Can I control the number of automatic restart attempts on my LTMR after a voltage dip condition has been detected?

Issue:
Need to limit the number of automatic restart attempts after a voltage dip condition occurs.

Product line:
LTMR Tesys T

Environment:
All models with LTM-E expansion module attached.

Cause:
Information is unclear in the current literature.

Resolution:
It is not possible to limit the number of restart attempts in the LTMR to a specific number of attempts.  The function can be disabled, set to "load shedding" mode, or set to automatic restart.  The function requires an LTM-E expansion module, it is not present in the LTMR without the expansion module attached.

There are three registers in the LTMR that track the number of restart attempts, depending on what type of restart occurred:

Auto Restart Immediate count: When a voltage dip occurs but the voltage returns to normal quickly (within the time set by the parameter " Auto restart immediate timeout" the LTMR will perform an immediate restart and increment the "Auto restart immediate count" by one.

Auto Restart Delayed count:  When a voltage dip occurs and the voltage remains low for an extended time (longer than the "Auto Restart Immediate Timeout" parameter) the LTMR will wait to attempt to restart the motor.  The amount of time the LTMR waits before attempting restart is set via the "Auto restart delayed timeout" parameter.  Once a delayed restart occurs, the LTMR increments the "Auto Restart Delayed Count" by one.

Auto Restart Manual Count:  If a voltage dip occurs and the voltage remains low for a time greater than "Voltage Dip Restart timeout" then an auto restart will not occur.  It will be necessary to cycle the run command to the LTMR in order to restart.   The LTMR records the number of times this occurs under the parameter "Auto Restart Manual Count".

Publicado para: Schneider Electric España