cheers Alan.....returned to work tonight and the census off the production electricians suggest that you are the closest to the problem I have......Thanks.

 

[BaskettoBase]

Hi Rob_jax ...already bought the significent half a gleaming new Dust pan & brush......but she tells me its my job as she is on holiday !

 

[BaskettoBase]

The 800W you mention is the 'output' power. Any electrical device is less than 100% efficient, therefore the 'input' power will be significantly more, probably over 1000W and your inverter will trip.

Regards

Thanks Woodland Camper ..........think i will stick to putting paper around biscuits !