Breaker Switch Unit - Ricoh Aficio 480W Dolphin-C2 Service Manual

28 April 2005

6.12.11 BREAKER SWITCH UNIT

Key to Acronyms
TR
TC
ZCT
R
M
Ig
The breaker switch mechanism consists of a ZCT (Zero Cross Terminal), a sensor
inside the breaker switch unit checks the amplified signals from a detection device.
The main power supply line runs through the ZCT. The ZCT generates a signal if it
detects any fluctuation in the power supply caused by a short circuit.
Normally, the current phase is zero and the breaker does not operate.
When a short circuit occurs:
• The current leakage (Ia + Ib Ic = Ig) flows.
• Voltage is generated at the secondary winding.
• The amplitude of the detection device increases
• The magnetic trip coil operates and opens the breaker circuit to cut the power
supply to the machine.
Transformer
Trip Coil
Zero Cross Terminal
Resistance Test Switch
Load Device
Current Leakage
BOARDS AND BREAKER SWITCH
6-65
B188D907.WMFF