earthing SWA glands

[sharpe]

Hi, i would like to make sure i understand this properly.

On a TNS supply, using 3 core SWA to run a sub-main, and using the third core for CPC, where the SWA gland terminates into a plastic enclosure, how is it best to earth the armour?

Am i right that you run a fly lead (the same size CSA as the live conductors) from the banjo/piranha nut, back to the MET?

Or do you run a bonding conductor from the banjo/piranha nut, to the earth terminal inside the enclosure the gland is terminating into?

Or can you do either

Thanks

 

[bernardgreen]

Untitled

• bernardgreen
• 10 May 2009
• 17

is one way though it would have been better if I had used a banjo as well, and a grommet where the cores pass out of the box and into the CU

 

[Risteard]

You will need to use a banjo sandwiched between two locknuts if terminating into a plastic enclosure so that the plastic creeping won't affect your connection.

I'm not sure why you refer to a "bonding conductor" as we are discussing earthing which is a completely separate thing.

As for the csa of the flylead you will have to work that out.

 

[JohnW2]

You will need to use a banjo sandwiched between two locknuts if terminating into a plastic enclosure so that the plastic creeping won't affect your connection.

Or use a piranha nut?

Kind Regards, John

 

[Risteard]

You will need to use a banjo sandwiched between two locknuts if terminating into a plastic enclosure so that the plastic creeping won't affect your connection.

Or use a piranha nut?

Kind Regards, John

You could, but I see no reason not to use proprietory SWA glands without purchasing an unnecessary new type.

 

[JohnW2]

Or use a piranha nut?

You could, but I see no reason not to use proprietary SWA glands without purchasing an unnecessary new type.

I can't actually recall ever have seen a 'proprietary swa gland# which came with a spare nut, so one would have to purchase that, anyway (unless one already had one). The other advantage of piranha's on plastic boxes is that, by gripping onto the box with its teeth, they reduce the risk of the whole gland coming lose (relative to the box), which might possibly have a detrimental effect on the termination of the armour.

Kind Regards, John

 

[Taylortwocities]

WHy plastic enclosure? Amd 3 is only days away, shouldn't you would be installing a metal enclosure?

 

[sparkwright]

WHy plastic enclosure? Amd 3 is only days away, shouldn't you would be installing a metal enclosure?

I like to think the plastic enclosure is either an existing consumer unit, or some kind of adaptable box or socket.

 

[333rocky333]

The other advantage of piranha's on plastic boxes is that, by gripping onto the box with its teeth, they reduce the risk of the whole gland coming lose (relative to the box), which might possibly have a detrimental effect on the termination of the armour.

Kind Regards, John

As you may be aware, the main purpose of the teethed side is to allow easy tightening of the gland from outside without the need for gripping the locknut,the other plain side is for use when tightening of the locknut is prefered.
Though what you say is a bonus.

They should come supplied with a grub screw for use with plastic boxes, to ensure they dont work loose and maintain tightness even in the event of the plastic breaking away

 

[JohnW2]

The other advantage of piranha's on plastic boxes is that, by gripping onto the box with its teeth, they reduce the risk of the whole gland coming lose (relative to the box), which might possibly have a detrimental effect on the termination of the armour.

As you may be aware, the main purpose of the teethed side is to allow easy tightening of the gland from outside without the need for gripping the locknut,the other plain side is for use when tightening of the locknut is prefered.

Indeed so - that is the 'main purpose'.

Though what you say is a bonus.

Exactly - and that was my point.

They should come supplied with a grub screw for use with plastic boxes, to ensure they dont work loose and maintain tightness even in the event of the plastic breaking away

Indeed. In fact, I think I've nearly always seen the grub screw used (and tightened) on metal boxes, as well as plastic ones. Since it's there, that seems sensible, and it's certainly what I do.

Kind Regards, John

 

[Risteard]

Amd 3 is only days away

Actually, Amendment 3 has been in force for over 5 months already. It is only one particular requirement which is "only days away".