Pig tailing Paired screened cable

[Jamzie]

It is due partially due to our control schemes and due to cable runs picking up induced voltages even with screened cables

Are the screened cables earthed at both ends?

 

[bomjac]

Could be an issue with support of the cable (or rather lack of) where it enters the rotork. I have known some companies specify that there must be a cable support no more than 6" from any gland. If you are on water works you potentially have issues with condensation or even plain old water entering through a deformed outer seal on the gland.

The weight of the pigtail can deform the outer seal to cause this if it is not supported.

It is up to commissioning to show you exactly why it is not allowed or else your friend should put in a query to engineerng asking them to clarify. If your friend has installed.to spec the it is up to the client to instruct you to remove them all and gland direct. If it is not to spec then the installers have a major headache if it comes to re gland in and testing everything.

Very often "preferential engineering" wil be sought by the inspection team rather than the agreed contractual minimum.

 

[shanky887614]

Could be an issue with support of the cable (or rather lack of) where it enters the rotork. I have known some companies specify that there must be a cable support no more than 6" from any gland. If you are on water works you potentially have issues with condensation or even plain old water entering through a deformed outer seal on the gland.

The weight of the pigtail can deform the outer seal to cause this if it is not supported.

It is up to commissioning to show you exactly why it is not allowed or else your friend should put in a query to engineerng asking them to clarify. If your friend has installed.to spec the it is up to the client to instruct you to remove them all and gland direct. If it is not to spec then the installers have a major headache if it comes to re gland in and testing everything.

Very often "preferential engineering" wil be sought by the inspection team rather than the agreed contractual minimum.

sorry but screened cable like this for sensors etc will be say 0.75/1mm. a small pigtail wont deform the right sized gland/stuffing gland.

 

[WaterSparky]

Bit late guys, but thank you for the replies none the less! I`m not sure what size rotork it was ( Ill talk to him) I find the pigtails are useful when Mechanics are changing out faulty valve etc so it frees up an ICA/Elec. For me its not so useful but as some are in awful places and allows me to wire it up prior to placing on the valve. Each to their own, we have our on standards in-line or succeeding the WIMES standards. But I'm unsure if this will come into it at all.

Edit: In reply/support like Shanky says these will only be 0.75mm2 2 pair or 2x0.75mm2 1 pair so doubtful it will deform, and the supply to the rotork

Thanks guys
WS