Thread: limited power

15A 240v is ~3.6Kw
So 7Kw should handle most things a standard power point would.
Should start ?? most 15A start motors (2Hp)

Thanks David,I'll go check a few catalogues and see what's available.

I'm definitely looking for more information on the types of bandsaws available in Australia, so rather than reinvent the wheel,you might like to visit the subforum ;Boatbuilding/repairs, thread;bandsaws. Hope you can help if it's not too much trouble.Cheers

Originally Posted by DavidG

15A 240v is ~3.6Kw
So 7Kw should handle most things a standard power point would.
Should start ?? most 15A start motors (2Hp)

Doesn't always work like that - a 3HP motor rating needs a few tenths of a second at 2 or even 3 times its 3HP running current to start. Breakers are designed to cope with that but basic inverter type systems can struggle to maintain both current and potential.

Depending on how efficient the motor is, a 3HP TS will draw up to 45A when starting, use about 5A free running, 7A under light cutting 10 heavy cutting and above 12A or so it will start to slow down. I have gotten my TS to draw 17A (or x 240 v /750) = 5.5 HP!

Most decent inverters have a surge rating of double their run rating.

Given he has a 7kw run rating inverter that gives a surge rating of 14kw.
Max surge current of 58A.

That should be enough to start all 2hp and most 3hp motors

ps My bandsaw has a 2hp motor and a start current of 11.5A

An opportunity for a keen electrical engineer or experimenter to invent a device that charges the capacitors first just before it switches the power to the motor so the caps arn't empty at the start. Should be doable but nobody seems to have run with it ?

Originally Posted by tytower

An opportunity for a keen electrical engineer or experimenter to invent a device that charges the capacitors first just before it switches the power to the motor so the caps arn't empty at the start. Should be doable but nobody seems to have run with it ?

But, but, but It is the charge/discharge of the capacitors that give the phase shift required to run the motor.............