Switchboard large panel assembly panels containing switches,
overcurrent protective devices, buses, and associated
instruments.The step-up transformer used step up
the primary voltage higher secondary voltage.36
Step-upTransformer transformer with fewer turns wire its primary coil than
in its secondary coil. Unlike panelboards, switchboards sometimes
must mounted away from wall allow access rear-
mounted equipment.
Surge Protection Device device designed provide degree protection for
(SPD) electrical equipment from the damaging effects surge.
Danger
.
1:2
120 VAC
I amps
Primary Coil
900 Turns
Secondary Coil
1800 Turns
Vload
= 240 VAC
Iload
= amps
Load
= =
Primary Turns
Secondary Turns
Primary Voltage
Secondary Voltage Primary Current
Secondary Current
Surge increase least ten percent current and voltage that
typically lasts only few microseconds.
Switchgear coordinated design consisting switching and interrupting
devices and associated equipment such control and
protective devices and metering.This
term applies both secondary surge arresters and transient
voltage surge suppressors
