Installation Guide
Tools Needed:
- Adjustable wrench set
- Socket set
- Screwdrivers (flat and Phillips)
- Torque wrench
- Level
- Pipe thread sealant
Step-by-Step Installation
- Select Location: Choose a clean, dry, well-ventilated area with adequate space for maintenance access and proper air circulation.
- Foundation Preparation: Place compressor on a solid, level concrete floor or vibration isolation pads to minimize noise and vibration.
- Electrical Connection: Connect to appropriate power supply (see specifications). Ensure proper grounding and circuit protection.
- Air System Connection: Install air lines using properly sized piping with downward slope for moisture drainage.
- Pressure Relief Valve: Ensure pressure relief valve is properly installed and unobstructed.
- Oil Check: Verify proper oil level in crankcase before initial startup.
- Initial Startup: Run compressor without load for 30 minutes to break in components, then check for leaks and proper operation.
Specifications
| Model Series | QT-350 |
| Type | Reciprocating Piston Air Compressor |
| Configuration | Two-Stage, Air-Cooled |
| Horsepower | 7.5 HP |
| Air Delivery (CFM) | 24.1 CFM at 175 PSI |
| Maximum Pressure | 175 PSI |
| Tank Capacity | 80 Gallons (Vertical) |
| Noise Level | 78 dB(A) at 1 meter |
| Power Requirements | 230V, 60Hz, Single Phase, 30A |
| Dimensions (HxWxD) | 72 x 30 x 30 inches |
| Weight | 420 lbs |
| Oil Capacity | 2.5 Quarts |
Warranty Information
- Compressor Pump: 5 years limited warranty
- Tank: Lifetime limited warranty
- Parts & Labor: 1 year full coverage
- Motor: 2 years limited warranty
For warranty service, contact Quincy Compressor Customer Service at 1-800-543-HELP or visit QuincyCompressor.com
Key Features
Two-Stage Compression
Dual-stage operation provides greater efficiency and cooler operating temperatures, resulting in longer component life and reduced maintenance.
Pressure Lubrication System
Full pressure lubrication ensures all moving parts receive proper oil flow, reducing wear and extending compressor life.
Cast Iron Construction
Heavy-duty cast iron cylinders and crankcase provide superior durability, heat dissipation, and vibration dampening.
Thermal Protection
Built-in thermal overload protection prevents motor damage from overheating during extended operation.
ASME Certified Tank
80-gallon ASME certified air tank meets highest safety standards and includes lifetime warranty.
Low RPM Operation
Operating at lower RPM (870) reduces wear, noise, and heat generation compared to higher-speed compressors.
Performance Specifications
CFM at 100 PSI
28.5 CFM - Ideal for continuous tool operation
CFM at 150 PSI
25.3 CFM - Suitable for industrial applications
Duty Cycle
100% - Capable of continuous operation
Recovery Time
2.5 minutes from 100-175 PSI
Oil Change Interval
500 hours or 6 months of normal use
Air Outlet
1/2" NPT - Standard industrial connection
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Compressor won't start | Power issue, pressure switch fault, thermal overload | Check power supply, reset overload, test pressure switch |
| Low pressure output | Worn valves, leaking gaskets, intake restriction | Check valve plates, inspect gaskets, clean air filter |
| Excessive noise/vibration | Loose components, worn bearings, improper mounting | Tighten all fasteners, check bearings, verify level installation |
| Overheating | Dirty cooling fins, low oil, restricted ventilation | Clean cooling surfaces, check oil level, improve airflow |
| Oil in air lines | Worn piston rings, overfilled oil, wrong oil type | Check rings, drain excess oil, use recommended oil |
| Frequent cycling | Air leaks, faulty check valve, undersized tank | Check for leaks, test check valve, verify application requirements |
Maintenance Codes & Indicators
- Red Oil Light: Low oil pressure - Check oil level and pump immediately
- Yellow Service Light: Scheduled maintenance due - Refer to maintenance schedule
- Continuous Blinking: Thermal overload - Allow to cool and reset
- Pressure Gauge Fluctuation: Valve issue - Inspect and replace valves if necessary
- Unusual Knocking: Bearing wear - Inspect connecting rods and bearings
- Slow Pressure Build: Worn rings - Perform compression test
Manual Downloads
QT-350 Series Manuals
QT-350-80V
7.5HP 80 Gallon Vertical
QT-350-60V
7.5HP 60 Gallon Vertical
QT-350-80H
7.5HP 80 Gallon Horizontal
QT-350-230V
7.5HP 230V Single Phase
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