5-202
M60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
GROUPED ELEMENTS
CHAPTER 5: SETTINGS
5
Motor cooling is calculated as follows.
Eq. 5-14
Eq. 5-15
where
TCU = thermal capacity used
TCU
start
= TCU value caused by overload condition
TCU
end
= TCU value dictated by the hot/cold curve ratio when the motor is running. This value is 0 when the motor is
stopped)
t = time in minutes
τ
= cool time constant (running or stopped per current motor status and corresponding
COOL TIME CONSTANT RUNNING
and
COOL TIME CONSTANT STOPPED
settings)
I
eq
= equivalent motor heating current
overload_pickup = overload pickup setpoint as a multiple of FLA
hot / cold = hot/cold curve ratio
Summary of Contents for M60
Page 9: ...TABLE OF CONTENTS M60 MOTOR PROTECTION SYSTEM INSTRUCTION MANUAL ix INDEX ...
Page 10: ...x M60 MOTOR PROTECTION SYSTEM INSTRUCTION MANUAL TABLE OF CONTENTS ...
Page 552: ...5 344 M60 MOTOR PROTECTION SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 5 SETTINGS 5 ...
Page 660: ...iv M60 MOTOR PROTECTION SYSTEM INSTRUCTION MANUAL ABBREVIATIONS ...