The maintenance work should essentially include:

• inspection of the external condition.
• examination of main/arcing contacts for excessive burning/damage – recondition or renew as required, taking account of manufacturer’s requirements for different contact construction and materials.
• checking/adjusting spring contact force and contact alignment as required.
• removal, examination, and cleaning of the arc chutes – renew if damaged or eroded.
• inspection, adjustment, and lubrication of mechanisms (including shutters where appropriate).
• on withdrawable equipment, examination of primary isolating contacts for damage, burning, corrosion – cleaning and refurbishing.
• on withdrawable equipment, checking and lubrication of circuit-breaker isolating mechanism.
• checking correct function of position indicators and interlocks.
• examining the inside of cable termination chambers and other chambers as appropriate.
• secondary injection testing on circuit-breaker protection system (or, if this is not scheduled, AVAILABLE carry out manual trip-test).
• examination of secondary contacts, wiring and auxiliary switches.