Installation checks and functional tests
Heavy weight.
Can result in death, serious injury or property damage.
Do not transport a circuit breaker using a lift truck with the lift truck in the raised position.
Figure 2: Type 38-3AH3 vacuum circuit breaker racking
5.Move the circuit-breaker release latch (on the floor of the cell near the right side of the circuit breaker) to the left and pull the circuit breaker out from the DISCONNECT position. The circuit breaker can now be removed from the cubicle and rolled out onto the two extension rails.
6.Remove the circuit breaker from the two extension rails using the approved Siemens circuit-breaker lifting device or Siemens lifting sling and a suitable crane.
7.Lift the two extension rails and withdraw them from the switchgear.
8.Close the circuit-breaker compartment door and secure all latches.
Type 38-3AH3 vacuum circuit breakers weigh between 800 and 1,000 lbs (364- 455 kg) depending upon ratings. The circuit breaker can be moved using a properly rated crane and lift sling. A lift sling can be attached to the circuit breaker, and then used to hoist the circuit breaker vertically clear of the extension rails. When clear, remove the rails and lower the circuit breaker to the floor.
Racking crank engagement procedure
A crank for racking the circuit breaker is provided as a standard accessory. Racking a circuit breaker can be accomplished with the drawout-compartment-front door open or through a small opening (or window) in the front door, with the door closed. Racking a rollout-fuse truck is accomplished with the compartment-front door open.
The racking crank consists of an offset handle with a custom socket assembly welded to the end. The socket end of the crank is designed to engage the shoulder of the racking-mechanism shaft and remain engaged during racking with spring plungers. The plungers operate in a manner similar to the retainers of an ordinary mechanic’s socket wrench.
The portion of the racking-mechanism shaft visible is cylindrical, and the shoulder of the racking-mechanism shaft is hidden by a shroud until the engagement procedure starts. The square socket-end of the crank will only engage the shoulder of the shaft if it is aligned properly.
Figure 3: Use of extension rails for voltage transformer (VT) fuse- rollout truck or circuit breaker not at floor level (VT fuse-rollout truck in upper cell shown. Procedure for circuit breaker in lower cell but not at floor level is similar.)
