Eaton EMR-3MP0 - Start Limits

4.2.6
Start Limits
Because motor starting consumes a considerable amount of thermal energy compared to
its normal load conditions, the number of starts in a given time period must be monitored
and controlled. The EMR-3MP0 has three criteria that contribute to the start limits
monitoring. These are:
• Settings in menu [Protection Para / MStart / Start Control]:
◦ »NOCS« — Number of Cold Starts.
◦
»TBS Fc« in combination with »TBS Timer« — Time between Starts.
◦ »SPH Fc« in combination with »SPH« — Starts per Hour.
• Signals, that can be checked in menu [Operation / Status Display / MStart / Start
Control]:
◦
»ColdStartSeq« — Signal: Motor cold start sequence 󰊏ag.
◦ »NOCSBlocked« — Signal: Motor is prohibited to start due to number of cold
start limits.
◦
»SPHBlockAlarm« — Signal: Motor is prohibited to start due to starts per hour
limits, would come active in the next stop.
◦ »SPHBlocked« — Signal: Motor is prohibited to start due to starts per hour
limits.
◦ »TBSBlocked« — Signal: Motor is prohibited to start due to time between starts
limits.
• Counters, that can be checked in menu [Operation / Measured Values / Motor
Values]:
◦ »ColdStartPermit« — Number of cold starts remaining.
◦
»nSPHBlocks« — Number of start per hour blocks since last reset. Resettable
with [Operation / Reset / History] »Res OperationsCr« or »Res All«.
◦ »nTBSBlocks« — Number of time between start blocks since last reset.
Resettable with [Operation / Reset / History] »Res OperationsCr« or »Res All«.
Most motors can tolerate some number of consecutive cold starts before the time
between starts is enforced. The EMR-3MP0 treats a start as the 󰊎rst in a sequence of cold
starts if the motor had been stopped for at least one hour, or for the time period »TBS
Timer« – if »TBS Fc« = “Active” and »TBS Timer« is set to a duration longer than 1 hour.
Subsequent starts are treated as additional cold starts in the same sequence, only if they
run no more than ten minutes, until the set number of cold starts is reached.
Once the motor is in the cold starting sequence, it ignores the »TBS« and »SPH« limits.
The cold start sequence is terminated if the motor has run for more than ten minutes for
a cold start before it exhausts »NOCS«. All starts after this are subject to time and count
limits imposed by »TBS« and »SPH«.
147www.eaton.comEMR-3MP0
4 Protective Elements
4.2 Motor Starting and Control Module