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Hey guys
I have been to numerous cable manufacturers to discuss the correct termination of an ECC cable. It amazes me that not one manufacturer knows how. When looking at the the regulations regarding this there is quite a bit.
Would you agree that the an ECC cable should be glanded off and terminated in the same way as a normal SWA cable would be? We have been told that the copper armoring should run through the gland and connect to the consumers earth bar. Surely if we gland of the cable and the gland connects to the steel enclosure and we use an earth tag this will be sufficient earthing?
This eliminates the need for a separate earth to be installed. Especially in a high crime area.
We have done the PSCC calculations and loop impedance and we are well under the maximum permissible values.
Could one of you gents or ladies enlighten us as to how this cable should be terminated if the above method is incorrect?
Below are parts of the SANS 10142-1 sections that we followed:
6.3.7.3 Any armouring or sheathing shall be terminated in or on
equipment. Armour wires shall be terminated by a clamp or gland in such
a way that
a) pressure is not applied to insulating material, and
b) there is an earth tag washer (or similar) for connecting to the earth
continuity conductor.
6.12.1
NOTE Where the armouring of a cable is used as the earth continuity path, the
resistance of the earth continuity path shall not exceed the appropriate value given in
table 8.1; it may be necessary to replace some of the steel wires with tinned copper
ones or to use a supplementary earth continuity conductor.
M.2.2 – TN-S system earthing
The protective conductor (PE), which is connected to the source earth, is
either a separate conductor or the armour of the cable if the resistance of the
armouring is such that the earth fault loop impedance complies with the
requirements of 8.7.5.
I have been to numerous cable manufacturers to discuss the correct termination of an ECC cable. It amazes me that not one manufacturer knows how. When looking at the the regulations regarding this there is quite a bit.
Would you agree that the an ECC cable should be glanded off and terminated in the same way as a normal SWA cable would be? We have been told that the copper armoring should run through the gland and connect to the consumers earth bar. Surely if we gland of the cable and the gland connects to the steel enclosure and we use an earth tag this will be sufficient earthing?
This eliminates the need for a separate earth to be installed. Especially in a high crime area.
We have done the PSCC calculations and loop impedance and we are well under the maximum permissible values.
Could one of you gents or ladies enlighten us as to how this cable should be terminated if the above method is incorrect?
Below are parts of the SANS 10142-1 sections that we followed:
6.3.7.3 Any armouring or sheathing shall be terminated in or on
equipment. Armour wires shall be terminated by a clamp or gland in such
a way that
a) pressure is not applied to insulating material, and
b) there is an earth tag washer (or similar) for connecting to the earth
continuity conductor.
6.12.1
NOTE Where the armouring of a cable is used as the earth continuity path, the
resistance of the earth continuity path shall not exceed the appropriate value given in
table 8.1; it may be necessary to replace some of the steel wires with tinned copper
ones or to use a supplementary earth continuity conductor.
M.2.2 – TN-S system earthing
The protective conductor (PE), which is connected to the source earth, is
either a separate conductor or the armour of the cable if the resistance of the
armouring is such that the earth fault loop impedance complies with the
requirements of 8.7.5.
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