Functions; Protection - Mitsubishi Electric CBV2-A01D1 Instruction Manual

4

Functions

4.1 Protection

4.1.1. Undervoltage elements
Fig. 4.1 "Undervoltage element internal function block diagram" shows operation of the undervoltage
elements.
Undervoltage element compares input voltages of voltage circuit with the operation setting. If an input
voltage is less than the specified operation level, the element outputs an operation signal when the timer
expires.
AB-phase processing
Undervoltage element
V
AB
Voltage comparison
BC-phase processing
V
BC
CA-phase processing
V
CA
Figure 4.1 Undervoltage element internal function diagram
4.1.2. Overvoltage elements
Fig. 4.2 "Overvoltage element internal function block diagram" shows operation of the overvoltage
elements.
Overvoltage element compares input voltages of voltage circuit with the operation setting. If an input
voltage is larger than the specified operation level, the element outputs an operation signal when the timer
expires.
AB-phase processing
Overvoltage element
V
AB
Voltage comparison
BC-phase processing
V
BC
CA-phase processing
V
CA
Undervoltage element detected
(Operation indicator LED blinking)
(trip/reset)
Same as processing in AB-phase
Same as processing in AB-phase
Overvoltage element detected
(Operation indicator LED blinking)
(trip/reset)
Same as processing in AB-phase
Same as processing in AB-phase
Figure 4.2 Overvoltage element internal function diagram
Undervoltage element detected
(Operation indicator LED lit)
Timer
Overvoltage element detected
(Operation indicator LED lit)
Timer
10
Operation signal
(Undervoltage element)
Operation signal
(Overvoltage element)
PCKN-OIL738