3 phase or single phase

[singingfraggle]

Hello all I have been asked to supply power and cableing for an out side event total loading will be 41kva no three phase required .but my question is as I have never really needed a large genny am I better off using a single or three phase genny thanks for any advice given paul

 

[Sparks1962]

Hello all I have been asked to supply power and cableing for an out side event total loading will be 41kva no three phase required .but my question is as I have never really needed a large genny am I better off using a single or three phase genny thanks for any advice given paul

Any generator over around 5kva will be 3 ph, all hire sets come as self contained units with a multitude of 1ph and 3ph outlets from 16A to 63A AND 125A in larger sizes. Best go to a reputable hire firm and tell 'em your requirements.

 

[Knobhead]

Send Rockingit a PM.

The one person I'd recommend for a job like this.

 

[davethsparky]

Call a company who deal with event power, its not a simple as picking a generator based on the numbers.<br><br>Temporary power distribution for events is a world I work in a lot, I've seen a lot of very scary stuff which is ridiculously dangerous.<br>

<br>How did you arrive at a figure of 41KVA? how much diversity did you allow in this? and how much contingency? You need to consider that an underloaded generator can get quite grumpy. And you have to get your loads balanced properly across the three phases or else you can wreck the voltage regulator on the generator, generally you need to get the balance within 30% but you'll need to check the specs.&nbsp;<br>

<br>You'll need to consider how you are going to keep it fed with fuel, don't forget to carry a spare fuel filter if you're buying your red from a local farmer.&nbsp;<br>

<br>You will need to think about the earthing system as you are creating your own TNS distribution system, too many people who have a go at this think they are using TT earthing because earth rods are involved!<br>

<br>Always test and re-test a hire generator, its not unheard of for them to come out with serious polarity issues. Discovering you have 415 volts between live and neutral the hard way will be quite destructive!

 

[singingfraggle]

41kva is the calculated load from the data supplied by the customers using the stands. I was going to go over board on the generator by 30 amps in case of emergency . I was not going to in to this blind my concern was not making a fool of myself when talking to the company and asking for something that I did not need or existed . thanks for your concerns dave and all will be taken on board

 

[davethsparky]

The best thing to do is go to an event power company or generator company and give them an honest account of the loads you are expecting / have been told about. They will be able to advise you on the best size generator and help with distribution if necessary.
The chances of the load on your generator ever getting close to the quoted 41KVA is pretty minimal, you will get to see first hand just how big an effect diversity has.

You will also get the customers not having a clue about what power they need, you'll have some working it out based on a plug being 13amps therefore they have 10 plugs so need 130amps to feed their various laptops and little twinkly display things.
And then you will get the catering department! they tell LIES, we've all been caught out by the 'we only need 13 amps as all our cooking is done on gas' line. Turns out they were planning on plugging a couple of tills, 3 3 KW tea urns, a freezer truck and a couple of massive kenwood food mixers into their 13 amp socket!

Are you providing site lighting for the event? If you are festoon fitted with normal filament lamps is a great way of getting a steady balanced baseline load to give the generator a chance of fighting against other constantly fluctuating loads.

Last festival I did we had someone flash a bunch of 1500watt strobes at full power before I had any ballast load on the generator, the poor thing damn near stopped turning! The backup generator started up and came online but both the lighting control desk and the digital sound desk weren't very happy about the situation.

 

[JD6400]

Dave , just one word in that post summed it up = CATERING !!!! :censored:

 

[davethsparky]

Oh yes, don't you just love them?

"we only need 1 socket" yeah one 125A 3ph

"we've got all our own distro" oh no you don't bring that anywhere near my site or I will apply petrol and a match

"its all been PAT tested, look we have a certificate" sorry, looks like the emergency spare bogroll to me.

"Sorry we poured boiling oil all over your big distro and cables, will it be ok?"

"What do you mean you cant just change the 16A single we asked for for the freezer truck to a 32A three it actually needs?"

 

[JD6400]

They are the single biggest drain on my time and nerves when doing events be it a small wedding or a country show ! With the craft stands coming a very close second , if it isn't screwed down then they see it as fair game , I tend to find !

 

[davethsparky]

Oooh, I see your craft stands and raise you the fun-fair people!

 

[JD6400]

Now , I always say that a man should know when he is beat ! So with that I must respectfully bow out , for you sir have just shown no mercy !

 

[davethsparky]

I wonder what they all say about us grumpy sparkys?