Issue:
Solution Pump Control
Resolution:
The Chiller solution pump has 2 selectable modes of operation:
- AUTO - The solution pump output will be controlled based on the normal unit operating mode. While the solution pump mode is set to AUTO, and no overriding conditions exist, the solution pump output shall normally be energized except under the following conditions:
- When the unit is stopped (Unit Stop, External Auto Stop, or Emergency Stop).
- During unit Power On Delay Time.
- When Primary Control States are Ice Rebuild Delay or Ice Build Complete.
- ON - The solution pump output will always be energized and the solution pump will run continuously. Only Service Test or Emergency Stop will override this mode and de-energize the solution pump output.
A Solution Pump Off Delay Time may be set to allow the solution pump output to remain energized for a selectable period of time (30 to 600 seconds) after a call for the solution pump to be shut off. Only Emergency Stop will bypass this delay.
The Low Ambient Pump On Control function will energize the solution pump output when the outside air temperature falls below a selectable Low Ambient Pump On Temperature Setpoint (-20 to 50 degrees) or the Outside Air Temperature input failure diagnostic is present. An Auto Reset diagnostic will be generated while this condition exists. This mode has priority over all other operational modes with exception of Emergency Stop. If a low ambient condition exists while the user attempts to de-energize the solution pump output during service test operation, a message will be displayed advising that the pump cannot be turned off due to the low ambient condition.
Notes:
If the pump is controlled by an external Building Automation System, then the pump control should be set to "on". If not, an Evaporator Solution Flow Loss diagnostic will be generated as the chiller is looking for the chiller flow proving switch to be in the open position prior to starting the pump.
Changes:
Other Question/Problem/Cause Statements:
- Solution Pump Control
Facts:
- Intellipak Air-Cooled Chiller 20-60
- Air-Cooled Chiller - Intellipak (CGAC, CGAF)
Document Identifier: DOC-77040
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.