SY Flex Earthing

[whazza22]

Hi

Been told by my tutor that you do not need to use a banjo when using SY Flex as the braiding is an earth.

But If im wiring for a DOL motor/starter for my AM2 then surely it would need an earth?

We have been told to use P-Nut Lock Nuts for the SWA, so would you use the same?

 

[Guest123]

If your tutor insists on you earthing it then ask him for the prorper CXT glands for SY cable.

IMO the braid should be supp bonded ragrdless.

 

[benji]

Most sy iv,e used has it,s own earth core

yours benji

 

[whazza22]

Yeah we use the CXT glands with the two slots.

So if there is a separate earth then I just use a normal lock ring, but if there is not a separate earth then I need to use a banjo??

 

[ian.settle1]

If that is the case why is it that gland kits have a banjo tag in them?

 

[whazza22]

If you use a fly lead even if there is a separate earth, would you connect the fly lead into the same earth terminal as that earth or into the bonding terminals?

 

[Guest123]

If the cable incorporates a dedicated CPC as one of the cores, then simply earth the braid at one end as you would an SWA and terminate the flylead into the same terminal as the circuit CPC.

Terminating it into a spare bonding terminal wouldn't be wrong though either IMO, as long as it was clearly identified as we do with water, gas etc etc.

 

[whazza22]

Would you use the same CPC size as the earth incoporating in cable, or next size down?

 

[whazza22]

incorporated*

 

[Guest123]

Technically it's a supp bond so a 6mm conductor would be ample.

 

[SirKit Breaker]

I take the braiding in through the stuffing gland with the cores, twist a load of it together and crimp it, then connect it to the earth with the earth lead.

 

[whazza22]

Would that be same for 6mm armour and 2.5 SY flex?

 

[ant]

how do u properly terminate sy flex its for me am2 ive got the the the 2 slooted glands but don't know wot to do with the armoured shithing?

 

[TPES]

Not used much SY to be honest, but just wondered if the armouring was earthed would it require RCD protection? Just as it's not necessary for SWA in some cases

 

[malcolmsanford]

Not used much SY to be honest, but just wondered if the armouring was earthed would it require RCD protection? Just as it's not necessary for SWA in some cases

To be honest I have never used SY cable as part of a fixed installation. Where I've used it it as always been to couple accessories or motors up to the fixed installation. It was really used as a flexible cable but becasue of it's contruction it can be used in quite hostile enviroments in heavy commercial and industrial.

I suppose if you wasn't using the SY braiding as the CPC and only as an exposed conductive part then it would not need to be RCD protected.