Running power 4000 feet

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They aren’t rods at each joint. I’ve pinched an idea off the DNO’s, an earth tape from the cable armouring buried alongside the joint.
A true PME system not to be confused with CNE which you use.

What I’m doing falls outside the scope of BS7671, it comes under BS7430-2011-COP.

Terminating the cable is no different to normal SWA except the length of the tails need to be longer and dressing the cores so they don’t have sharp kinks (corona discharge). The UG joint boxes are just large sized ScotchCast kits but I won’t use mechanical connectors, I’ll solder them with a ferule.

This job is designed to outlast me (that’s not a very good guarantee)
 
Mbrooke, what option did you end up going with? Was the customer happy???


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Tony S said:
They aren’t rods at each joint. I’ve pinched an idea off the DNO’s, an earth tape from the cable armouring buried alongside the joint.
A true PME system not to be confused with CNE which you use.
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:?:dunce: What is the difference between CNE (combined neutral earth) and PME?



What I’m doing falls outside the scope of BS7671, it comes under BS7430-2011-COP.
Click to expand...

What voltages does BS7671 cover?

Terminating the cable is no different to normal SWA except the length of the tails need to be longer and dressing the cores so they don’t have sharp kinks (corona discharge). The UG joint boxes are just large sized ScotchCast kits but I won’t use mechanical connectors, I’ll solder them with a ferule.

This job is designed to outlast me (that’s not a very good guarantee)
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Post pics! :D
 
mbrooke said:
:?:dunce: What is the difference between CNE (combined neutral earth) and PME?

Permanent Multiple Earth = no connection to neutral.
Continuous Neutral Earth = neutral connected at each joint and service drop

What voltages does BS7671 cover?

<1000v AC 1500v DC


Post pics! :D
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The bloody place hasn't got off the drawing board yet!
 
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Tony S said:
The bloody place hasn't got off the drawing board yet!
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You know what I mean! :p:) Post pics when done or while in construction.


Our systems might actually be PME since the MGN on the poles is grounded a minimum of 4 times per mile, usually more.
 
mbrooke said:
You know what I mean! :p:) Post pics when done or while in construction.
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Because I’m raising the voltage to MV the transformer needs a separate brick built structure. That has now got to be added to the architect’s plans.

I’d prefer it to be about 20m from the house and then run UG with 250V 25mm² 3c SWA to the main building. The supply end is in a 433/250V switchroom so no problems there.

Work can’t commence until late spring so I’ve plenty of time to sort the details out.
 
Tony S said:
Because I’m raising the voltage to MV the transformer needs a separate brick built structure. That has now got to be added to the architect’s plans.

I’d prefer it to be about 20m from the house and then run UG with 250V 25mm² 3c SWA to the main building. The supply end is in a 433/250V switchroom so no problems there.

Work can’t commence until late spring so I’ve plenty of time to sort the details out.
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Still, in 8 months pics :p:):)

Anyway, they dont have pad mounted transformers in the UK? Here in the US this would be done in pads, which would eliminate the add-ones.

Pad mount:

https://www.google.com/search?q=pad...XYRw7iKEYh25ceiezQT&q=pad mounted transformer
 
This is a quality install, I wouldn’t even suggest monstrosities like those things.

Yes we do have pad mounts, I’ve used a number of them. They come complete with MV and LV switchgear on a single skid unit.

I put a new supply into this 800KVA unit in 2013

IMG_0018C_zps611c7c0c.jpg

17A_zpsf4874ce0.jpg
 
Tony S said:
This is a quality install, I wouldn’t even suggest monstrosities like those things.

Yes we do have pad mounts, I’ve used a number of them. They come complete with MV and LV switchgear on a single skid unit.

I put a new supply into this 800KVA unit in 2013
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Here in the US the utilities have sufficient clout that pad mounts can be found in all sorts of otherwise pleasant landscaped spaces.
Seldom customer owned except occasionally in industrial/commercial.
 
This isn’t a power company job but the owner of the property would never agree to a tin box. To be honest, given the location I wouldn’t want one nearby. The 20m distance will muffle the sound of the transformer and gets around numerous regulations regarding fire and restricted access to the MV side.


We put a new 2x500KVA packaged substation at a remote location in a national park.

The park planning board went mad at us. We had to build a stone clad, slate roofed building around it, I’ll admit it did look an eyesore.

UK national park planning boards have the power of gods. If they say jump, you ask “how high”. I’ve fallen foul of them several times, I’ve never won, it’s easier to give in before the fight starts.
 
Strange, pad mounts around here are usually all but silent and as far as hiding them, bushes work great.

One of the homes my parents owned had a small one that supplied their home and the neighbors. Mom built a garden around it and you would never no it was there.
 
iwire said:
Strange, pad mounts around here are usually all but silent and as far as hiding them, bushes work great.

One of the homes my parents owned had a small one that supplied their home and the neighbors. Mom built a garden around it and you would never no it was there.
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But in a national park you are not allowed to plant a garden in very many places if at all!
 
iwire said:
Strange, pad mounts around here are usually all but silent and as far as hiding them, bushes work great.

One of the homes my parents owned had a small one that supplied their home and the neighbors. Mom built a garden around it and you would never no it was there.
Click to expand...

The pad mounts may be silent, they aren’t if you’re over a mile from the nearest habitation.

Plant a garden ;-) Your feet wouldn’t touch the floor on the way to court.

The only reason we got away with the new substation was we had river water abstraction licences from before the national park was created. The existing substation and pump house dated from the 1930’s and were falling apart so something had to be done with them.
 
Tony S said:
I put a new supply into this 800KVA unit in 2013

IMG_0018C_zps611c7c0c.jpg

17A_zpsf4874ce0.jpg
Click to expand...
Is that normal for distribution in your country? Those look like submersion-rated network transformers? That would be wicked fancy for a simple radial setup in this country.
 
iwire said:
Strange, pad mounts around here are usually all but silent and as far as hiding them, bushes work great.

One of the homes my parents owned had a small one that supplied their home and the neighbors. Mom built a garden around it and you would never no it was there.
Click to expand...
That's so funny to me. My BIL, who is a lineman, just moved to a new house. We went for a visit. Right in the front yard is a pad mount. I asked him, "Did you buy this place just because of this cool yard ornament?"
 
big john said:
Is that normal for distribution in your country? Those look like submersion-rated network transformers? That would be wicked fancy for a simple radial setup in this country.
Click to expand...

They are used on a ring that has two feeds. The ring has an open point so if a section of cable fails it can be switched out and the ring re-jigged to maintain supplies.

There’s actually six switches in the MV unit. The LV side is a MG SAFIF unit, one of the safest types I’ve worked on.

Layout_zps6b3ba164.jpg
 
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