high voltage 15kv

[glen1]

i work as an electrical estimator and foreman for a electrical company in winnipeg manitoba .one of our customers require some work done to there cable tray system which currently resides at about 3 feet off the ground .the proposal is to add a second tray alongside the first tray which will carry high voltage wiring (15kv) and low voltage wiring (600v)ac. in using the same tray for both high and low voltage a barrier would have to be installed according to sec 36-100
(3).a couple of concerns can we run a tray with high voltage this close to the ground and also i believe i will have to cover the tray but i can't seem to find a code rule also there is a chain link fence really close to the tray will this or should this be bonded to ground.any suggestions .I have a call into my local inspection dept.first time post long time reader
Thanks

<font color="#a62a2a" size="1">[ May 14, 2004 03:12 PM: Message edited by: glen1 ]</font>

[Tony Moscioni]

Glen1,

I hope this helps . . .


Question #1

Rule 36-100 Conductors

(2) Except as permitted in Paragraphs (1)(b), (1)(c), and (1)(d), conductors used indoors or attached to buildings outdoors shall be:

(d) Type TC tray cable installed in cable tray in accordance with Rule 12-2204.

(3) High-voltage type TC cables shall not be installed in the same cable tray with low-voltage conductors except where the high-voltage TC cables are separated from the low-voltage conductors by a barrier of sheet metal not less than 0.0528 inch thick (No. 16 MSG).

Intent for Rule 36-100

Subrule (2) specifies how conductors used indoors, or attached to buildings outdoors, should be installed. The CE Code, Part I, makes exceptions for high-voltage conductors installed in electrical equipment vaults and Type TC tray cable installed in cable trays as per Rule 12-2204.
Subrule (3) allows high-voltage TC cables in the same cable tray as low-voltage conductors when they are separated by a No. 16 MSG metal barrier.

Question #2

Rule 12-2204(2)

Type TC tray cable shall be permitted in cable trays in areas of industrial establishments that are inaccessible to the public provided the cable is

(b) Provided with mechanical protection where subject to damage either during or after installation;


Intent for Rule 12-2204(2)

(b) provided with mechanical protection where subject to damage either during or after installation. Protection may be by elevation, by the use of covers, shields, or by other acceptable means. Consideration should be given to possible damage from falling or movable objects, access by persons not qualified, and high-temperature conditions from radiant heaters; and

(c) not smaller than No. 1/0 AWG, copper or aluminum, if single conductors are used. The No. 1/0 AWG size limitation is related to mechanical forces to the tray under fault conditions; and

(d) installed only in areas of industrial establishments where qualified persons are available to service and maintain the system.


Question #3

Rule 36-308 Connections to the Station Ground Electrode
(see Appendix B)

(1) All non-current-carrying metal equipment and structures forming part of the station shall be grounded to the station ground electrode to prevent the build-up of dangerous potential differences between the equipment or structures and the nearby earth.

The non-current-carrying parts of metal equipment such as cable sheaths, potheads, raceways, pipe work, screen guards, meters and instruments, and exposed metal work on buildings shall be grounded to the station ground electrode. The purpose of Subrule (2)(e) is to keep the touch voltage to a minimum.


Tony Moscioni
Electrical Inspector
Electrical Safety Authority

[glen1]

Thanks Tony for your quick response your answers do help