This section deals with BLPC requirements for the installation of equipment to provide the various electric services which it offers. The requirements for meters and metering equipment are covered in a separate section of this booklet.
» Three Wire Services
» Overhead Services
» Underground Services
THREE WIRE SERVICES
These customers are normally provided with a 115/230 volt, 3 wire, single phase supply from the Company's overhead single phase, low tension distribution mains which is provided from a single polemount transformer.
• 115/230 volt, 3 wire, single phase. Figure 2
In some residential areas, including sections of Bridgetown and Speightstown, the supply available may be 115/200 volt, 3 wire, network, provided from an overhead three phase, low tension distribution system.
• 115/200 volt, 3 wire, network. Figure 1
For customers in large apartment buildings and some residential areas with underground electricity distribution, the supply available may also be 115/200 volt, 3 wire supplied from a three phase padmount transformer or Transformer Room.
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Height and Position of Weatherhead
The weatherhead should be taken up to the eave of the building or to a maximum of 8 metres (25 feet), and the weatherhead and eyebolt should be positioned so that the path of the service drop is not obstructed by the eave of the building. The weatherhead should not be located near to windows or patios. The weatherhead should be securely attached to the building. The minimum height for a weatherhead on a building is as shown in Figure 6 .
Where a service will cross a roadway a minimum of 16 feet (5 metres) clearance is required above the roadway. If this clearance cannot be achieved, it may be necessary to install an extended metal conduit which extends above the roof of the building to the weatherhead. Figure 7 shows a typical extended weatherhead installation. In general the point of attachment shall be so located as to ensure that the minimum clearances given in Figure 7 shall be maintained.
Attachment of Service Drop
There should be a direct path from the pole to the weatherhead without the service cable passing over another person’s property, another building, through trees, or anything that may obstruct the service cable or be considered unsafe. The maximum distance between the pole and the weatherhead is 30 metres (100 feet).
For installations on chattel houses the Company will attach a screw hook to the trimming board which should be securely attached. In the case of a concrete block building it is preferable that the contractor install an eyebolt or J bolt close to the weatherhead and in clear line of sight of the service wires at the pole to accept the service drop. Eyebolts are not provided by the Company and are available at several hardware stores. For a service above 100 amps a larger "oval eye bolt" is required and this can be collected from the Company for installation by the contractor. Figure 8 shows service drop attachments.
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Underground Service Connection from Overhead Network
In cases where an underground service connection to the overhead distribution system is desired, the customer is required to supply, install and maintain the underground service cable in accordance with the Company's standards.
(a) Insulated multicore (PVC or XLPE) armoured cable shall be used for all underground services. Figure 9 shows a typical underground service connection from an overhead network.
(b) Customers using underground services are encouraged to install the meter socket on the external side of the their guard wall as long as they observe the regulations as to the height of the meter position and the regulations of the GEED.
(c) The meter socket in any installation shall be constructed so as to ensure that the incoming line ends cannot be accessed through any unsealed portion of the meter socket.
Residential Underground Distribution
Residential customers in underground developments are normally provided with a 115/230 volt, 3 wire, single phase supply from a turret connected to the Company's underground single phase, low tension distribution mains. On developments designated as underground developments the Company will normally install single phase padmount transformers to meet the capacity requirements of the customers. Single phase padmount transformers are available in the following sizes.
• 15, 25, 37.5, 50, 75 and 100 kVA
Important Note: In cases where the residences are large, and as a consequence the capacity requirements are high, the Company may install three phase padmount transformers to meet the demand. Residential customers in these underground developments will be provided with a 115/200 volt, 3 wire, network supply from a turret connected to the Company's underground low tension distribution mains.
The developer is required to provide the following in accordance with the Company's standards.
1. To supply and install 100 mm (4 inch) conduits for the high voltage cables and 100 mm (4 inch) conduits for the low voltage cables including provision for pulling cables through the conduits. This includes excavation work necessary to install the conduits to the depth required by the Company. For safety reasons the Company requires that the high voltage cables be buried at a minimum depth of 750 mm (2' 6") and be separated by at least 300 mm (1' 0") from other underground facilities belonging to other utilities (e.g. Cable & Wireless (Barbados) Limited).
2. To supply and install the concrete bases for the padmount transformers in locations specified by the Company. In instances where the padmount transformer will be placed near to an area which has vehicular traffic, the developer will be required to provide removable barriers to prevent accidental damage to the transformer (see Figure 15 ).
3. To install an earth mat in conjunction with the concrete base for the padmounted transformer. The earth mat is typically installed at the time of constructing the concrete pad to provide a good electrical earth for the installation (see Figure 10 ).
4. To install concrete manholes and cable ducts in accordance with the Company’s requirements for the high voltage cables, in locations specified by the Company.
5. To install a concrete base and manhole for each low voltage turret, with provision for service conduits from the manhole to each residential customer, as specified by the Company (see Figure 11 A/B ).
6. To supply, install and maintain the underground service conduit and cable from the turret to the meter point. This shall be installed in accordance with the Company's standard for this type of installation. All service cables should be clearly identified and permanently labelled at the time of installation (Figure 12).
7. To supply and install the concrete bases for the streetlight standards and the service conduit from the turret to the base of the standard, including provision for pulling the cables through the conduit. The Company will provide and install the service cable to the streetlight.
Developers should contact the Company in the early stages of planning to discuss their requirements.
Important Note: Special arrangements will have to be made for temporary supply in these areas. Contact the Company as early as possible.
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