HUW1
Series Intelligent Universal Circuit Breaker
17
6.4.13
Undervoltage protection
The intelligent controller measures the true RMS of the primary circuit voltage. When all three phase-to-phase
voltages (line voltages) are less than the set value, that is, when the maximum value of three line voltages is less than
the set value of the undervoltage protection, the undervoltage protection acts; when the maximum value of three line
voltages is greater than the return value, the alarm action returns.
Action threshold (V)
100
–return threshold (step length: 1)
Action delay time (s)
0.2
–60 (step length: 0.1)
Return threshold (V)
Action threshold
– 1,200 (step length: 1)
This set value is only available when the execution mode is
"Alarm", and the return value must be greater than or equal to
the starting value.
Action delay time (s)
0.2
–60 (step length: 0.1)
Action or alarm
characteristics
(delay tolerance±10%)
Umax/action threshold
≤0.9
Fixed time action
Umax/action threshold >1.1
No action
Undervoltage alarm return
characteristics
(delay tolerance±10%)
Umin/action threshold >1.1
Fixed time return
Umin/action threshold
≤0.9
No return
Alarm contact output
When the execution mode is
“Alarm”, the "Undervoltage Alarm" contact output can be added
6.4.14
Demand current protection
Calculate the demand value of the true RMS of each phase current in a sliding time window, and perform
protection action when the demand value exceeds the limit. When the execution mode is
“
Alarm
”
, its action principle
is the same as that of grounding alarm. The setting of the sliding time window is in the menu item "Meter Settings" (the
parameters are set in the same way for phases A, B, C and N).
Protection starting set value (A)
(0.2
–1.0) In
Action delay time set value (s)
15
–1,500
Protection action return set value (A)
0.2 In
–starting set value
This set value is only available when the execution mode is "Alarm".
Protection return delay time (s)
15
–3,000 s
Demand current action
characteristics
(delay tolerance±10%)
I/Starting set value
≤0.9
No action
I/Starting set value>1.1
Fixed time action
Demand current return
characteristics
(delay tolerance±10%)
I/Return set value>1.1
No return
I/Return set value
≤0.9
Fixed time return
Protection execution mode
Alarm/trip/shutdown
6.4.15
Underfrequency & Overfrequency protection
The intelligent controller detects the frequency of the system voltage, and can perform protection if the frequency
is too high or too low. The action principle and characteristics of overfrequency and underfrequency protection are the
same as those of overvoltage and undervoltage protection.
Setting range of
different
parameters
Action threshold
Underfrequency
45
– return value (step length: 0.5 Hz)
Overfrequency
Return value
– 65 Hz (step length: 0.5 Hz)
Action delay time
0.2
–5.0 s (step length: 0.1 s)
Return threshold
Underfrequency
Starting value
– 65 Hz
This set value is only available when the
execution mode is "Alarm"
Overfrequency
45 Hz
– starting value
Return delay time
0.2
– 36.0 s (step length: 0.1 s)
Alarm contact
output
When the execution mode is
“Alarm”, the "Underfrequency Alarm" and “Overfrequency Alarm” contact output can be
added
Protection
execution mode
Alarm/trip/shutdown