Water and gas Bonding on three-Phase

[rosewood]

Hi All, Doing a big remedial job on a factory and changing main incoming tails to 240mm. On inspection found there was no bonding to water and gas. Surely that doesnt mean i need 60mm bonds? also does the clamps HAVE to be bonded next to the incoming water and gas meters or is there a 'get out clause' where you dont have to do it?? If so this could end up being a 60metre run :saddam:

Thanks in advance

 

[Guest55]

They are lime kilns. The pipes you can see are mainly gas.

My old workshop is the open door with the red sign above it in the bottom RH corner.
It’s 20+ years since I crashed the land rover in to the door, it’s still got the steel straps I put across the back to hold it together!
The 11KV substation is on the roof.

The place looks a death trap , just pray i dont do the PIR for it lol.
only kidding

 

[Knobhead]

The place looks a death trap , just pray i dont do the PIR for it lol.
only kidding

It’s covered by M&Q statutory testing. So don’t worry, you won’t get the call.

What do you mean a death trap? It was perfectly safe if you knew what you were doing.

When I started on the plant all the switchgear was 50+ years old. Hidden in it’s heart are six new transformers (total 5.5MW) and boards along with seven new sub boards (400 or 630A feeds to each). Fourteen new MCC panels, (over 600 drives). I became a dab hand at making off 195mm or re-making .3” paper leads. Some of the time it was like trying to keep a museum running. You had to be inventive with some repairs, spares? What are they?

I enjoyed myself there. It was an absolute s**t hole but still fun, I stuck it for 23 years.

 

[Knobhead]

If you did get a contract to do a PIR, you’d be passing on to you successor before you’ve finished.

 

[Ponty Massive]

I'm just thinking outside the box here.....When running bonding to gas and water it's permisable to use one cable and link the two providing there is no break in the cable. By connecting your bonding to the steel work and then again connecting the steelwork back to a bonding cable to connect to the services, are you not effective doing just this?

 

[GaryM]

Nothing wrong with a break in a bonding cable. You could bond to gas with an eylet crimp at the termination then continue with another to the water.

 

[Ponty Massive]

Nothing wrong with a break in a bonding cable. You could bond to gas with an eylet crimp at the termination then continue with another to the water.

I agree totally, but a crimp would be considered a perminent connection. How would you connect the bonding to steel work using a perminent connection?

 

[GaryM]

Use an eylet crimp again and secure either by nut and bolt or tap a hole into the steel. 10mm tapped hole and a C10 eylet would provide a good connection.
Oh, and don't forget the safety electrical connection, do not remove label!

 

[spark 68]

The main reason for the bonding conductor being continuous if only one is used, is so if you disconnect one temporarily for maintenance you don't lose both if it is put back incorrectly, or not put back at all.

I suppose a crimped one fulfils the same requirement, also if structural steel is used I suppose you would have either individual local conductors to each service, or a single one crimped as above, same requirements apply.

 

[Ponty Massive]

By linking the gas and water using your method, you could effectively remove the bonding tag from the first services and keep continuity to the second; (I would point out however, I would still not break the connection and use lugs, but instead strip the pvc and connect in / out to the first tag to ensure continuity to the second should anything happen to the first)

By using the steel structure method, you will not get continuity to the service should the bonding to the steel be disconnected / damaged?

 

[GaryM]

There's a warning notice against removal, and damage, well, that can happen anywhere in any installation but if you're sensible in where you make the connection then the risk can be somewhat less.

Its only the same as the initial bonding of the structural steel.

 

[spark 68]

By linking the gas and water using your method, you could effectively remove the bonding tag from the first services and keep continuity to the second; (I would point out however, I would still not break the connection and use lugs, but instead strip the pvc and connect in / out to the first tag to ensure continuity to the second should anything happen to the first)

By using the steel structure method, you will not get continuity to the service should the bonding to the steel be disconnected / damaged?

That's exactly what I meant, both cables crimped into a single lug, whether cut or not will still be continuous if crimped together.

Well removing any bonding conductor for any reason carries this risk, we can only put the safety connection tag on, and hope whoever does the removal put's it back correctly.

 

[Ponty Massive]

Ahh, I see. Make sense!! (About the two cables into one lug)

 

[Ponty Massive]

Well removing any bonding conductor for any reason carries this risk, we can only put the safety connection tag on, and hope whoever does the removal put's it back correctly.

This is the part that does not sit well for me. This would be the equivellent of running a bond to your water pipe, then putting a second 951 tag on the same water pipe and running it to the gas?

 

[spark 68]

This is the part that does not sit well for me. This would be the equivellent of running a bond to your water pipe, then putting a second 951 tag on the same water pipe and running it to the gas?

I was referring to the second part of your post here, with respect to the bonding conductor from the MET to the structural steel, and I hear what you are saying here, I suppose this would in effect be two or more connections, one at the MET end, and one or more at the services end.

I suppose it would require a risk assessment, but as others have said it seems to be industry standard.

 

[Risteard]

Table 54.8

> 150mm, bonding has to be 50mm, and <= 0.05 ohms

The 0.05 Ohms thing is mentioned in Guidance Note 3 for proving continuity but is not actually a requirement and has been taken out of context.