Tenaga Nasional Berhad

5.0 LVCT METERING
LV consumers taking more than 100A per phase shall require current transformers for the metering scheme.
5.1 Location Of Meter Position
i. The Electrical Consultant Engineer / Electrical Contractor is required to arrange for a suitable space for
the metering installation on a panel/cubicle separate from the main switchboard.
ii.
iii.
The position of the meter panel/cubicle shall be determined by the type of LV supply. The final metering
position shall be decided by TNB.
Consumers whose supplies are coming from a substation (load>800A) shall have the meter panel/
cubicle preferably installed inside TNB substation.
iv. The maximum distance of the cable from the CTs to the meter panel allowable is shown in Table 1
below. Prior approval for location of the metering panel shall first be obtained from TNB.
Table 1
CT Burden
VA
Secondary Rated
Current
A
Cross Connection of
Conductor
mm2
Maximum Distance
Allowable
m
7.5
7.5
5
5
2.5
4.0
12.0
20.0
Where meter burden for current circuit is: L.V. = 0.5 VA/ph
5.2 Meter Panel Requirement
i. The meter panel shall be of mild steel or other approved material, and of a thickness not less than
1.5mm.
ii. The meter panel for single feeder metering shall be detachable and as illustrated in Appendix 29,
Drawing No. 6A and 6B.
iii.
iv.
For multi-feeder metering, separate meter panels are to be used for each feeder.
Provisions shall be made for sealing of the meter panel/cubicle.
56 TENAGA
NASIONAL B E R H A D