ABB RELION 620 Series Technical Manual page 771

1MRS757644 F
620 series
Technical Manual
GUID-6E9B7247-9009-4302-A79B-B326009ECC7A V2 EN
Figure 392: Typical motor-starting and capability curves
Setting of Cumulative time Lim
Cumulative time Lim is calculated by
t ( n ) 1 t margin
∑
= − × +
si
GUID-0214B677-48D0-4DD4-BD1E-67BA9FD3C345 V1 EN
n specified maximum allowed number of motor start-ups
t start-up time of the motor (in seconds)
margin safety margin (~10...20 percent)
Setting of Counter Red rate
Counter Red rate is calculated by
t
t
∑
∆ =
s
t
reset
GUID-E7C44256-0F67-4D70-9B54-1C5042A151AF V1 EN
t specified start time of the motor in seconds
t duration during which the maximum number of motor start-ups stated by the manufacturer can be
reset
made; time in hours
Section 4
Protection functions
(Equation 144)
(Equation 145)
765