EarthLinked SCWD-024-1C, Quick Start Instructions

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SCWD-QS (12/16) Page 19
5) SureStart
Features
SureStart is an optional factory installed soft starter that reduces light flicker caused at start-up by
scroll compressor motors. This control has the following features:

60 to 70% reduction in direct in-rush current

Under voltage protection

Motor reversal protection

Self-adjusts for optimal start performance

50/60 Hz compatible

ETL, CE, EMC and RoHs compliant

Tolerant to “dirty power” conditions

Fault LED

Internal current limiting

Run capacitor monitoring
SureStart is factory wired for the appropriate power supply.
Operation
When the system control calls for compression operation, the compressor contactor will energize. If
the supply voltage is less than “minimum start-up voltage”, a 50 second delay is initiated. At the end
of the delay, another attempt will be made to start the compressor unless the supply voltage remains
unchanged. See Figure 11 for the SureStart Mode of Operation.
SureStart uses an optimated starting process that learns the starting characteristics of the
compressor to further refine the starting cycle on each recurring start.
If the compressor fails to start, the module will terminate the start attempt after 1 second and initiate a
3 minute lockout before attempting a restart.
While the compressor is running
, if supply voltage falls below the “shutdown on low voltage” limit for 2
seconds, SureStart will stop the compressor and initiate a 3 minute lockout. A restart will be initiated
after 3 minutes if the supply voltage is equal to or greater than the “minimum startup voltage”. This is
done to protect the compressor against a sudden drop in supply voltage.
SureStart is able to detect an interruption in power, when the interruption is 0.1 seconds or longer.
When a power interruption is detected, it will shut down the compressor for 3 minutes. A power
interruption that is shorter than 0.1 seconds may result in the compressor running backwards.
SureStart is able to determine if the compressor is running backwards. If this condition is detected,
the control will stop the compressor for 3 minutes before restart is initiated.
If the run capacitor is faulty or has failed, SureStart will shut down the compressor for 3 minutes
before initiating a restart.