To Next PageTo Next PageHow to fix low pressure in Gast Air Compressor?
If your Gast Air Compressor has low pressure, the most likely cause is a dirty filter. You should clean or replace the filter to resolve this issue.
Why is my Gast Air Compressor overheating?
If your Gast Air Compressor is overheating, there are several potential causes. First, ensure that there is sufficient voltage supply. Second, a leaky relief valve could be the problem, in which case you should replace the relief valve. Finally, check the wiring diagram and line voltage to make sure the motor is wired correctly.
What to do if Gast 120R has high pressure?
If your Gast Air Compressor is experiencing high pressure, it might be due to a dirty muffler. Try to clean or replace the muffler.
Why Gast 120R Air Compressor has low vacuum?
If your Gast Air Compressor has low vacuum, several issues could be the cause. It could be due to dirty, bent, or damaged valves, in which case you should clean or replace the valves. A damaged or worn cup might also be the problem, so replace the cup. Other potential causes include a leaky hose (replace the hose) or a plugged vacuum or pressure line (unplug the line).
How to reduce excessive noise in Gast 120R?
If your Gast Air Compressor is making excessive noise, it might be due to a leaky check valve. Replace the check valve to resolve the issue.
Safety instructions to prevent electrical shock during installation.
Essential safety precautions for electrical grounding and wiring.
Guidance for connecting the product using a power supply cord.
Requirements for connecting the unit via permanent wiring.
Guidelines for selecting and using appropriate extension cords.
Procedures for safely starting the compressor and troubleshooting initial issues.
Safety measures for electrical shock prevention during maintenance.
Precautions against burns and other injuries from hot surfaces and air streams.
Safety instructions for electrical shock prevention during kit installation.
Safety instructions to prevent electrical shock during installation.
Essential safety precautions for electrical grounding and wiring.
Guidance for connecting the product using a power supply cord.
Requirements for connecting the unit via permanent wiring.
Guidelines for selecting and using appropriate extension cords.
Procedures for safely starting the compressor and troubleshooting initial issues.
Safety measures for electrical shock prevention during maintenance.
Precautions against burns and other injuries from hot surfaces and air streams.
Safety instructions for electrical shock prevention during kit installation.
This document serves as the Operation and Maintenance Manual for the Gast 120R Rocking Piston Oil-less Air Compressor, identified by Part No. 70-7100 (Rev A). It provides comprehensive instructions for the safe and effective use, installation, and upkeep of the product. The manual emphasizes adherence to safety protocols, proper installation techniques, and regular maintenance to ensure years of trouble-free service.
The Gast 120R is an oil-less air compressor designed to pump only clean, dry air. Its oil-less design means it requires no lubrication, simplifying maintenance and preventing oil contamination in the air stream. The compressor is intended for operation within a temperature range of 32°F to 104°F (0°C to 40°C). It is crucial to protect the unit from dirt and moisture to maintain its performance and longevity. The compressor is not designed for pumping flammable or explosive gases, nor should it be used in atmospheres containing such gases. Exhaust air from the unit can become very hot, necessitating protection for surrounding items. Corrosive gases, particulate material, water vapor, oil-based contaminants, or other liquids can damage the unit, and therefore, must be filtered out if present in the air supply. For high-altitude applications, consulting a Gast Distributor/Representative is recommended.
The Gast 120R compressor is designed for installation on a horizontal surface. To minimize noise and vibration, it should be mounted to a stable, rigid operating surface using the supplied shock mounts. The unit comes with adjustable mounting feet, allowing for adjustments to the mounting pattern by loosening the vibration mounts and sliding the mounting bracket. Once adjusted, the vibration mounts must be secured to the body and mounting bracket before attaching the compressor to the application. Optional mounting orientations may be available, and users should consult the factory or a distributor for details.
For plumbing, plugs must be removed from the IN and OUT ports. Connections should be made using pipes and fittings that are the same size or larger than the product's threaded ports. It is essential to connect the intake and exhaust plumbing to the correct inlet and outlet ports, as the ports are not designed to support plumbing weight.
The product includes an external intake and exhaust muffler for adequate filtration in most applications. Filters should be checked periodically and replaced as necessary, with a recommendation to consult a Gast Distributor/Representative for additional filter options. Relief valves and gauges should be installed at either the inlet or outlet, or both, to monitor performance. Check valves may be required to prevent back streaming into the pump.
Regarding motor control, it is the user's responsibility to ensure that the electrical installation is adequate and conforms to all national and local codes and ordinances. The metal capacitor must be grounded. The correct overload setting for motor protection should be determined based on the motor starter manufacturer's recommendations. Fuses, motor protective switches, or thermal protective switches should be selected for protection. Fuses provide short-circuit protection, not overload protection, and incoming line fuses must withstand the motor's starting current. Motor starters with thermal magnetic overload or circuit breakers protect against overload or reduced voltage conditions. The product's wiring diagram provides necessary electrical information, and the power source must be correct for dual-voltage motors.
For models with a power supply cord, the product must be grounded. For 220/240-volt circuits, the power supply cord grounding plug should be connected to a matching grounded outlet, and adapters should not be used. Grounding reduces the risk of electric shock in the event of a short circuit. The plug must be properly installed and grounded according to local codes. If grounding instructions are unclear, or if there is uncertainty about proper grounding, a qualified electrician or serviceman should be consulted. The plug should not be modified.
For permanently wired models, the product must be connected to a grounded, metallic, permanent wiring system, or an equipment grounding terminal or lead on the product. Power supply wiring must conform to all required safety codes and be installed by a qualified person. The supply voltage must match the product nameplate.
Extension cords, if used, must be 3-wire with a 3-blade grounding plug and connected to a matching 3-slot receptacle. Adapters should not be used. The extension cord must be in good condition and of the correct wire gauge to carry the product's current draw. An undersized cord poses a fire hazard and can lead to overheating due to voltage drop. A table in the manual provides minimum gauge requirements for extension cords based on amperage, voltage, and length. When in doubt, a heavier gauge cord should be used (smaller gauge number indicates heavier wire).
During operation, proper safety guards must be installed, and fingers and objects kept away from openings and rotating parts. Motor terminal covers, if provided, must be in place. Product surfaces can become very hot during operation, so they should be allowed to cool before handling. The air stream may contain solid or liquid material, necessitating proper eye protection. Hearing protection is recommended as the motor sound level may exceed 70 dBA. The product should be operated at recommended pressures or vacuum duties and room ambient temperatures, and should not be started against a vacuum or pressure load. If the motor fails to start or slows down under load, it should be shut off and disconnected from the power supply. The voltage, motor direction, plug, cord, and switch should be checked for damage. If equipped with a thermal protection switch, the motor may restart after cooling.
Regular maintenance is crucial for the Gast 120R compressor. Before performing any maintenance, the electrical power supply must be disconnected. If the product is hard-wired, the electrical power must be disconnected at the circuit breaker or fuse box. All air lines must be vented to release pressure or vacuum. Failure to follow these instructions can result in death, fire, or electrical shock.
Product surfaces become very hot during operation and should be allowed to cool before handling. The air stream may contain solid or liquid material, so proper eye protection is necessary during maintenance. The product should be cleaned in a well-ventilated area. Failure to follow these instructions can result in burns, eye injury, or other serious injury.
It is the user's responsibility to regularly inspect and make necessary repairs to maintain proper operation. Pressure must be released from the product before starting maintenance. Intake and exhaust filters should be checked after the first 500 hours of operation. Filters should be cleaned and their checking frequency determined for future operation, as this procedure helps assure product performance and service life.
The maintenance procedure involves:
For shutdown procedures, it is important to follow proper steps to prevent product damage. Oil should never be added to this oil-less pump. Proper shutdown prevents premature pump failure, as the ferrous metals or aluminum construction is susceptible to rust and corrosion when pumping condensable vapors like water. The steps are:
Gast offers several Service Kits for the 120R compressor, including:
For service kit installation, the electrical power to the pump must be disconnected, and all air lines vented. Individual kit instructions should be consulted for component installation. All external accessories like relief valves and gauges must be checked for damage before operating the product. If the pump still does not produce proper vacuum or pressure after maintenance, the unit should be sent to a Gast Authorized Service Facility for repair. Gast does not guarantee field-rebuilt product performance; for performance guarantees, the product must be returned to an authorized service facility.
A troubleshooting chart is provided to help diagnose common issues such as low pressure, high pressure, low vacuum, excessive noise, overheating, and failure to start, linking them to possible causes like dirty filters, dirty mufflers, damaged valves, leaky hoses, or incorrect wiring. A service and maintenance chart is also included for recording dates, problems, technicians, and notes for tracking maintenance history.
General| Model | 120R |
|---|---|
| Voltage | 115/230 VAC |
| Phase | 1 |
| Weight | 16 lb |
| Noise Level | 72 dB |
