Woodward MRM4, Manual, Page: 273 / 460

Protective Elements
If enabled, an emergency override can be executed by pushing the » Emrg Override« Softkey at the front panel.
In any case, an emergency override can be performed by a remote contact connected to any one of the digital
inputs programmed as » EMG OVR« , or via front panel under [Operations\Reset\EMGOVR] menu. The as-
shipped setting is disabled.
Emergency override allows a panic restart of a tripped motor without completely disabling protection. When the
override request is received, the thermal-model accumulator bucket is drained to its initial level of 40°C (104°F).
Cold starts are fully restored.
The motor protection is now in the state it would be in if the motor had been standing for a long time prior to the
moment of the override. This allows an immediate restart of the motor. The override can also delay an
impending thermal trip of a running motor. The emergency override action is counted in the history record, and
noted with its time tag in the logbook record.
The emergency override function clears and restarts all protective
functions of the protective device. Using this function can damage the
motor. Use it only for true emergencies, when it is known what caused the
trip. Override permits the risk of motor damage to avoid an even more
dangerous process situation caused by the tripping of the motor.
Global Protection Parameters of the Motor Start Module
Parameter Description Setting range Default Menu path
Reversing Reversing or non
reversing starter. This
option will affect the
sequence current
calculations. inactive,
active
inactive [Field Para
/Motor]
Ib Full load current
(amperes). Set to
maximum stator
continuous RMS current
primary (actual motor
winding) amperes in each
phase. Use motor
nameplate or
manufacturers data.
Note that the ratio Ib/CT
prim must lie between
0.25 and 1.5 in order to
have reliable motor
protection. 10 - 6000A 10A [Field Para
/Motor]
LRC Set to the locked-rotor
current (the current the
motor draws when
stalled), in times of Ib.
Use motor nameplate or
manufacturers data. 3.00 - 12.00Ib 3.00Ib [Field Para
/Motor]
EN MRM4 01/11 Page 273