8BK86 (KYN18-12) metal-clad Withdrawable switchgear is suitable for 3-phase AC 50Hz, 7.2~12kV single busbar and single busbar section system. Apply to distribute electricity power and implement system control, protection and supervision monitoring. The switchgear complies with the standards IEC298, GB3906, DL404.
Functional Features
A. Safety for use
1. All switching operations take place with high-voltage compartment doors closed.
2 Electrical switch positon indication on panel fornt for circuit-breaker, earthing switch and truck position.
3. Logical interlocks prevent maloperation.
4. Positively driven shutters protect against accidental contact with live parts.
5. Standard degree of protection IP4X against electric shock and ingress of solid foreign bodies.

B. Interlock
Operating levers can only be inserted when the interlocking conditions are fulfilled. In this way, undue stress on the interlock mechanisms is avoided. The following operations can only take place when the stated interlock conditions are fulfilled:
1. Move the withdrawable part from the test position to the service position: High-voltage compartment door closed/ VCB or VC in the OPEN position / (Make-proof) earthing switch in the OPEN position.
2. Move the withdrawable part from the service position to the test position: VCB or VC in the OPEN position.
3. Operate the VCB or VC: Withdrawable part have been locked in the test position or the service position.
4. Operate the (make-proof) earthing switch: Withdrawable part have been locked in the test position. Cable compartment door closed.
5. Opening the high-voltage compartment door: Withdrawble part have been locked in the test position.