Rockwell Automation 20L-LL PowerFlex 700L Liquid-to-Liquid Heat Exchanger - Manual (Page 27)

PowerFlex 700L Liquid-to-Liquid Heat Exchanger User Manual
Publication 20L-UM002A-EN-P
Chapter
2
Operation
This chapter provides information on operating the PowerFlex 700L
Liquid-to-Liquid Heat Exchanger.
Drive Interaction Normal Operation
Communications between the drive and the heat exchanger consist of a run
output signal from the drive and an interlock output to the drive. The heat
exchanger’s run input is controlled by a normally-open relay output from
the drive. The heat exchanger interlock relay is de-energized when a fault
occurs or power is not present.
The STATUS indicator flashes (slow) green when the heat exchanger is
ready to operate and its interlock relay is energized.
Immediately following a valid start sequence in the drive, the drive’s run
contact closes, signaling the coolant controller to begin operating the heat
exchanger. The coolant pump starts, the STATUS indicator changes to
steady green, and coolant flow is monitored.
When the drive is stopped, the heat exchanger continues to run for
approximately 2 minutes and the STATUS indicator flashes (fast) green to
indicate that the heat exchanger is in a cool down period.
Loss of Flow Operation
If the flow sensor fails to detect flow for more than 10 seconds, the STATUS
indicator flashes red to indicate a fault and the pump stops. The interlock
relay and STATUS indicator remain in this state until the run output signal
from the drive is turned off. Thereafter, the STATUS indicator flashes red at
a slower rate to indicate the heat exchanger experienced a loss of flow but is
now ready to operate.
Asserting the run input after correcting a heat exchanger fault restarts the
heat exchanger and the STATUS indicator changes to steady green.
For information on… See page…
Drive Interaction 2-1
PRIME SWITCH Operation 2-2
Operating Status Indications 2-2
Adding Coolant to the Drive Loop for Start-Up 2-3
Draining Coolant from the Drive Loop for Periodic Replacement 2-5
Draining Supply Side Cooling Loop for Periodic Maintenance 2-4