Piha Generators during September storm

[treybolinger]

Amazing that this is just a big engine that is making all the power. Two things I like, nerdy engineering, and automotive technology.

[ChumpusRex]

Are these low voltage generators connected to the transformer secondary? Or are the big ones medium voltage?

At work, our backup generators are all 11 kV - except for 2 'oh crap' backups which are 400V and used for secondary backup for the most critical areas.

[frazzledude]

I have a question. When you connect these hired generators to the electrical grid, how do you know the rotation/phase order is correct? It seems to me that there is a 50/50 possibility that all of the 3 phase motors powered by these generators could start up turning the wrong direction. Is there a standardized order for the three phases in the New Zealand electrical distribution system?

[RODALCO2007]

@frazzledude Good question. This location has frequent power cuts and the phase rotation is known and marked in the connection points.

The phase rotation is normally clockwise at the generator terminals and is checked prior to livening.

In genral the phase rotation should be clockwise for R-Y-B or A-B-C or L1- L2- L3 but on many transformers there is a 50 / 50 chance that it is wrong.

[frazzledude]

@RODALCO2007 Okay. That makes sense. Thanks for the answer.

[Nivicoman]

I take it that those diesel prime movers are ok with spinning up to 1500 rpm right away instead of having an idling/warmup period?

[RODALCO2007]

@Nivicoman The big 12 and 16 cylinder engines usually get a 10 minutes warm up with no load before the braker is closed.

[BarneySaysHi]

Man I love the sound of those big engines starting. Where I used to work we had 4 backup generators, 2 MW each. They were heated day and night so they could deliver their power instantly. Datacentres, gotta love them for big generators.

[RODALCO2007]

@BarneySaysHi We ran these generators for 15 minutes prior to loading them up.

In this emergency case they were started cold, ran with no load for about 15 minutes and then the load was applied. In the day part of the video's we had 2 trips as the impedance + load were to high and the over current protection kicked in.

3 rd time it held after part of the 11kV load was switched off by means of an isolator switch 1 kn away.

[epd807]

More great video! Thanks Ray!

[btown2011]

very very cool video, thank you for posting

[HDXFH]

love those cranking sounds, really hear the starter gear turning over the flywheel

[RODALCO2007]

@HDXFH That big V16 generator has two 24 Volt starter motors and two 24 Volt battery banks.

[ihatespam1977]

My electrical utility would never supply customers temporary power via a generator. They'd simply say tough luck and let customers sit in the dark for however many hours/days needed.

[RODALCO2007]

@ihatespam1977 In NZ they care about their customers.

[stdavross666]

@ihatespam1977 common practice in australia also. Western power advertises split system ac for years ...so efficient, blaa blaa and then cant keep up with demand. now theres ads on tv telling people not to use there air con. dipshaits.

[teslapower220]

Seems like quite a windy place. You could have wind turbines installed there for power ;)

[TheWelly888]

Why was it clagging? I thought it was supplying a more or less constant load?

[RODALCO2007]

@TheWelly888 At the beginning, the engine is ran at no load for about 15 minutes to have the engine warmed up. When a large load is applied the generator will initially slow down a little, extra fuel gets injected in the prime mover hence clagging will occur for a couple of seconds.

In the morning an other fault caused tripping hence the restart at morning time.

[peterahjorter]

Here in Sweden we had a really bad storm a couple of years ago and after that many powercompanies started to dig their cables down

[cortexedge]

This shows how dependent we are on electric energy!