Mcquay Hsa Screw Compressor Service Manual -

HSA compressors require specific viscosity (typically ISO VG 68 or 100) and additive packages. Automotive or standard refrigeration oil will cause carbonization at discharge valves. Manual solution: Part number lookup for OEM oil.

Search these sources using the exact model number from your unit's nameplate (e.g., HSA 123):

"McQuay HSA" filetype:pdf

Or:

site:daikinapplied.com HSA screw compressor manual

A matrix of “Problem – Cause – Solution.” Examples:

| Problem | Likely Cause (from manual) | Solution | | :--- | :--- | :--- | | High discharge temp | Low suction superheat or oil starvation | Check expansion valve, clean oil strainer | | No capacity control | Slide valve stuck or broken piston ring | Remove actuator, inspect slide valve bore | | Loud rattling noise | Worn rotor bearings or debris in rotors | Immediate teardown – do not restart | | Oil level dropping | Failed oil separator coalescer or leaking shaft seal | Replace separator element, replace shaft seal kit | mcquay hsa screw compressor service manual

If you tell me the full model number (e.g., HSA 150A, HSA 200B) and the specific service task (e.g., "replace oil filter" or "reset high pressure cutout"), I can give you generic screw compressor guidance that applies to McQuay HSA units.

The McQuay HSA Screw Compressor Service Manual is a technical guide designed for the installation, operation, and maintenance of single-screw compressors typically found in McQuay (now Daikin) air-cooled chillers. Key Manual Content

The manual focuses on ensuring optimal performance through precise maintenance and electrical setup. Core sections include:

Installation & Setup: Guidelines for proper clearance (typically around 5ft for maintenance access) and the use of spring vibration isolators to prevent mechanical fatigue. HSA compressors require specific viscosity (typically ISO VG

Electrical Connections: Detailed wiring diagrams and specifications for solid-state starters, including motor load amps and overload class settings.

Capacity Regulation: Information on the "stepless" capacity control system, which uses load/unload solenoid valves and a slide piston to match the building’s cooling load precisely from 100% down to roughly 12.5%.

Maintenance Procedures: Standard pumpdown protocols (suction pressure reached at 20 psig) and routine checks for oil levels and refrigerant charge. Service & Maintenance Checklist

Regular servicing is required to avoid common failures like overheating or part wear: "McQuay HSA" filetype:pdf

Oil System: HSA compressors use a high-hygroscopic synthetic polyolester (POE) oil (Part No. 735030446). Technicians must check the oil filter and ensure the oil sump—located at the base of the oil separator—maintains a proper charge.

Operational Logs: Service records should include normal refrigerant pressures and temperatures to help identify "errant behavior" early.

Protective Devices: Ensure water flow switches (paddle-type) and freeze protection are functioning to prevent "slugging" the compressor on start-up. Troubleshooting Guide

Common issues addressed in the service documentation include: McQuay HSA Screw Compressor Manual | PDF - Scribd

| Symptom | Possible Cause | Manual Reference Section | |--------|----------------|--------------------------| | High oil consumption | Worn gaterotor / oil separator | Section 6.4 | | Low capacity | Slide valve stuck | Section 5.2 | | High discharge temp | Low refrigerant charge / oil cooler issue | Section 4.1 | | Noisy operation | Bearing wear or star wheel damage | Section 7.0 (Teardown) | | Oil foaming | Liquid refrigerant in sump | Section 3.1 (Superheat adjustment) |