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
0
120
90
60
30
[s]
150
4 h
t
Start 1
Start 2
Start 3
Next start possible
Restart disable activated 66
(121 s)
Start 1
Start 2
Start 3
Next start possible
A070087
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.
5.1.4.10. 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.
42
REM 610REM 610
Motor Protection Relay
Technical Reference Manual - ANSI Version
1MRS755537
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