| Inhibit Displayed | Reason for Inhibit | UCM's Reaction | Reset Conditions |
|---|---|---|---|
Disabled by Contractor / Drive Fail Input: Ckt Compressor Proving Input | Problem: The circuit's proving input of the affected circuit has opened, due to one or more of the electromechanicial devices located in the main 115vac control has tripped or experienced a failed condition, prior to a compressor being commanded ON. Check: Compressor contactor and switch, high pressure cutout switch, compressor protection devices, breakers, fuses, wiring, etc. | All compressors and condenser fans on the affected circuit will be disabled. | The compressors on the affected circuit will remain OFF on a manual lockout. |
Contactor/Drive Fail
This diagnostic indicates that compressor proving input at the SCM/MCM was closed when the unit was NOT actively calling for compressor operation. This generally is a sign of a faulty contactor, the compressor proving NO auxiliary switch is sticking or compressor proving wires are mistakenly wired to the NC contacts. This alarm can also be generated if a service technician manually engages the compressor contactor while troubleshooting.
Example: IPAK 1 with MCM
Text in the image above.
23VDC when Input is open and 0 VDCwhen Input closes.
23VDC when Input is open and 0 VDC when Input closes.
Notes: Compressor Contactor Fail
This diaagnostic is generated when the uni is NOT calling for the compressor but sees the Compressor Proving Input closed (0VDC). This is generally caused by sticking auxiliary switch, welded contactor, new contactor aux wired to NC instead of NO or someone has manually engaged the compressor’s contactor.
On units with a Variable Speed Compressor it will be an indication that the K42 relay is faulty or compressor proving is mis-wired to the NC terminals 4,6 terminals.
Text in the image above.
Device Prefix Location Code
Area
Location
1
Inside Unit Control Box 2
Condenser SEction 3
Inside Secondary Control Box 4
Heat / Extended Casing Section 5
Supply Fan Section 6
Evap Section 7
Damper Filter Section 8
Exhaust Return Fan Section 9
External Field MTO Device Pre-Symbio 800 VSC Compressor Proving Input
IMPORTANT!
Do not energize unit until check-out and start-up procedure has been completed.
CAUTION
If any of the existing wiring as supplied with the appliance must be replaced. It must be replaced with wiring rated for 105°C or it equivalent. Notes:
- Unless otherwise noted all switches are shown at 25°C (77°F) at atmosphere pressure. At 50% relative humidity, with all utilities turned off, and after a normal shutdown has occurred.
- All field wiring must be in accordance with the Nation Electric Code (NEC), stat and local requirements.
- 1J171, 1J172, 1J173, 1J176, 1TB18, 1TB10, 1U16, 1U128, 1U3 and associated wiring connections are located in the main unit control box. Schematic wiring shown here for reference only.
- 2L21, 2586 & associated wiring connections are located in the condenser section. Schematic wiring shown here for reference only.
Refer to your unit's schematic for your specific wire locations.
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.