Woodward MRM4, Manual, Page: 262 / 460

Protective Elements
Protective Elements
MStart - Motor Starting and Control [48,66]
Available elements:
MStart
General – Principle Use
The motor start control logic is the core control and protective function for a motor protection device. The logic
comprises:
•
Motor Operation States;
•
Motor Start Control;
•
Motor Start Blockings;
•
Motor Start / Transition Trips;
•
Motor Cold Warm Detection; and
•
Emergency Override.
Motor Operation States
Motor Operation States
The basic motor operation states can be classified as four states that include:
1. Start cycle;
2. Run cycle;
Page 262 EN MRM4 01/11
START
TRIP
STOP
OFF
BLOCK
RUN
From Other Trip Modules
I > 0,3 *Ib (FLA)
I < 0,3 *Ib (FLA)
TRN Criteria *
Transition on time
only
Transition on
current OR time
Transition on
current only
Transition on
current AND time
*
TRN Criteria