07.05 INSTRUMENT TRANSFORMER ENCLOSURES - GENERAL
CURRENT AND POTENTIAL TRANSFORMER INSTALLATIONS
Current transformers will be furnished by the Company and installed by the Customer (in some areas GPU Energy installs the CT's) when required for either rack mounted service entrances rated over 400 amps or for service entrances rated over 400 amps where current transformer cabinets are utilized. The Customer shall provide the current transformer cabinet or mounting facilities, subject to approval by the Company and the local inspection authority. Current transformer cabinets shall not be used as junction boxes for circuit extensions except where approved by the Company for special cases. The Company must be consulted for all installations requiring current transformers. See figure in Requirements 12.72, 12.73, 12.76, 12.77 & 12.78 for specifications of the current transformer cabinet and Requirement 13.40 for catalog numbers which are approved for use in the Company's service territory. Line and load side must be identified by the Customer in all current transformer cabinets.When it is impractical to install the current transformer cabinet as shown in figure in Requirements 12.76, 12.77 & 12.78 , the Company should be consulted for approval of alternate arrangements. When meters are installed at remote locations, the meters and current transformer cabinet must be interconnected with a 1 1/4 inch minimum rigid conduit not to exceed 15 feet in length.
For installations where the voltage is greater than 480 volts, potential transformers will by supplied by GPU Energy.
All current transformer cabinets will be inspected by the Company and secured with special locking devices to ensure the integrity of the metering installation. If an electrician needs to gain access to a CT rated metering installation for the purpose of performing electrical work, the Company must be contacted to arrange for the opening and relocking of the CT cabinet.
A line side tap shall not be permitted in a current transformer cabinet for the purpose of adding any single-phase or three-phase self contained meters.
All single-phase and three-phase metering installations, up to and including 800 amps, will be located outdoors. This requirement applies to the current transformers, as well as the meters. An exception to this requirement must be approved by the Company.
SERVICES UNDER 600 VOLTS
The Customer shall provide, install, own and maintain the following:
Instrument transformer enclosure shall be approved by the GPU Energy Meter Department (see Requirement 13.40 ). The maximum length of the conduit between the enclosure and the meter socket shall be fifteen (15) feet. In addition, a clear space of at least four (4) feet in front of and one (1) foot on each side of the enclosure is required.
1-1/4 inch minimum rigid conduit, including required bushings and fittings shall be installed between the instrument transformer enclosure and the meter mounting device shall be sized as follows:
The enclosure and meter mounting device shall be grounded using #4 AWG copper wire connected to the service equipment ground. Enclosures must have provisions for grounding to accommodate #4 AWG copper wire.
Enclosures shall not be used as junction boxes or wiring troughs. Conductors shall enter and leave the enclosure as one circuit. When more than one conduit is used to enter and leave the enclosure, each conduit shall contain conductors from each of the three phases in addition to the neutral.
Whenever the service exceeds 2400 amperes, GPU Energy requires that the Customer shall provide a switchgear enclosure for metering.
End of Specification:
Created: |
05/16/2000 | |
Last Revised: |
05/16/2000 |
