Off Topic But someone here will know the answer

[wbleeker]

Hi Guys

We have been hit with bad weather, so bad in fact that we couldn't open our Pie Shop today! We normally only close for Christmas Day! Anyway we had no power for a fair while, we are looking for a backup generator
How do I work out what I need?
We had a scheduled outage a couple of weeks ago supposedly 8 to 4 that cost us $2700.00 so it is starting to look like a reality real soon!

Will

[Grahame Collins]

This will help you size your generator.


http://powerlite.com.au/what-size-generator-do-i-need/


You fellas are doing it tough down there.My thoughts are with you!


Grahame

[.RC.]

Single phase or three phase?

What sort of loads? Heating elements are easy to work out.... Electric motors need a lot bigger generator to get them started...

Also be aware when buying a single phase generator, often with a large modern one, they are three phase with three single phase outputs, so while the generator might be 15KVA, you cannot pull 15KVA out of a single outlet, but rather 15KVA out of the three combined... I have also read in such a situation you need to balance the load as much as possible..

[Bedford]

Be careful with generators in enclosed/confined spaces.

http://www.heraldsun.com.au/ipad/dad...-1226463394292

[wbleeker]

Definitely three phase we hired a 100 kva recently but probably a bit big
Will

[wbleeker]

Be careful with generators in enclosed/confined spaces.

http://www.heraldsun.com.au/ipad/dad...-1226463394292

Would have never put it inside have already planned an outside enclosure
Will

[Steamwhisperer]

Hi Will,
I can get my hands on a decent sized generator with a full attenuation system included.
If you like I could find out the specs for you. It was used as a backup to run a Telecom telephone exchange.

Phil

[chambezio]

Another thing I would look into is how "clean" do you need the power supply? Does the gear you have, have electronic controls? You may find a generator that can easily supply power for motors but could damage sensitive electronics.

You could send some/all excessive weather our way as we have only had about 80mm over more than a week

[wbleeker]

Hi Will,
I can get my hands on a decent sized generator with a full attenuation system included.
If you like I could find out the specs for you. It was used as a backup to run a Telecom telephone exchange.

Phil

That would be great Phil
Will

[.RC.]

Another thing I would look into is how "clean" do you need the power supply? Does the gear you have, have electronic controls? You may find a generator that can easily supply power for motors but could damage sensitive electronics.

You could send some/all excessive weather our way as we have only had about 80mm over more than a week

I had a chap tell me this recently, I have just bought a 15kva single phase dunlite generator, built in the early 1980's... He was telling me it may be no good for modern living as it would not produce a proper sine wave..

I was wondering why that would be as it cannot produce anything other then a sine wave as it is an AC alternator.. it is not one of those modern inverter generators...

[RayG]

Hi Guys

We have been hit with bad weather, so bad in fact that we couldn't open our Pie Shop today! We normally only close for Christmas Day! Anyway we had no power for a fair while, we are looking for a backup generator

Hey, wait a minute.... Robertson? Pie Shop ? I always stop there on the way to my sister's place in Gerroa... best pies in Australia.

Ray

[Stustoys]

I was wondering why that would be as it cannot produce anything other then a sine wave as it is an AC alternator..

If you didn't care about the voltage and didn't change the load that was only resistive, then I guess it would. I think the problems come about in a small system when you use the field coil to control V and just how good a job the reg and governor can do their jobs.
Its likely far more complicated than that for starters I assume different power factors would mess things up.

I didnt think switch mode power supplies cared that much about input?

Stuart

[Steamwhisperer]

That would be great Phil Will

Hi Will,
I'm too late. It's already sold.
It was a 15 KVA 3 phase powered by a 3 cylinder Lister diesel attenuated down to silent for inner residential night time running.
Sorry about that.

Phil

[cba_melbourne]

If you didn't care about the voltage and didn't change the load that was only resistive, then I guess it would. I think the problems come about in a small system when you use the field coil to control V and just how good a job the reg and governor can do their jobs.
Its likely far more complicated than that for starters I assume different power factors would mess things up.

I didnt think switch mode power supplies cared that much about input?

Stuart

The only things in my house that make trouble running from a generator (a cheap ALDI 2.2kW) are the computer UPS. They detect small variations in voltage and frequency, as they happen when for example a fridge compressor turs on, or the water pump turns on. Most UPS will react to these fluctuations by switching to battery power,, in order to protect the attached computers from spikes and brownouts. After a short while the battery is empty and the UPS turn itself and the attached computers off - despite the generator running all the time. For this reason, when starting the generator I turn off the UPS and plug the computers directly to the generator power. It seems not to harm them, I never had a problem with pc's, printers, monitors or laptops being plugged directly to the generator.

[Opelblues2]

Eaton 9355 UPS

Formerly Powerware 9355 UPS

The Eaton 9355 UPS provides premium double-conversion backup power and scalable battery runtimes for IT and electrical engineering infrastructure in corporate, healthcare, banking and industrial applications. Packing maximum battery runtime into a very small footprint, the 9355 UPS is a complete three-phase power protection solution. The 9355 can be equipped with an integrated, customizable power distribution module that includes a maintenance bypass switch.


I have one sitting in the back area at home. no good to me