Quincy 370 Air Compressor

User Manual & Installation Guide

Industrial Duty Compressor

Installation Guide

Tools Needed:

  • Adjustable wrench set
  • Level
  • Screwdrivers (flat and Phillips)
  • Pipe wrench
  • Pressure gauge
  • Teflon tape

Step-by-Step Installation

  1. Choose Installation Location: Select a well-ventilated area with solid, level concrete flooring and adequate clearance for maintenance access.
  2. Foundation Preparation: Ensure the foundation can support the compressor's weight and vibration. Use vibration pads if installing on non-concrete surfaces.
  3. Electrical Connection: Connect to appropriate power supply (see specifications). All electrical work must comply with local codes and be performed by a qualified electrician.
  4. Air System Connection: Install proper air lines using recommended piping materials. Include a main shut-off valve and drain legs in the piping system.
  5. Oil Check: Verify oil level is at proper mark on sight glass before initial startup.
  6. Pressure Settings: Set cut-in and cut-out pressures according to application requirements.
  7. Initial Startup: Perform initial startup without load, then gradually increase to full operating pressure while checking for leaks.
Warning: Installation must be performed by qualified personnel. Ensure proper ventilation to prevent carbon monoxide buildup from gasoline engines (if applicable).

Specifications

Model Series QT-370
Type Two-Stage Reciprocating Air Compressor
Power Source Electric / Gasoline Options
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 (Electric) 230V, 60Hz, 30A (Single Phase)
Dimensions (HxWxD) 72 x 36 x 42 inches
Weight 580 lbs (Empty)
Pump Type Two-Stage, Cast Iron

Warranty Information

  • Full Warranty: 2 years parts and labor
  • Pump Warranty: 5 years on cast iron pump
  • Tank Warranty: Lifetime limited warranty on ASME tank
  • Additional Coverage: Optional extended service plans available

For warranty service, contact Quincy Compressor Customer Service at 1-800-321-7000 or visit QuincyCompressor.com

Key Features

Two-Stage Compression

Delivers higher efficiency and cooler operation by compressing air in two stages, reducing moisture accumulation and increasing overall system reliability.

Cast Iron Construction

Heavy-duty cast iron pump and components provide superior heat dissipation, extended service life, and reduced maintenance requirements.

Pressure Lubricated Pump

Full pressure lubrication system ensures proper oil distribution to all critical components, reducing wear and extending pump life.

ASME Certified Tank

80-gallon ASME certified air receiver tank with safety valve and drain system for reliable, safe operation.

Thermal Protection

Built-in thermal overload protection prevents motor damage from overheating during extended operation or high ambient temperatures.

Low RPM Operation

Operating at lower RPMs reduces wear, noise, and heat generation while maintaining high air delivery efficiency.

Performance Specifications

Air Delivery

24.1 CFM at 175 PSI for continuous tool operation

Duty Cycle

100% duty cycle for continuous industrial operation

Pressure Range

Adjustable from 100-175 PSI for various applications

Recovery Time

Full tank recovery in under 3 minutes at 175 PSI

Oil Capacity

2.5 quart sump with easy-access fill port

Cooling System

Integrated cooling fins and fan for optimal heat dissipation

Troubleshooting

Problem Possible Cause Solution
Compressor won't start Power issue, pressure switch fault, thermal overload tripped Check power supply, reset thermal overload, inspect pressure switch
Low air pressure Air leaks, worn valves, intake filter clogged Check for leaks, inspect valves, clean or replace air filter
Excessive noise/vibration Loose components, worn bearings, improper mounting Tighten all fasteners, check bearings, ensure proper installation
Overheating Low oil, dirty cooling fins, high ambient temperature Check oil level, clean cooling fins, improve ventilation
Oil in air lines Worn piston rings, overfilled oil, wrong oil type Check piston rings, adjust oil level, use recommended oil
Excessive moisture Faulty drain valve, high humidity, inadequate aftercooling Check drain valve operation, install air dryer, ensure proper drainage

Common Error Indicators

  • Red Oil Light: Low oil pressure - Check oil level and pump immediately
  • Thermal Overload Trip: Motor overheating - Allow cool down, check ventilation
  • Pressure Switch Failure: Compressor won't cycle - Inspect pressure switch and contacts
  • Unloader Valve Issue: Hard starting - Check unloader valve operation
  • Belt Problems: Slipping or squealing - Adjust tension or replace belt
  • Check Valve Issue: Air leaking back - Inspect and replace check valve if necessary

Manual Downloads

Current Model Manuals

QT-370

7.5HP Two-Stage Industrial Compressor

QT-370E

7.5HP Electric Version

QT-370G

7.5HP Gasoline Version

QT-370V

Vertical Tank Configuration

Related Models

QT-250

5HP Two-Stage Compressor

QT-540

10HP Industrial Compressor

QR-370

Rotary Screw Version

QP-370

Portable Version with Trailer

Note: For models not listed here, please visit the Quincy Compressor Support Website for complete documentation and technical bulletins.