Current Transformers
The torroidal current transformers shown installed in a unit in
Figure 32
are the most commonly used type in metal-clad
switchgear equipment. The circuit breaker primary studs pass
through the transformers when in the CONNECT position. Types
MD or MDD current transformers are of the torroidal type
mounted in the circuit breaker compartment behind the shutter
barrier. Up to two standard or one high accuracy current trans-
formers may be mounted around each primary insulator tube.
Figure 32.
Type MD CT’s Installed on Upper and Lower
Disconnects (CT Barrier Removed for Photo)
A zero sequence torroidal current transformer can be furnished
for ground sensing circuits. This transformer is mounted in the
primary cable area at a convenient height for receiving pur-
chaser’s cables. Zero sequence current transformers may
require that conduits for multiple bottom entrance cables be
recessed.
Instrument Transformers
36
1564-95
