Full rcbo boards????

[D00DY_T00DY]

Hi all,

Probably going to seem like a novice question just wondering what techniques you lot have for full rcbo boards to keep it neat.

Put 5 in today for a temporary supply for ground workers on a genny; earth rod with a Zs of 2.13ohms (fairly good?)

Anyway it was a complete nightmare trying to keep it neat with the earth and neutral flexes out of them.

I've only installed less than 10 just wondering all your techniques for rcbos?

I kept all the length on these and tried to coil them nicely behind the cpc and neutral terminals.

 

[hightower]

very neat, mate.

Was done last year for my CPS assessment, looking at it now (a year down the line) and I'd argue there's room for improvement. I think if I'd done it today I'd have learnt a few more tricks and it would be neater still.

Thought I had some photos of a Proteus (absolute s****) 3-phase board I done recently where I'd cut and ferruled but I've checked and seems I didn't bother to get the camera out.

 

[FatAlan]

Where you been HT? Nice pic, how long did that take out of interest? Or is that why I haven't seen any posts for a while!

 

[Ian1981]

I know the kqi Schneider rcbo instructions tell you not to bundle the neutrals together but can cut to length.
They recommend if the functional earth is cut then a bootlace is fitted due to crushing of the fine strands when tightend in the terminals

 

[LankyWill]

My boss used to unwrap the coiled leads and hang them from a table at night. Gives you a nice straight tail then. I always shorten and ferrule, that said the SBS is a good option.

 

[davesparks]

Rcbo tails should be cut to length and not bundled up in the board as this can lead to overheating of the conductor. Some, such as Schneider, even have this detailed in the instructions.

I'm curious about the Zs quoted in the OP, any Zs measurement on a generator fed installation won't include the earth rod, it will be testing the return path directly to the star point of the alternator.
The Ra for generator earth rods has to be measured using an earth electrode testing method.

 

[D00DY_T00DY]

Just how big was that fish again ?
You've beaten my record (6.x Ohms) that's for sure !

The rod was on the other side of the cabin wall if it makes you feel better literally a 4meter run max. That's going down the wall too 1M rod? Wholesalers forgot our spike though so that was fun.

 

[davesparks]

The rod was on the other side of the cabin wall if it makes you feel better literally a 4meter run max. That's going down the wall too 1M rod? Wholesalers forgot our spike though so that was fun.

What method did you use to test the rod?

 

[Ian1981]

I got a Ra of 4 ohms the other day tho I used the structural steel as the electrode.
All bolted together about 10 lengths of steel into the foundations.

 

[D00DY_T00DY]

I know the kqi Schneider rcbo instructions tell you not to bundle the neutrals together but can cut to length.
They recommend if the functional earth is cut then a bootlace is fitted due to crushing of the fine strands when tightend in the terminals

Temporary supply mate, might be in a month max. Probably try blag the company to give him the cable and gear back since they won't use it did on the last tempory supply we did haha

 

[D00DY_T00DY]

What method did you use to test the rod?

Boss does the testing, I took a Zs at the board after I finished. That's what I was referencing

 

[Ian1981]

Temporary supply mate, might be in a month max. Probably try blag the company to give him the cable and gear back since they won't use it did on the last tempory supply we did haha

Wrong post I think mate haha

 

[D00DY_T00DY]

Wrong post I think mate haha

Well you were saying not to bundle them which I did in this instance

 

[Ian1981]

Well you were saying not to bundle them which I did in this instance

Oh yeah my mistake.
I'm just mentioning Schneiders instructions.
Overheating of the neutral was the reason they give me.

 

[D00DY_T00DY]

Oh yeah my mistake.
I'm just mentioning Schneiders instructions.
Overheating of the neutral was the reason they give me.

Wonder if it actually makes a difference or it's just them putting their tin hats on.

Duely noted though.

 

[davesparks]

Boss does the testing, I took a Zs at the board after I finished. That's what I was referencing

Does your boss not include you in the testing process? Did you see him set up temporary electrodes and test the earth rod at any point in time?

Your Zs measurement almost certainly did not include the earth rod. You will have been testing via the cpc straight back to the star point via the N-E link at the generator

With a generator fed installation the earth electrode is the earth reference of your TNS system. In comparison to a normal installation the generator is equivalent to the substation transformer.