HUW1
Series Intelligent Universal Circuit Breaker
18
6.4.16
Reverse power protection
The sum of three-phase active power is taken for the inverse power protection. When the direction of power flow
is opposite to that of the user
’
s setting power and greater than the set value, the protection starts.
The direction of
power and the incoming direction of power supply are set in the "Meter Settings" menu, which must be consistent with
the actual application.
Its action principle is the same as overvoltage protection.
Protection starting set value
5
–500 kW
Protection action delay time set
value
0.2
–20 s
Protection action return set value
5 kW
– starting set value
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.
Protection return delay time
1.0
–360 s
Protection alarm DO output
Set one DO of the signal unit to "Power Failure".
Protection execution mode
Alarm/trip/shutdown
6.4.17
MCR and HSISC protection
MCR and HSISC are instantaneous protection for the adjustment of the circuit breaker itself. When the
out-of-limit fault current generates, the intelligent controller will issue a trip instruction within 10 ms. Among them,
MCR protects the switch-on ability of the circuit breaker to prevent the switch from being damaged due to the
switch-on current exceeding the switch-on limit ability, and the protection works at the moment of opening and closing
of the circuit breaker (within 100 ms). HSISC protects the maximum carrying capacity of the circuit breaker to prevent
the switch from carrying the current exceeding the maximum breaking capacity, which will take effect after closing for
100 ms.
MCR, HSISC action current set value (kA)
30
–100
No action characteristics
< 0.80I/I
i
No action
Action characteristics
> 1.0I/I
i
Action
Action delay
< 20ms
Note: This group of set values is generally set according to the breaking capacity of the circuit breaker when the
circuit breaker leaves the factory, and is not adjustable by the end user.
Factory default MCR: HUW1-1000/20 kA; HUW1-2000 above /50 kA.
HSISC: HUW1-1000/30kA; HUW1-2000/50kA; HUW1-3200/65kA; HUW1-4000/80kA; HUW1-6300/100kA.
6.4.18
Self-diagnosis
The intelligent controller can diagnose its own faults, including
ultra-high ambient temperature, error of E
2
PROM
data, error of A/D sampling, and circuit breaker failing to act.
6.4.19
Contact wear indication
The intelligent controller can display the current contact wear on the screen. When the intelligent controller
leaves the factory, the display value is 100%, which means that the contact is not worn. When the display value drops
to 60%, an alarm signal will be sent to remind the user to take maintenance measures timely. After the contact is
replaced, it can be restored to the initial wear value through setup.
6.4.20
Test & Lock
There are three test modes for test tripping, namely three-section protection, grounding/leakage fault and
mechanism action time.
Three-section protection test: Input the fault current to simulate the protection of the controller when the overload,
short circuit or transient fault occurs.
Grounding/leakage fault test: Input the grounding/leakage fault current to simulate the protection of the controller
when the grounding/leakage fault occurs.
Mechanism action time test: Force the magnetic flux converter to act to test the inherent mechanical time of
circuit breaker tripping.
6.4.21
Zone selective interlock
In the same power circuit, two or more circuit breakers with superior-subordinate relationship can realize zone
selective interlock, which includes short-circuit interlock and grounding interlock. There are two possibilities for this
interlock according to the location of the fault.
1.
When the location of the short circuit or ground fault is at the outgoing side of the subordinate circuit breaker
(2#
–
4# circuit breaker), such as location
②
, the subordinate circuit breaker trips instantaneously and sends a
regional interlock signal to the superior circuit breaker;
the superior circuit breaker (1# circuit breaker) receives the
regional interlock trip signal and delays according to the short circuit or grounding protection settings. If the fault
current is eliminated during the delay of the superior circuit breaker, the protection will return and the superior circuit
breaker will not act; if the fault current of the subordinate circuit breaker is still not eliminated after tripping, the
superior circuit breaker will act according to the short-circuit or grounding protection setting to cut off the fault line.
