Steel Awning frame outside EP zone, bondit?

[John-]

Hi

customer had installed a 10m awning that is secured to a very substantial 6” box steel frame, concreted in either end - large goal post if you will. It is fitted on the garden patio, just outside the entrence to his living area accesd by sliding doors. The motor is a low current single phase motor that moves the awning in and out quite slowly. There is no fortuitous or deliberate connection to earth between the motor CPC and the aluminium awning box. A 3 core flex is run on top of the steel work into and RCD socket. I am looking at upgrading the MCB to RCBO. I have no details yet from the manufacturer - i will look to getting these. It is a TNCS supply.

Question is, should i bond the steel work to the motor CPC at lesst? Technically it could be classed as structural. If so it would need a much bigger conductor... Or do i just leave it alone? My call is that this is extranious and should be bonded to the supply of the motor. It is on the threshold between EP zone and simultaneously accessible for both. He wont go for 10mm cable back to dis board, pretty sure he will go ape with a bit of 4mm on show... ?

 

[dodger421]

Have you tested to confirm that it is an extraneous conductive part? You might find it’s not and doesn’t need bonding at all.

Can you touch both the frame and something that might be at a different potential at the same time? Say the awning frame and a nearby, bonded, supply for an outside tap?

 

[John-]

Its 12k today, it’s not an Extranious part today i guess. No other touch points today but there could be. The aluminium housing of the awning is secured directly to the steel. That’s my biggest worry.

 

[dodger421]

The frame can’t be touched at the same time as anything that’s might be at a different potential, so why does it need bonding?

 

[UNG]

Not knowing the layout or positioning of the awning has anyone considered if lightning protection might be needed with all this metalwork

 

[cliffed]

This may be of some help

 

[Cookie]

I can't picture shoes in all cases.

 

[marcuswareham]

Could bonding it present a risk which was not otherwise there due to it being a TN-C-S supply

Risk of metal frame voltage rise difference to the ground around it from a PEN conductor fault, or even tingles from normal PEN conductor volt drop