safety for wiring methods

Safety for Wiring MethodsSafety for Wiring Methods

By : Komarul Fausiyah

Wiring Methods for Construction ...

1. Cable shall be installed in accordance with drawings. The following segregation will be adhered to throughout the facility:

a. Medium voltage power cabling shall not occupy the same enclosure, conduit, duct or tray with 600 volt or less light and power conductors.

b. Conductor of 600 volt or less light and power systems and associated 120 volt A.C. System control cabling shall be permitted to occupy the same enclosure, conduit, duct or tray where all co.

c. Conductors of A.C. and D.C. low voltage instrumentation, control and communication system shall not occupy the same enclosure, conduit, duct or tray with conductors listed above. For detailed description of power/instrument cabling segregations requirements refer to specification VES-7112, section 6.2 thru 6.7.


2. All medium voltage power cabling within the plan production area shall be installed underground utilized an underground duct bank system. For pull boxes and duct bank construction details refer to standard drawing STD-60-07

3. Direct buried cables shall be acceptable for of-plot services and for non essential plant utilities, where such are located outside the production facility boundary. For installation details refer to standard drawing STD-60-06.


4. In general, 600 volt or less in-plant electrical power and control distribution shall be installed in overhead cable tray utilizing tray rated/ armored cables as listed in section 13.2. Cable runs from the tray to the equipment served shall be installed in rigid conduit or via PVC underground duct or shall be properly supported armored cable.

5. For above ground installations, multiples of single conductor wire, and/or multi-conductor cable run in rigid conduit or properly supported armored cable shall be provide for those cases where the cable tray system is not feasible, area lighting and instrumentation field devices.


6. Where metal conduit is used, all phases of a three phase circuit and neutral wire, if any, shall be located in the same conduit.

7. All wire and cable shall be continuous without splices from origin to termination as far as is practicable. Where splices are required, they shall be made in approved junction boxes. No splices or repaired wires or cables will be permitted within conduits between approved junction boxes or pull points.


8. No wire or cable shall be installed which has damaged insulation or jacket.

9. All multi conductor cables shall remain sealed until immediately prior to actual jointing or terminating.

10. The contractor shall not pull wire or cable through boxes or enclosures where a change of raceway alignment or direction occurs.

11. The contractor shall not cut strands from conductors to fit lugs or terminals.


12. The contractor shall not bend cable to less than recommended radius. The minimum cable radius shall not be less than indicated in the following table:Cable Type Minimum Radius0.6/1 KV NYA 5 times OD0.6/1 KV NYY 5 times OD0.6/1 KV NYFGBY 8 times OD3.6/6 KV N2XSY 12 times OD3.6/6 KV N2XSEBY 12 times OD3.6/6/ KV N2XSEFGby 12 items OD


13. The contractor shall employ temporary guides, sheaves, pulley blocks, rollers and other suitable hardware to protect cable from excess tension & abrasion during installation.

14. The contractor shall be ring out each conductor of each feeder for phase identification.

15. Each cable shall be tagged with the cable numbers assigned on the drawings.

Instrument Cable

• In general, armored and unarmored thermoplastic instrument wire, decorum (type :IEB) or equal, 1.5 mm2 twisted single or multi pair overall shielded instrument cable, U.L listed as 300 Volt, 90oC, power limited tray cable, approved for class I, Division 2 classified areas, shall be used.

Splices, Taps and Terminations ...

1) Splices, taps and terminations on 600 volt and above insulated conductors shall be made using crimp type compression sleeves and lugs where possible. The compression fittings used shall be compatible metallurgic ally with the conductor material, and shall be compactable with the wire, crimping tool, and terminal strips. Plated or bare copper body fittings shall be used on copper conductors only. The crimping tool recommended by the fitting manufacturer shall be the one used.


2) The use of bolt-on clamp type fittings is acceptable as a second choice method of splicing, tapping and terminating 600 volt insulated copper conductors only, and is not acceptable as a method of splicing, tapping or terminating aluminum conductors at any voltage level or copper conductors at voltage level above 600 volts.


3) Where field insulation is required on a 600 volt cable connection, the connection shall be wrapped uniformly with rubber tape to a minimum thickness of twice the cable insulation thickness and than covered by two layers minimum of neoprene tape or scotch #88 or equal plastic tape applied snugly but not stretched.

4) Scotch cast single conductor resin inline and wye splice kits, type 82-A1 thru A3, 82-B1 and 90-B1 or equal, shall be used for 600 volt cable connections. Splice taps and terminations shall be made in accordance with and instructions supplied with joint kit materials.


5) KV shielded cable termination and splicing shall be made in accordance with the drawings. In general for single conductor cabling the following quick termination kits shall be used:a) Termination Kits

3M “Cold Shrink” Quick Term 11 Hi-K silicon rubber termination kits 5630K series outdoor/indoor Class 1 (For outdoor installation s) and 5620K indoor low contamination class 3 for switchgear connections.

5) ...

b. Inline Splice Kits3M “Cold Shrink” 5331 thru 5334 quick splice inline splicing kits.Termination and splicing of medium voltage cable shall be done in accordance with the instructions supplied by the kit manufacturer and in the presence of the company’s representative. For termination and splice kit drain wire grounding details refer to standard drawing STD-60-02.


6) 5KV multi-conductor cables shall be terminated/spliced in accordance with issued drawings and instruction sheets packed in the boxes with the kits purchased for the particular installation. The work shall be performed in the presence of the company’s representative.

7) When forming cables for termination, sharp turns, corners and edges shall be avoided in order to prevent damage to, or weakening of the cable insulation.

8) For 5 kV cable, the cable shield shall be grounded at each splice and termination points.

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Safety is Start from Ourselves

safety for wiring methods

Education

cable type

cable tray system

cable numbers

volt cable connection

overhead cable tray

power limited tray cable

conductors of

minimum cable radius