Practical Power Plant Engineering. Zark Bedalov

of the region and which can be applied on this project (see Chapter 10). Substations in Zone 2 area must be shielded with overhead shield wires or lightning masts.

Based on the criteria (Chapter 10) and the method of grounding, the equipment shall be protected by the lightning arresters having the following ratings (see Table 2.5):

Table 2.5 System lightning arresters.

	Grid	13 kV Transformer	O/H lines	4.16 kV Switchgear
Voltage (kV)	230	13.8	13.8	4.16
Highest voltage (kV)	245	15	15	5
Grounding	Solid	Resistance	Resistance	Resistance
BIL (kV)	900	95	110	60
MCOVa) (kV)	150	15	15	—
Vr rating (kV)	188	18	18	—
Type (class)	Station	Line	Distr.	Not Req. b)
Discharge current (kA)	10	5	5	—

      ^a) It is the maximum continuous operating voltage r.m.s. (root mean square) voltage that can be continuously applied to the arrester terminals. The selection must consider the voltage regulation that may be applicable to the operating system.

      ^b) The 5 kV switchgear is fed from a transformer which in turn is connected to a 13.8 kV O/H line. The line is protected by lightning arresters on both ends of the line. This protection coverage is considered satisfactory for the 5 kV switchgear.

2.12 Plant Control System

The plant control will be directed from the central control room, having several levels of controls from the production level to the supervisory and management level utilizing DCS and PLCs technologies and appropriate communication links: Ethernet, DeviceNet, ControlBus, as applicable (see Chapter 17 for details).

2.13 Fire Protection

      The plant will be fully protected with fire detection and protection system, including sprinklers and hydrant systems (see Chapter 22 for details).

Reference

      1 1 NEC (National Electric Code) – Ampacity Tables for Cables

Note

      1 1 For a specific reason that is explained in Chapter 7, we will add additional isolation transformers for the lighting systems.