Mcquay Hsa Screw Compressor Service Manual Here

The slide valve is often a point of failure, and issues usually arise from its solenoid controls or the sensor (potentiometer) that reports its position.

: Check the load/unload solenoid valves for electrical continuity and mechanical sticking. mcquay hsa screw compressor service manual

Measure resistance between phases (U-V, V-W, W-U). Resistance values must be balanced within ±2%. The slide valve is often a point of

Oil pump (manual or electric) and clean oil sampling containers. Resistance values must be balanced within ±2%

Remedy: Check for air contamination by comparing standing pressures to saturated pressure-temperature charts. Purge non-condensables if necessary. Symptom: Slide Valve Fails to Load/Unload Defective load/unload solenoid valves.

The original HSA compressors are aging (some units are 20+ years old). However, Daikin Applied continues to support them. In 2018, Daikin released , which updates several procedures in the original manual:

Low oil level or failed oil cooler.High compression ratio (high head pressure).Leaking internal relief valve.