Applicable Systems
YVAA
Symptoms
System pressure has dropped below the low-pressure safety limit. The unit has shut down to prevent evaporator freeze damage.
Possible Causes
- Refrigerant charge insufficient due to leak
- Expansion valve restricted or failed
- Evaporator water flow reduced or blocked
Troubleshooting Steps
- Step 1: Check refrigerant charge level and inspect for leaks
Charge level correct, no leaks found - Step 2: Inspect expansion valve operation and superheat
Expansion valve operating within specification - Step 3: Verify evaporator water flow rate and pump operation
Flow rate meets design requirements
How to Reset
To reset: Reset the low-pressure switch after restoring adequate suction pressure.
Source: York YVAA Chiller Manual, Johnson Controls/York
Category: Chiller