Annex 7: Interconnection Facility

A.1 Responsibility and Cost of Installation of Interconnection Facilities

1. CEB shall be responsible for the construction, installation and commissioning of the 22kV interconnection line forming part of the CEB Interconnection Facilities. CEB shall own and be responsible for the operation, maintenance and repair of the CEB Interconnection Facilities.
2. The Applicant shall be responsible for the acquisition of the right of way for CEB with regard to the interconnection 22kV line with CEB 22 kV existing network.
3. The Applicant shall be responsible for the construction, installation, testing and commissioning of the complete 22kV switchboard as per Annex 6 (section 7.6 of this Grid Code), i.e. the CEB as well as the MSDG side. CEB will take ownership of its side after the guarantee period.
4. The Applicant shall bear the cost of the procurement, installation, testing and commissioning of both CEB and MSDG's Interconnection Facilities.
5. The Applicant shall be responsible for all civil works inclusive of cable trench, draw-pits, laying of PVC pipes and construction of switchgear room as per CEB specifications. All Civil Works shall be approved by the CEB prior to implementation.
6. The Applicant shall own and be responsible for the operation, maintenance and repair of MSDG's Interconnection Facilities.

A.2 CEB Interconnection Facilities

A2.1 Scope of CEB Interconnection Facilities

The CEB Interconnection Facilities shall be as per the current Technical Specifications for HT Metering, as reproduced hereunder.

Note: The latest version of the Technical Specifications for HT Metering shall be applicable to the MSDG at the time of implementation.

PART I: HT SWITCHGEAR

Schedule A1 - General

1. Network

2. Cubicles

Arrangement of Cubicles under CEB's responsibility

The cubicles under Central Electricity Board's responsibility and those under client's responsibility shall form one single switchboard. However, Central Electricity Board's liability shall stop at the point of supply found at the outgoing terminals of the circuit breaker in Cubicle No. 4.

The cubicles' arrangement shall be from left to right as follows:

Cubicle No. 1 (Incoming No. 1)

22 kV load break switches for the control of first incoming feeder (see item 1).

Cubicle No. 2 (Incoming No. 2)

22 kV load break switches for the control of second incoming feeder (see item 1).

Cubicle No. 3

Voltage Transformer (V.T) Cubicle (see item 2).

Cubicle No. 4

CEB Circuit Breaker cubicle with double isolation (see item 3).

Degree of Protection

IP 3X.

Safety equipment for switching operations

The client should provide the following safety equipment which shall be always readily available in the switchgear room:

On Client side:

1. 22 kV insulating mat.
2. One pair of 22 kV insulating gloves.
3. Appropriate Line tester with both visual and audible features.
4. Rescue rod

The client to ensure that the above items are maintained on a regular basis.

ON CEB side:

1. 22kV insulating mat is required.

The Client shall ensure that all the fire extinguishers shall be in good working condition. For fire extinguisher on CEB side, the Client shall inform CEB with one week notice for maintenance/inspection of fire extinguisher.

Spares

The client shall provide the following spares for the cubicles under Central Electricity Board's responsibility:

1. 1 set Voltage Transformer as specified in item 2.
2. 1 set Current Transformer as specified in item 3.
3. 1 set HRC fuses as specified in item 2.
4. 1 charging motor for item 1
5. 1 charging motor for item 3.

Standards

The switchboard shall conform to the following standards or the relevant parts thereof:

Note: All specifications shall be according to the latest edition of the standards mentioned above.

Protection Relays

Appropriate numerical protection relays having technical specifications detailed in Schedule A2 shall be provided on the CEB circuit breaker cubicle.

Communication Systems

In line with the implementation of Distribution Management System (DMS), the 22kV switchgear shall make provision for transfer of real-time operating data and protection and control signals via a communication system to the CEB SCADA. The communication system comprising of the Remote Terminal Unit (RTU), Relay Panel/ Transducers and the communication channel shall be installed and tested by the CEB.

However, the Client shall provide the connection link of the signals from the switchgear panels to a dedicated terminal block fitted in a wall-mounted control cubicle with hinged door placed inside the CEB side of the room. The required signals together with a simplified block diagram of the communication system are provided in schedule A3.

It is to be noted that the maximum load required for the communication equipment is around 500W.

Safety Procedures

Safety Procedures regarding the operation of HT Switchgear are described in Schedule A4.

General Notes:

1. The bus riser cubicle and transformer protection cubicles shall be specified by client.
2. The current and voltage transformers (including the spares) have to be sent to CEB Meter Laboratory for necessary tests before commissioning.
3. The client should also provide a 2-pole circuit breaker on the secured AC auxiliary supply for the spring charging mechanism inside the LV upper compartment of the CEB circuit breaker module.
4. The operation of the equipment under Central Electricity Board's responsibility shall require secured AC auxiliary source of supply also protected by surge and lightning devices. An online uninterruptible power supply (UPS) is required and it shall have adequate capacity to ensure that the protection, measurement, control and communication systems operate without interruption for a minimum duration of at least 3 hours after loss of CEB power supply. The Client shall submit the calculations in the determination of the sizing of the UPS. In the event of loss of the secured auxiliary supply, all the Client's 22kV circuit breakers shall be tripped until remedial actions are taken. The UPS system shall be installed on the Client side and be maintained accordingly by the Client. The UPS shall be equipped with a bypass switch/system that will allow continuous operation during maintenance on the UPS.
5. For clients with standby generator, an electrical & mechanical interlock (break before make) be provided in such a way that the generator supply does not feed at any time the CEB's network.

Guaranteed Particulars

The Client shall also supply all relevant data where applicable by filling in the Schedule of Guaranteed Particulars - Schedule B1.