HUW1
Series Intelligent Universal Circuit Breaker
15
Protection set value
5%
– 60% (step length: 1%)
Delay time
0.1 s
– 40 s (step length: 0.1 s)
Protection return set value
5%
– starting value (step:1%)
Delay time
10s
– 200s
No action characteristics
≤0.9 (actual current imbalance rate/set value), no action
Action characteristics
>1.1 (actual current imbalance rate/set value), action
6.4.8
Load monitoring
Load monitoring can be used for pre-alarm and branch load control. The action principle is based on the power or
current monitoring, with two optional modes.
Mode I: The load of two branches can be independently controlled. When the operating parameters exceed the
setting value, the corresponding load monitors the DO delay action (corresponding DO function needs to be set), and
controls the load of two branches to be interrupted to ensure the power supply of the main system.
Mode II:
Generally, it is used to control the load of the same branch. When the operating parameters exceed the
starting value, the "Load Monitoring I" DO delays the action (the action form can be pulse mode or level mode) to
interrupt the branch load.
If the operating parameter value is lower than the return value after the interruption, and
after the delay set time, the "Load Monitoring I" DO returns, and the "Load Monitoring II" DO acts to connect the
interrupted load and restore the power supply of the system.
Unloading I action settings
Current mode 1/2
Setting current I
C1
, I
C2
(0.2
– 1) Ir
Power mode 1/2
Setting power P
C1
, P
C2
200 kW
– 10,000 kW
Unloading I delay settings
Current mode 1/2
Current delay time T
C1
, T
C2
(20%
– 80%) T
r
Power mode 1/2
Power delay time T
C1
, T
C2
10 s
–3,600 s
Unloading II action settings
Current mode 1
Setting current I
C1
(starting value)
(0.2
– 1) I
r
Current mode 2
Setting current I
C2
(return value)
0.2Ir
–I
C
1
Power mode 1
Setting power P
C1
(starting value)
200 kW
–10,000 kW
Power mode 2
Setting power P
C2
(return value)
100 kW
–P
C
1
Unloading II delay settings
Current mode 1
Current delay time T
C1
(20%
– 80%) T
r
Current mode 2
Current delay time T
C2
10 s
–600 s
Power mode 1/2
Power delay time T
C1
, T
C2
10 s
–3,600 s
Protection alarm DO output
Set one DO of the signal unit to "Load Monitoring I" and another to
"Load Monitoring II".
Note: In Mode II, I
c1
≥I
c2
or P
c1
≥P
c2
is required.
6.4.9
Residual current (leakage) protection
It is suitable for the leakage fault caused by equipment insulation damage or human contact with exposed
conductive parts, and the residual current set value 1
Δ
n
is irrelevant to the rated current of the circuit breaker.
The
signal sampling mode is zero sequence sampling, and a rectangular transformer is required. This sampling has high
accuracy and sensitivity, which is suitable for the protection of the small current.
Action current set value
1
Δ
n
0.5A
–30A+OFF
Current tolerance
±10%
Action characteristics
< 0.8l
Δ
n, no action
≥1.01
Δ
n, action
Delay time setting T
Δ
n
(s)
Instantaneous
0.06
0.08
0.17
0.25
0.33
0.42
0.5
0.58
0.67
0.75
0.83
Maximum
breaking time
of fault current
(s)
I
Δ
n
0.04
0.36
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
2l
Δ
n
0.04
0.18
0.25
0.5
0.75
1
1.25
1.5
1.75
2
2.25
2.5
5l
Δ
n,
10l
Δ
n
0.04
0.07
0. 1
0.2
0.3
0. 4
0.5
0.6
0.7
0.8
0.9
1
