Generator on Farm

[Guybrows]

Hi

Had a phone call to go and look at moving a 44kva 3 phase generator on a farm. Im going to have to resupply it in swa. I havent done any work on a farm and i ve only ever installed temporary generators when the electricity board have decided not to turn up a day before a shop opens. I am thinking i should bury the cable 0.6m as per regs. Does anyone know if it has to be bureied. The guy on the phone was talking about taking it over a building but i want it to be done to regs. Any other advice would be greatly appreciated

Thanks guys

 

[needasparks]

There is no reason it has to be buried other than if you do it should be deep enough that it will not be damaged hence the recomended depth of 600mm or if it is going surface it should be placed where vehicle or livestock damage will not happen, However from past experience on farms I would think carefully on the route underground as layouts change contantly with fenceposts etc.
Best advice is to keep to straight lines with solid markers (buildings etc) at direction changes, go deeper if you can and give them a layout drawing to stop damage to it later not forgetting marker tape above its route.
My guess its for a standby with auto or manual changover so earthing should also be checked but i'm sure you have that covered.

 

[poppypiesdad]

BUY WELLIES , that is all

 

[needasparks]

BUY WELLIES , that is all

you win Quote of the day

 

[Marvo]

The guy on the phone was talking about taking it over a building

Not sure I like the sound of that. What exactly is 'over' a building?

 

[Guybrows]

I dont know Marvo, but i didnt like the sound of it either.​

 

[Marvo]

Lol, I'd rather stick to terra firma if I were you.

 

[JD6400]

If going across productive land then we go at least one meter deep .

 

[Knobhead]

Don't forget to earth the generator properly!

View attachment 9004

 

[johnboy6083]

when you eary your genny, try to get a low reading as possible.This will entail driving 2 or more seperate rods down, at least the same distance as the deepest rod apart. Also any metalwork that can be touched at the same time as the genny frame, will need to be bonded to the genny.

 

[JD6400]

Don't forget to earth the generator properly!

View attachment 9004

If i could not see the pipe in the background then i would have bet me lot that was a finished farm install !
That is true ingenuity for you .

 

[Knobhead]

That is true ingenuity for you .

Only in America!

 

[UKMeterman]

It says 240V on the photo..

 

[JD6400]

It says 240V on the photo..

Thats what i mean !
To read the instructions on how to start it they must have finally learnt how to read the Queen's English !:ciappa::79:

 

[Engineer54]

when you eary your genny, try to get a low reading as possible.This will entail driving 2 or more seperate rods down, at least the same distance as the deepest rod apart. Also any metalwork that can be touched at the same time as the genny frame, will need to be bonded to the genny.

Far better to have one rod position and coupling the rods to give you the depth, rather than having 2 X 1 metre rods in 2 positions. Even better, to have the 2 rod positions each with 2 rods coupled together!!

What is important is to make absolutely sure your neutral point on the Genny is earthed via your rods, and not just bonded to the Genny frame.

 

[johnboy6083]

Far better to have one rod position and coupling the rods to give you the depth, rather than having 2 X 1 metre rods in 2 positions. Even better, to have the 2 rod positions each with 2 rods coupled together!!

What is important is to make absolutely sure your neutral point on the Genny is earthed via your rods, and not just bonded to the Genny frame.

When I said rods, I meant that a number of rods screwed together still constitutes one complete rod. I wouldn't advise only sinking one length.

 

[Engineer54]

When I said rods, I meant that a number of rods screwed together still constitutes one complete rod. I wouldn't advise only sinking one length.

Glad to hear that...lol!! I'm afraid i take all rods, to be these 1 metre things in the UK these day's... lol!!!

 

[Engineer54]

When I said rods, I meant that a number of rods screwed together still constitutes one complete rod. I wouldn't advise only sinking one length.

What i tend to do when supplying a TT earth for permanent and semi-permanent Genny's of a smaller size, is to position my earth rods diagonally approx a metre or so away from the the Genny mounting pad and run a 16/25mm bare copper conductor around the pad at around 50 to 60cm depth, linking the 2 rod positions.


Also, if the pad is substantual, with decent reinforcment, i'll also make arrangements to have to a section of rebar brought out of the pad and connect that to the earth ring. Or connect a short length of insulated earth conductor to the rebar prior to the concrete pour.

For larger stand-by, and prime power Genny's (750 KVA and above) the earth arrangement will be obviously be a good deal more involved but still based loosely on the above arrangement...

As i've stated before, i'm far more used to working with 3m 3/4'' earth rods, but nothing stopping anyone in the UK from coupling together 2 or 3, 5/8'' rods to get the depth, stability and decent Ra value

 

[Guybrows]

Had a look today and looks easy enough to run the cable using gurder clips to run the cable up and across along the steel frame of the milking parlor.

Going to do my cable calculations to get correct cable size.
The Generator(44kva) will be sitting on a concrete pad that has already been built and will be fixed down.
Where the generator is currently situated it has a bond from the frame to the steel structure of the building.

Am i correct in assuming that,

1. I will need to bond the frame of the generator to the steel frame as you can touch both at the same time

2. An earth spike shall be installed and connected to external earth connection on the frame of the generator and then check continuity between earth point and neutral connection at the generator.

3. Does the above then give me a pme at the cu that the generator is feeding thus i have no need for an earth spike at cu or the running of a separate earth from generator to cu, i'm guessing i should then do a ze at cu and get less than 20 ohms.

4. The cu has two supplies connected. the permanent generator that is getting moved being one and they also have a smaller generator that they use as a back up if the permanent generator goes down. Theoretically this allows for both generators to be supplying cu simultaneously. Is this allowed?

5. Does the installation need rcd protection or does it now become a pme/tncs system?

Thanks for all your help guys, really enjoying this one as its all new to me!

 

[poppypiesdad]

Can we get some piccys , when your not busy during the install


I would say that unless the two gennys can be synchronised then it would not be allowed , could be wrong ,
JAmie