Earth Bonding

[davebargh]

Hi all,
My first post-don't be too hard on me!
I'm bonding an existing 3-phase power supply (150mm2 SWA cable) to various incoming services: Sprinkler main, water, compressed air, gas steam & condensate etc. According to BS7671, I can run 35mm2 wire. The run to first service from main earth terminal is about 25m but once there, services are max. 2m apart.
Is it allowed to crimp 2 x 35 wires into say a 70mm crimp ring connector to jump from service to service? Although the conductor is cut, it is permanently joined together. Could even run solder into crimp terminal.
The other issue I have is connecting such a large lug to 15mm copper pipe clamp(s). There is no mention in regs. about possibility of an auxiliary earth terminal, then radiating out from such a terminal separately to each service. This would save so much wire.
Regards
Dave

 

[telectrix]

I would use 2 x 35mm lugs. the cable does not need to be unbroken. just continuous. which it will be once the 2 lugs are bolted together.

 

[R-fur]

I would consider using an earth bar. Run the 35mm from the MET to the bar, then take a single 35mm to each service.

 

[DefyG]

Auxiliary earth terminal (or as per #3) 'earth bar' is permitted and labelled accordingly.

 

[Zerax]

I'd crimp a 35mmsq cable into an tubular terminal that's designed for 35mmsq cable... then bolt together as Tel says or bolt to a busbar etc. Shovin' 2x35mmsq into a terminal that's designed for 70mmsq cable is not a good idea. There are terminals designed for 2 cables, but again they are designed for the task and will require special crimp die sets.

Also, a properly crimped terminal shouldn't have any room for any solder to flow into it. If there is, it's not properly crimped.

...MHO of course.

 

[davebargh]

Auxiliary earth terminal (or as per #3) 'earth bar' is permitted and labelled accordingly.

Thanks for that. Logically makes sense.

 

[Petej999]

Hi all,
My first post-don't be too hard on me!
I'm bonding an existing 3-phase power supply (150mm2 SWA cable) to various incoming services: Sprinkler main, water, compressed air, gas steam & condensate etc. According to BS7671, I can run 35mm2 wire. The run to first service from main earth terminal is about 25m but once there, services are max. 2m apart.
Is it allowed to crimp 2 x 35 wires into say a 70mm crimp ring connector to jump from service to service? Although the conductor is cut, it is permanently joined together. Could even run solder into crimp terminal.
The other issue I have is connecting such a large lug to 15mm copper pipe clamp(s). There is no mention in regs. about possibility of an auxiliary earth terminal, then radiating out from such a terminal separately to each service. This would save so much wire.
Regards
Dave

Fit a local Earth bar and bond all your services to this bar, make sure the Bar is labeled as a bond connection.