Pure sine wave inverters

Submitted: Thursday, Apr 23, 2009 at 22:07

ThreadID: 68150 Views:3173 Replies:8 FollowUps:1

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Inverters

This article discusses how Inverters work and why they are so desirable to many travellers. It explains the difference between modifed sine wave inverters and pure sinewave inverters; contains a

Serendipity of Mandurah (WA)

I just bought a 300w nominal 600w peak pure sine wave inverter for $130 new on eBay. I was hoping this is what I needed for powering my cordless makita tools. The charger is rated at 240w so I am thinking even with a bit of a surge it should handle it. Maybe I just don't get this electrical stuff. I know my mate recons that all electrical stuff runs on the blue smoke and when you lose the blue smoke nothing works again.

Anyway when I received this inverter I plugged in my makita charger only to have it overload in 30sec and go to the red light with a buzzer. Tried over and over to the same effect. Tried a 130w fan no worries. Tried a 65w laptop charger no worries.

My question is why should my makita charger which is rated less than the inverter trip it out. Should say this was connected to a fully charged good condition deep cycle battery with the very short supplied cable. I tried other batteries and other cables, even directly to the cruiser battery with the car running.

David

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Reply By: Ianw - Thursday, Apr 23, 2009 at 22:25

Thursday, Apr 23, 2009 at 22:25

The key might be the $130, not the 300w
Ian

AnswerID: 361169

Reply By: Member - Paul W- Esq (VIC) - Thursday, Apr 23, 2009 at 22:34

Thursday, Apr 23, 2009 at 22:34

maybe the "pure" is not so pure. i have one also but my hitachi battery drill charger will not work on it but the panasonic charger will?? go figure.

AnswerID: 361173

Reply By: ABR - SIDEWINDER - Thursday, Apr 23, 2009 at 22:37

Thursday, Apr 23, 2009 at 22:37

Hi David

The 240W would be the running current of the Makita charger which is close to the max of your inverter. The start up current of the charger could be 350W to 400W and the peak of the inverter for $130 would only be 0.5 to 1.0 seconds ?, which may not be long enough for the charger to stabilize. - Check the specs and let us know.

Also the supplied cable may be too thin. 600W would require 100A cable to ensure no voltage drop over 1 or 2m. So the cable should be 8 B&S (Slightly thinner than a pencil).

Regards

Derek from ABR

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AnswerID: 361174

Follow Up By: Serendipity of Mandurah (WA) - Friday, Apr 24, 2009 at 08:34

Friday, Apr 24, 2009 at 08:34

Thanks Derek

The actual unit cost $80 with $50 for transit so I took a risk in buying cheap. I think you are right in that the peak of the inverter is not long enough. At that price the instructions don't cover much. If my needs get more serious I might have to dig deeper in my pockets.

David

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FollowupID: 628925

Reply By: time waster - Friday, Apr 24, 2009 at 07:11

Friday, Apr 24, 2009 at 07:11

I had the same issue with an inverter overloading and as Derek said it was when plugged in the cigarette fitting but not when connected straight to battery, the cigarette wiring was too thin and did not carry enough current.

AnswerID: 361197

Reply By: Maîneÿ . . .- Friday, Apr 24, 2009 at 07:49

Friday, Apr 24, 2009 at 07:49

David, "powering your *CORDLESS* Makita tools" should be easy @ 300 watt (nominal peak 600 Watt) inverter.

I've run my 240v, 13mm impact drill from my 300W inverter, even with it's stated input power of 550 Watt.
Image Could Not Be FoundMainey . . .

AnswerID: 361205

Reply By: Member - Mike DID - Friday, Apr 24, 2009 at 07:52

Friday, Apr 24, 2009 at 07:52

Try it with the engine running - the voltage will be slightly higher meaning the Inverter will draw slightly less current.

Connect a double adapter to the Inverter output and connect a 50 watt lamp to one outlet - then plug in the charger - then unplug the lamp.

When supplying 240watts the Inverter will be drawing 24 amps - your battery and wiring may be causing excessive voltage drop at the inverter.

Buy a $20 Multimeter and measure the voltage AT THE INVERTER under load.
.

AnswerID: 361206

Reply By: Serendipity of Mandurah (WA) - Friday, Apr 24, 2009 at 08:46

Friday, Apr 24, 2009 at 08:46

Thanks for the replies.

I think the only problem really is the price a paid for a sine wave inverter. Oh well - it still works. Gearing up for some good times when camping can get expensive.

David

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AnswerID: 361215

Reply By: RV Powerstream P/L - Friday, Apr 24, 2009 at 20:02

Friday, Apr 24, 2009 at 20:02

Ir your Inverter is light then it is a high frequency Inverter and as such the surge factor is miniscule and once you exceed the continuous duty they are not worth a spit.
If you want surge capacity you need a low frequency unit which is heavy.
Ian

AnswerID: 361347