Switchgear OEM - GE Industrial - #9

1 — Position Indicator

2 — Racking Shaft

3 — Rail

4 — Bearing

5 — Racking Nut

6 — Forward Slot

7 — Cam

8 — Rear Slot

2 3 4

Fig. 7 Negative Interlock

Fig. 8 Key Lock and Padlocks

The negative interlock consists of two notched members in the left-side-track assembly which operate the negative (trip latch) interlock roller on the left side of the breaker. Refer to Fig. 7. On the breaker cubicle one member is stationary and the other is a spring-loaded slide attached to the racking mechanism. A third member, a notched sliding link, provides the key lock functions and is described under KEY LOCKS. See Fig. 8.

To test the function of the negative interlock install a circuit breaker following the instructions given under BREAKER INSTALLATION AND REMOVAL. For this test the con­trol power circuits in the switchgear must be energized.

Place the breaker in the "Disconnect/Test" position and connect the secondary disconnect device by pulling down on the breaker handle and inserting the level arm into the break­er. This will actuate the spring-charging motor and charge the breaker-closing springs. Push the sliding link located on the front of the left track to the rear. Refer to Fig. 8. This will cause the negative interlock roller on the breaker to depress and keep the breaker in the trip free mode. Leave the sliding link in the rear position and attempt to close the breaker using the control switch. Nothing should happen. Now attempt to close the breaker by depressing the manual close button. The closing springs will discharge but the breaker should remain open. Return the sliding link to the forward position.