Commissioning And Maintenance Of The Fault Clearing System; Installation And Commissioning - ABB Relion REG650 Commissioning Manual

Generator protection

Table of Contents

1MRK 502 035-UEN A

Section 8

8.1

Commissioning and maintenance of the fault clearing

system

About this chapter

This chapter discusses maintenance tests and other periodic maintenance measures.

8.1.1

Installation and commissioning

The protection IED is in an on-guard situation where the IED can be inactive for several years

and then suddenly be required to operate within fractions of a second. This means that

maintenance testing with certain time intervals should be performed to detect failures of the

protection IED or the surrounding circuits. This is a complement to the advanced self

supervision in the modern protection IED.

IEDs are not expected to deteriorate with usage but extreme conditions, such as mechanical

shocks, AC or DC transients, high ambient temperatures, and high air humidity always have a

certain likelihood of causing damages.

Delivered equipment undergoes extensive testing and quality control in the ABB

manufacturing program. All types of IEDs and their integral components have been subject to

extensive laboratory testing during the development and design work. Prior to series

production of a specific IED, it is type tested according to national and international

standards. Each individual IED in normal production is individually tested and calibrated before

delivery.

Protection IEDs installed in an apparatus cubicle shall be checked in various ways before

delivery. Insulation test (to check for bad wiring) and complete testing of all equipment with

injection of currents and voltages is performed.

During the design of the station, certain steps shall be taken to limit the risk of failures, for

example, all IED coils are connected to negative potential to earth to prevent contact corrosion

due to electrolyte.

Certain circuits are continuously supervised to improve their availability. Examples of such

supervisions are:

•

Trip circuit supervision

•

Protection DC supply supervision

•

DC system earth fault supervision

•

Busbar protection CT-circuit supervision

Protection IEDs shall be encapsulated according to environment requirements. In tropical

climates, cubicles are provided with glass-door and ventilation louvres. Heaters for anti-

condensation, often thermostatically controlled, are provided. Cubicle power-loss is limited

not to exceed protection IED temperature limits, which is 55°C according to the IEC standard.

Generator protection REG650

Commissioning manual

Commissioning and maintenance of

the fault clearing system