Issue:
1A9 diagnostic (EXV Elec Drive Ckt- Rfgt Ckt 1)
1AA diagnostic (EXV Elec Drive Ckt- Rfgt Ckt 2)
Resolution:
The 1A9 and 1AA diagnostic codes reliably report a wiring or expansion valve drive motor problem. Resistance measurements should show about 40 ohms between the black wire to the expansion valve and each of the other three wires. If that is O.K., there will often be a ground in the wires - disconnect the AMP header plug from the 1U3 module and measure the resistance of the four wires to ground - resistance should be near infinity.
The 70-125 ton RTAA, RTWA, and RTUA will not show the 1AA/1A9 diagnostic code. Their diagnostic will read EXV Elec Drive Ckt- Rfgt Ckt 1 or 2.
Notes:
Refer to RTAA-SB-5, RTAA-SB-9 or RLC-SVD03A-EN for more troubleshooting information.
Changes:
Other Question/Problem/Cause Statements:
- 1A9 diagnostic (EXV Elec Drive Ckt- Rfgt Ckt 1)
- 1AA diagnostic (EXV Elec Drive Ckt- Rfgt Ckt 2).
- Expansion valve drive motor
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-83027
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.