Compartment
locking tab
Secondary
disconnect
Removable, reusable
boots
Primary
contacts
Drawout truck and
racking system
T EC H N I C A L A N D A P P L I C AT I O N G U I D E
11
PT/CPT/Draw-out fuse compartments
Similar to breaker compartments, potential trans-
former, control power transformer and draw-out fuse
compartments are inserted via an automatic latching
insertion mechanism which allows for closed door in-
sertion of auxiliary equipment. The cell interface uses
the same components as the circuit breaker module
and is compatible with ABB’s remote racking device,
the SmartRack. Secondary contacts engage/disen-
gage automatically and interlocks ensure proper op-
eration where applicable.
All primary auxiliary compartments, including poten-
tial transformers, control power transformers and
draw-out fuse compartments, use arc-quenching Del-
rin® technology for primary contact assemblies (Del-
rin is a registered trademark of DuPont). A Delrin®
tipped conductor probe is inserted into a Delrin® re-
ceptacle with recessed contacts. During load break,
localized heating of the Delrin® material due to arcing
causes the material to release an inert gas which fills
the small isolating gap to contain the arc and extin-
guish it safely.
The PT drawout units can be withdrawn beyond the
front of the frame via rails, which allow easy access
to the fuses for inspection or replacement.
Control Power Transformer (CPT) and Draw-out
fuses
CPT modules provide convenient mounting and op-
eration of single-phase control power transformers
in ratings up to 15kVA, minimizing the possibility of
inadvertent interruption of control power for AC
operated switchgear.
Fuse modules accommodate up to three primary
fuses for use with fixed-mount control power
transformers. Fuse modules are provided with sta-
tionary control power transformers in ratings up to
75 kVA three-phase or 50 kVA single phase. Fixed
mounted CPTs can be mounted in the rear lower ca-
ble compartment or at a remote location.
—
Compartment types
Auxiliary modules
—
01 Delrin primary
probe and recessed
contact assembly
—
02 PT drawout assembly
with three voltage
transformers - the
fuses can be removed
without removing the
PT truck from the rails
—
01
—
02
