Technical data

Switchgear compartments
Vacuum circuit breaker cell
The circuit breaker cell is a bolted,
reinforced sheet steel enclosure, with
provisions for a type 38-3AH3 vacuum
circuit breaker. It includes a hinged front
door, inter-compartment and inter-unit
barriers, primary and secondary
disconnects, racking mechanism,
interlocks and CTs, as required by the
application.
Vacuum circuit breaker element
The type 38-3AH3 vacuum circuit breaker
includes a stored-energy operating
mechanism, primary and secondary
disconnects, auxiliary switch, ground
contact, control wiring and interlocks.
Auxiliary cell
An auxiliary cell is similar to a circuit
breaker cell, except without provisions for
a circuit breaker. Space may be used for
VTs, a CPT, drawout primary fuses or
other auxiliary devices. Opening of the
front door does not automatically
disconnect a drawout primary fuse truck
located inside the cell. Instruments and
protective relays can be located on the
front door of an auxiliary cell.
Bus compartment
The bus compartment is a separately
enclosed space for three-phase insulated
main power bus bars, supports and
connections to circuit breaker cells.
Primary termination compartment
The rear area of the unit includes space
for connecting incoming or outgoing
power cables, bus duct connections,
transformer connections or surge
protection devices.
Construction
7
1. Shutter operating linkage
2. Shutters
3. Racking mechanism padlock provisions
4. Primary disconnects (behind shutters)
5. Mechanism operated cell (MOC) switch
(optional)
6. CTs (behind barrier)
7. Secondary disconnect
8. Trip-free padlock provisions
9. CT barrier
10. Racking mechanism
11. Ground bar
12. Rating interlocks
Figure 3: Two views of same circuit breaker cell
interior
1
8
1
2, 4, 6
2, 4, 6
3
5
7
9
9
11
12
12
10