Leak Detection
Visible oil spots, residue, or stains on refrigerant lines and fittings usually indicate this problem.
What is a refrigerant leak?
The full system charge threshold that subjects commercial and comfort cooling systems to mandatory EPA repair rules.
What is 50 pounds?
The deep vacuum level in microns that non-leaking systems must reach before recharging to ensure moisture and air are fully removed.
What is 500 microns?
The phase of refrigerant that should be recovered first to speed up the recovery process.
What is liquid?
The state that zeotropic (400-series) refrigerant blends like R-410A must be removed from the cylinder to prevent fractionation.
What is liquid?
The inert gas that must be used to pressurize a system for leak detection, using soap bubbles or ultrasonic sensors.
What is dry nitrogen?
he annual leak rate threshold that triggers mandatory repairs for commercial refrigeration appliances containing 50 or more pounds.
What is 20%?
The required recovery vacuum level for medium-pressure appliances containing less than 200 pounds of refrigerant using equipment manufactured after Nov 15, 1993.
What is 10 inches of mercury (10" Hg vacuum)?
Connecting service hoses to both of these system ports simultaneously reduces recovery time and prevents pressure drops across restrictions.
What are the high side (liquid line) and low side (suction line)?
The manual service valve position that isolates the gauge service port while allowing normal flow through the system.
What is back-seated?
The only ozone-depleting refrigerant that the EPA permits to be used in trace amounts mixed with nitrogen for electronic leak detection.
What is HCFC-22 (R-22)?
The annual leak rate threshold that triggers mandatory repairs for comfort cooling appliances containing 50 or more pounds.
What is 10%?
The required recovery vacuum level for medium-pressure appliances containing 200 pounds or more of refrigerant using post-1993 equipment.
What is 15 inches of mercury (15" Hg vacuum)?
The specialized recovery method that uses the system's own compressor or pressure to push liquid into a recovery cylinder.
What is the push-pull recovery method?
The service accessory that must be used when adding liquid refrigerant into the suction line of an operating system to prevent compressor slugging.
What is a metering/orifice charging device (or throttling manifold hand valve)?
The maximum allowable test pressure when leak testing a system with a hermetic compressor to prevent catastrophic shell rupture.
What is 150 psig (or the low-side nameplate design pressure)?
The timeframe a technician has to repair a leaking system and conduct an initial verification test once the leak threshold is exceeded.
What is 30 days?
The required recovery level when evacuating a system known to have leaks before opening it for repair.
What is 0 psig (atmospheric pressure)?
The component that must always be installed on the inlet of a recovery machine to protect it from acids, carbon, and foreign debris.
What is an in-line filter-drier?
The condition indicated when the suction line freezes all the way back to the compressor due to reduced heat absorption.
What is severely restricted evaporator airflow (or a frozen evaporator coil)?
The specific reason oxygen or compressed air must never be used to pressurize a system for leak checks
What is the risk of an explosion when mixed with compressor oil?
The follow-up test that must be performed within 10 days of returning the repaired system to normal operating conditions.
What is a follow-up verification test?
What a technician should do if a system pulled into a vacuum experiences an immediate rise in pressure that stops and holds steady below atmospheric pressure.
What is continue evacuation (residual liquid moisture is still boiling off)?
Under EPA regulations, the four components that constitute a "major maintenance, service, or repair."
What are the compressor, condenser, evaporator, and auxiliary heat exchanger coil?
The method used to calculate the required field refrigerant charge adjustment for split systems when the line set exceeds the factory-assumed length.
What is multiplying the extra line footage by the manufacturer's liquid line charge allowance (oz/ft)?