The IET is carrying out some important updates between 17-30 April and all of our websites will be view only. For more information, read this Announcement

Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Suggested Answer
  • Locked Locked
  • Replies 16 replies
  • Helpful Answers 1 Helpful answer
  • Subscribers 38 subscribers
  • Views 3160 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Bonding industrial buildings

Sparky gaz

Bonding question 

Our main 2000a dis board is 150meters away from the main incoming water supply .. We presently have a 50mm bonding cable going to a 25mm water incoming supply is this acceptable?..

Also our gas is 15meters away from main dis board . presently has a 50mm bonding going the gas 5" incomer is this acceptable ? in 2016 it had a code C2 put on it during a eicr im about to do a new eicr and just wanted to check as struggling to find much in the regs book about gas about 28mm

Parents
  • 0

    For that size of supply it is going to be a TN-S supply with a separate earth from the Tx. Or may be a TN-C-S (PNB) supply so PME conditions do not apply. So the bonds do not need to exceed 25mm, see Regulation 544.1.1. 

    These protective conductors are all about equipotential bonding although they will carry some earth  fault current most of it hopefully will flow in the CPCs and back to the transformer star point via the earthing conductor.

    Out of interest what was the observation that attracted the C2 code? 

Reply
  • 0

    For that size of supply it is going to be a TN-S supply with a separate earth from the Tx. Or may be a TN-C-S (PNB) supply so PME conditions do not apply. So the bonds do not need to exceed 25mm, see Regulation 544.1.1. 

    These protective conductors are all about equipotential bonding although they will carry some earth  fault current most of it hopefully will flow in the CPCs and back to the transformer star point via the earthing conductor.

    Out of interest what was the observation that attracted the C2 code? 

Children
  • 0 in reply to John Peckham

  • 0 in reply to Sparky gaz

    "Undersized bonds"  maybe not - as we have calculated above.  or have they been up-sized from something thinner., and what you see now is the improved version ?
    It would be unusual to leave a C2 for that long
    Mike.

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines