ABB REQ650 Product Manual - page 13
An alarm level gives early warning to allow operators to take
action well before the line is tripped.
Estimated time to trip before operation, and estimated time to
reclose after operation are presented.
Breaker failure protection CCRBRF
M11550-6 v16
Breaker failure protection (CCRBRF) ensures a fast backup
tripping of the surrounding breakers in case the own breaker
fails to open. CCRBRF can be current-based, contact-based
or an adaptive combination of these two conditions.
A current check with extremely short reset time is used as
check criterion to achieve high security against inadvertent
operation.
Contact check criteria can be used where the fault current
through the breaker is small.
CCRBRF can be single- or three-phase initiated to allow use
with single phase tripping applications. For the three-phase
version of CCRBRF the current criteria can be set to operate
only if two out of four for example, two phases or one phase
plus the residual current start. This gives a higher security to
the back-up trip command.
CCRBRF function can be programmed to give a single- or
three-phase re-trip of its own breaker to avoid unnecessary
tripping of surrounding breakers at an incorrect initiation due
to mistakes during testing.
Stub protection STBPTOC
M12902-3 v9
The primary line distance protection will thus not be able to
operate and must be blocked.
The stub protection STBPTOC covers the zone between the
current transformers and the open disconnector. The three-
phase instantaneous overcurrent function is released from a
normally open, NO (b) auxiliary contact on the line
disconnector.
Broken conductor check BRCPTOC
SEMOD171446-5 v2
The main purpose of the function Broken conductor check
(BRCPTOC) is the detection of broken conductors on
protected power lines and cables (series faults). Detection
can be used to give alarm only or trip the line breaker.
4. Voltage protection
Two step undervoltage protection UV2PTUV
M13789-3 v11
Undervoltages can occur in the power system during faults or
abnormal conditions. Two step undervoltage protection
(UV2PTUV) function can be used to open circuit breakers to
prepare for system restoration at power outages or as long-
time delayed back-up to primary protection.
UV2PTUV has a high reset ratio to allow settings close to
system service voltage.
Two step overvoltage protection OV2PTOV
M13798-3 v14
Overvoltages may occur in the power system during abnormal
conditions such as sudden power loss, tap changer
regulating failures, and open line ends on long lines.
OV2PTOV has a high reset ratio to allow settings close to
system service voltage.
Two step residual overvoltage protection ROV2PTOV
M13808-3 v10
Residual voltages may occur in the power system during
earth faults.
Two step residual overvoltage protection ROV2PTOV function
calculates the residual voltage from the three-phase voltage
input transformers or measures it from a single voltage input
transformer fed from an open delta or neutral point voltage
transformer.
Two step residual overvoltage protection ROV2PTOV function
calculates the residual voltage from the two-phase voltage
input transformers or measures it from a single voltage input
transformer fed from a neutral point voltage transformer.
ROV2PTOV has two voltage steps, each with inverse or
definite time delay.
ROV2PTOV has two voltage steps, each with definite time
delay.
Loss of voltage check LOVPTUV
SEMOD171457-5 v7
Loss of voltage check LOVPTUV is suitable for use in
networks with an automatic system restoration function.
LOVPTUV issues a three-pole trip command to the circuit
breaker, if all three phase voltages fall below the set value for
a time longer than the set time and the circuit breaker
remains closed.
The operation of LOVPTUV is supervised by the fuse failure
supervision FUFSPVC.
5. Multipurpose protection
General current and voltage protection CVGAPC
M13083-11 v9
The General current and voltage protection (CVGAPC) can be
utilized as a negative sequence current protection detecting
unsymmetrical conditions such as open phase or
unsymmetrical faults.
6. Secondary system supervision
Current circuit supervision CCSSPVC
M12444-3 v10
Open or short circuited current transformer cores can cause
unwanted operation of many protection functions such as
differential, earth-fault current and negative-sequence current
functions.
Current circuit supervision (CCSSPVC) compares the residual
current from a three phase set of current transformer cores
1MRK 505 358-BEN B
Breaker protection REQ650 2.1 IEC
Product version: 2.1
ABB
13