Circuit-Breaker Failure Protection - ABB REM 610 Technical Reference Manual

REM 610 REM 610
5.1.4.10.
42
Motor Protection Relay
Technical Reference Manual - ANSI Version
The time to the next possible motor start up depends on the countdown rate of the
start-up time counter, 66 COOL /Δt, i.e. the rate at which the register's value
decreases. For instance, if the motor manufacturer allows a maximum of three 60 s'
motor start ups in four hours, 66 should be set to 2 x 60 s + margin = 121 s and 66
COOL/Δt to 60 s/4 h = 15 s/h; see the figure below.
66 value
[s]
150
Start 3 Start 3
120
90
Start 2 Start 2
Restart disable activated 66 (121 s)
60
30
Start 1 Start 1
0
Fig. 5.1.4.9.-1 Cumulative start-up time counter operation
The register's value will decrease during motor start up as well.
If the emergency start has been activated, a motor start up will be
allowed even though the register's value exceeds the set restart disable
value.

Circuit-breaker failure protection

The circuit-breaker failure protection (CBFAIL) detects situations where the the
circuit breaker remains closed although the circuit breaker should have operated.
If a trip signal generated via output PO1 is still active and the current has not been
cut off on expiration of the CBFAIL set operate time, the CBFAIL generates a trip
signal via output PO2.
The CBFAIL is not triggered in case of:
Alarm or a trip of the thermal protection element
*
Alarm or a trip a temperature element
*
Trip of the phase reversal element
*
External trip
*
The CBFAIL can also be selected to be triggered externally by applying a digital
input signal to the relay. In this case, the CBFAIL generates a trip signal via output
PO2 if the current has not been cut off on expiration of the set operate time.
4 h
Next start possible Next start possible
1MRS755537
t
A070087