# 3 phase generator



## Mattm (Jun 2, 2020)

Morning everyone I have a 3 phase generator rated at 6.5kva that I need to power a machine rated at 4kw the only problem is the machine is only single phase what's the best way to get it to run on the generator? The machine is currently wired to a 5 pin 16 amp plug wired to earth neutral and L1 on the 5 pin plug but this seems to be overloading the generator. What's the best way to get this to work? Any advice is greatly appreciated.


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## Melson (Dec 8, 2019)

This question is a good one for @KRE. 
But, I'll take a stab: My guess is you're running right the edge of the generator's capability.

The difference between kw and kva is pf. Still, even if we assume a .92 pf ... _theoretically_ ... the generator would pull that load, but it is now fully and completely maxed out with nothing left; once the frequency and/or voltage begins to droop it can't recover. 

There is another factor that relates to the output and that is the design of the regulation. The issue of severe unbalanced loading of the windings - never a good thing even with large commercial generators that usually have a robust reserve in mechanical and electrical capabilities- may interfere with the generator's AVR, depending upon its design.

Unless the generator is capable of reconfiguring, then you might be looking at either a 3 ph -to- single ph transformer, or, a properly wired & spec'd generator for 120/240 output.


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## Mattm (Jun 2, 2020)

Could the heat have anything to do with it it was sat in direct sunlight about 26 degrees centigrade


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## Melson (Dec 8, 2019)

Doubtful


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## Mattm (Jun 2, 2020)

Fair enough might be best to look into a transformer


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## iowagold (Jan 22, 2020)

or change the motor to 3 ph.


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## KRE (Nov 29, 2011)

Mattm said:


> Morning everyone I have a 3 phase generator rated at 6.5kva that I need to power a machine rated at 4kw the only problem is the machine is only single phase what's the best way to get it to run on the generator? The machine is currently wired to a 5 pin 16 amp plug wired to earth neutral and L1 on the 5 pin plug but this seems to be overloading the generator. What's the best way to get this to work? Any advice is greatly appreciated.


What is the load your trying to power? Is it a reactive or resistive load? Normally when using a genset that is rated for 3 phase, but powering a single phase load you have to reduce the KVA rating by 33.33% as you are not loading all of the stator coils, evenly. The KW rating remains the same as that rating is at the flywheel an does not change. If you trying to power a reactive load, remember as voltage goes down, amperage goes up. In a resistive load as voltage goes down so does amperage, but also in a resistive load as voltage goes up, amperage does as well. To help you further I need to know what the load is.

Contrary to whats been side above depending on load you can use two (2) single phase transformers hooked to a gen set wired for 3 phase an pull single phase off it. Now that said, as long as you do not exceed the amperage rating of the stator windings on any leg you can just pull from any two (2) legs an not hurt the stator.


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## iowagold (Jan 22, 2020)

I guess we need to ask, " hey matt what make and model is the generator?"
then we can look up specs and wiring on the generator.


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## Mattm (Jun 2, 2020)

Thank you for the replies this is the generator


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## iowagold (Jan 22, 2020)

ok may be this one?
MIL SILENT GERMANY GENERATOR ML8500W NEW MODEL 2020 PETROL AIR COOLED | in East End, Glasgow | Gumtree
and what is the tag on the equipment you wish to run?


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## Mattm (Jun 2, 2020)

That's the one and its 4kw 220-250v 16amp


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## Mattm (Jun 2, 2020)

Its 16 amp 230v, 4kw


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## Mattm (Jun 2, 2020)

Would this work?









Power Splitter, 16 AMP 400V to 3x 16 AMP 240V | eBay


Find great deals for Power Splitter, 16 AMP 400V to 3x 16 AMP 240V . Shop with confidence on eBay!



www.ebay.co.uk


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## KRE (Nov 29, 2011)

Mattm said:


> Its 16 amp 230v, 4kw


Again is this a reactive (motor or transformer) load, or is this a resistive (heating) load. Or are you trying to power a device that charges a battery bank, that is full of SCR's, ect? Or a combo of all the above???


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## Mattm (Jun 2, 2020)

KRE said:


> Again is this a reactive (motor or transformer) load, or is this a resistive (heating) load. Or are you trying to power a device that charges a battery bank, that is full of SCR's, ect? Or a combo of all the above???


Ill not sure it's a carbon cleaning machine that splits water into hydrogen and oxygen


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## iowagold (Jan 22, 2020)

Mattm said:


> Ill not sure it's a carbon cleaning machine that splits water into hydrogen and oxygen


send a link for the machine please.


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## Mattm (Jun 2, 2020)

iowagold said:


> send a link for the machine please.











HHO Carbon Clean Machines | Finance Available | Call 0203 507 0175


View our range of HHO Carbon Clean machines for all types and sizes of workshops. Competitive pricing and finance options, plus industry leading.




www.carbon-clean.co.uk


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## Mattm (Jun 2, 2020)

It's the second one down the CC-16


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## KRE (Nov 29, 2011)

Mattm said:


> It's the second one down the CC-16


Based upon the spec's of the machine and your generator, my advice is to buy a larger single phase gen set.


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## Mattm (Jun 2, 2020)

KRE said:


> Based upon the spec's of the machine and your generator, my advice is to buy a larger single phase gen set.


No worries cheers for the help


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## iowagold (Jan 22, 2020)

I did not see the specs at least what i was looking for..
does the unit have a tag on the rear that shows the voltage and power?


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## iowagold (Jan 22, 2020)

we need the power factor and the real current spec on the hho generator unit.

a couple of numbers i came up with was 18 amps and 21 amps... as the real power consumed..
so I would look for a generator that will do 30 amps rms or a bit more at the 230 volts.
or call the mfg and ask for a recommended generator for your use..


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## ToolLover (Jan 13, 2020)

With much discussion about this post, I want to touch on power factor (PF).
I worked in a 25 acre plant that had a terrible PF. The problem was starting so many manufacturing machines.
Our power factor was solved by installing a high horsepower three phase motor and letting it run without load.
This may have no bearing on the posted problem, buy it sure can improve power factors for starting unbalanced loads.


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## iowagold (Jan 22, 2020)

yup TL
the inverter drives help but are not a cure..
back in 1999 we dealt with a wet milling plant that had the same issue...
BIG motors!! 2000 hp electric on 880vac multi phase.
I think it was 12 phase. if my memory is good today.
they made their own power on site, steam turbine fired by coal.
they used it on an ALLIS-CHALMERS brand mr compressor.
super large 8 foot disc what looked like a snail or compressor part of a turbo.
BIG 2 speed gear box with an 8" shaft!!
real world running speed of a bit over 30k rpm.

they had 2 of those monsters!!
they did a bump role to start it...
the whole plant dimmed when they did the power bump.
you could see the 80kv high voltage over head power lines in the sub station feed jump!!
that was something to see!!

they went for a start on the second unit as a hurry job and blew the doors off the BIG fuse cabinet!!
lol
I was hiding behind the concrete wall!!
I had ear plugs in and it still sounded like a full stick of TNT!!
one of the young guys was leaning up against that door till I pulled him to cover just in time..
yea he would to have been burger for sure!!

power factor is a big thing..
all that fancy math and high tech equipment or old school low tech for the correction.


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## Melson (Dec 8, 2019)

Hey ToolLover, this is the kind of stuff that would get me excited, IF I was an engineer. Which I am most definitely not. 
I can state that the telecom industry I worked in definitely had pf issues, but nothing like you're talking about. My career included the gamut from small to large facilities, and the power factor rarely dropped below .89. That's even for facilities with several floors of 400, 800 and 1600 amp rectifiers, fluorescent lighting, and etc. 
I realize that large industrial complexes can have seriously poor power factors and I'd love to know about this. I'll bet they're loath to pay for the apparent electrical demands. OTOH, the only concession that AT&T and Verizon made to this issue, that I know of anyway, was to specify a .85 pf generator rating, from 4 MW turbine and diesel sets, all the way down to the lowly 28kw VertiPacs. Meaning that the manufacturer would guarantee the prime mover had the HP to push full rated load into a .85 pf.
Interesting stuff you ask! Wish I knew more.


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## KRE (Nov 29, 2011)

All Prime movers are rated in KW or KWe (true power). All 3 phase A/C alternators are rated in KVA only. Most Power company (utility's) only charge a PF (power Factor) correction fee if the PF is lower than 0.8 lagging. Most large consumers will install a cap bank instead of paying the PF charge.


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