6.6 KV power Cable joint on open air Cable Tray in Hazardous area
6.6 KV power Cable joint on open air Cable Tray in Hazardous area
(OP)
Good day to you
Our installation is LNG production plant(Oil and Gas)
We have a failure of a 6.6KV power cable near to the equipment located in Hazardous area IEC Zone 2. Planning to cut the faulty portion of the cable and splice it with a short piece ofnew cable.
We are debating on the safety aspect the location of the cable joint since it is inside hazardous area. We prefer to put the joint at the under ground portion of cable route considering cable joint will be the weak point/inside hazardous area, for this minimum 100mts of cable is required. The contractor proposal is to have the joint on the Cable tray with a small piece of cable of 10 mts.
We would request information/ suggestion from the forum on any international standard reference governing the cable joint location inside Hazardous area.
Thanks in advance for your quick input.
Regards
Ramesh
Our installation is LNG production plant(Oil and Gas)
We have a failure of a 6.6KV power cable near to the equipment located in Hazardous area IEC Zone 2. Planning to cut the faulty portion of the cable and splice it with a short piece ofnew cable.
We are debating on the safety aspect the location of the cable joint since it is inside hazardous area. We prefer to put the joint at the under ground portion of cable route considering cable joint will be the weak point/inside hazardous area, for this minimum 100mts of cable is required. The contractor proposal is to have the joint on the Cable tray with a small piece of cable of 10 mts.
We would request information/ suggestion from the forum on any international standard reference governing the cable joint location inside Hazardous area.
Thanks in advance for your quick input.
Regards
Ramesh






RE: 6.6 KV power Cable joint on open air Cable Tray in Hazardous area
In my opinion IEC 60079 series has nothing mentioned about such cable joints.
Whether you follow IEC (Zones)or NEC (Divsions) the main issue is whether the equipment is producing sparks or arcs. In Zone2 or Div2 the probabilty of simultaneous occurence of spark and gas leak is considered.
Therefore, that probabilty is there in Zone2 even with a new cable. Because of that we are not going to have "explosion proof" cables or "explosion proof" motors or JBs in Zone 2.If the cable is specified per IEC 60332, then it is not essential to have it in sand filled trenches.
Based on above, I cannot justify of putting the cable joint underground, because when you make a good joint it becomes a part of the existing cable.Therefore, I agree with above ground jointing.
RE: 6.6 KV power Cable joint on open air Cable Tray in Hazardous area
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: 6.6 KV power Cable joint on open air Cable Tray in Hazardous area
Rafiq Bulsara
http://www.srengineersct.com
RE: 6.6 KV power Cable joint on open air Cable Tray in Hazardous area
A splice in a tray is not much different than a splice on messenger supported overhead aerial cables. I have seen many splices like that within a Class 1 Div 2 location in refinery process areas. (Similar to Class 1 Zone 2).
The cause of the original cable failure might have some bearing on the decision or the type of splice used. Did a local process system spew acid on the cable or was there mechanical damage that could be expected to occur again?
RE: 6.6 KV power Cable joint on open air Cable Tray in Hazardous area
Thanks again
Ramesh