Issue:
The chilled water setpoint cannot be adjusted externally without the 1U2 (Options Module)
Resolution:
The 1U2 (Options Module) is required for for external chilled water and external current limit setpoints.
The external chilled water setpoint inputs are on TB1-3,4,5 (1U2) depending on your desired input; either 4-20mA, 2-10VDC, or variable resistance.
The external current limit setpoint inputs are on TB1-6,7,8 (1U2) depending on your desired input; either 4-20mA, 2-10VDC, or variable resistance.
- Navigate to Menu P3 and validate item 30 External Chilled Water Setpoint is set to "Enable".
- Validate the wiring is correct and that the polarity is correct. Positive is connected to TB1-4 and negative is connected to TB1-5 on the 1U2 module.
- Toggle the dip switch SW1-1 on the 1U2 module to make sure that it is not affected by any possible corrosion. Set this dip switch to the "OFF" position.
- Connect a 9 volt battery to TB1-4 and 5 as described above and look for a chilled water setpoint of approximately 57 degrees.
- If this value is not correct, then suspect a bad 1U2 module. If the setpoint is correct, then it may be possible that a the input has a grounding issue. A DC to DC voltage isolator may need to be installed.
Notes:
See individual chiller wiring diagrams.
Changes:
Other Question/Problem/Cause Statements:
- Can the chilled water setpoint be adjusted externally without the 1U2 (Communications Module)?
- External Chilled Water setpoint?
- External Current Limit Setpoint?
- Remote chilled water setpoint
- Remote setpoint
Facts:
- Air-Cooled Chiller (Pueblo) (RTAA 130-400 Ton)
- Air-Cooled Chiller (Pueblo) (RTAA 70-125 Ton)
- Compressor Chiller (Pueblo) (RTUA)
- Water-Cooled Chiller (Pueblo) (RTWA)
Document Identifier: DOC-82647
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.