Goodman Mfg R-410A manual Refrigeration Repair Practice, Leak Testing Nitrogen or NITROGEN-TRACED

SERVICING

WARNING

1.Disassemble and remove the heating element(s).

2.Visually inspect the heater assembly for any breaks in the wire or broken insulators.

3.Using an ohmmeter, test the element for continuity - no reading indicates the element is open. Replace as neces- sary.

S-100 REFRIGERATION REPAIR PRACTICE

ALWAYS REMOVE THE REFRIGERANT CHARGE IN A PROPER MANNER BEFORE APPLYING HEAT TO THE SYSTEM.

These models use the FasTest Access Fitting System, with a saddle that is either soldered to the suction and liquid lines or is fastened with a locking nut to the access fitting box (core) and then screwed into the saddle. Do not remove the core from the saddle until the refrigerant charge has been removed. Failure to do so could result in property dam- age or personal injury.

When installing a new core or reinstalling the core after re- moval, it is very important to note that before inserting the core into the saddle, the core and saddle must be free of debris and the “O” Ring must have a thin coating of refrigerant oil applied to it. The oil is to prevent the “O” Ring from being deformed when the core is tightened completely. The core should be torqued to 8 ft. lb.

When repairing the refrigeration system:

1.Never open a system that is under vacuum. Air and mois- ture will be drawn in.

2.Plug or cap all openings.

3.Remove all burrs and clean the brazing surfaces of the tubing with sand cloth or paper. Brazing materials do not flow well on oxidized or oily surfaces.

4.Clean the inside of all new tubing to remove oils and pipe chips.

5.When brazing, sweep the tubing with dry nitrogen to pre- vent the formation of oxides on the inside surfaces.

6.Complete any repair by replacing the liquid line drier in the system, evacuate and charge.

At any time the system has been open for repair, the factory installed liquid line filter drier must be replaced.

BRAZING MATERIALS

Copper to Copper Joints - Sil-Fos used without flux (alloy of 15% silver, 80% copper, and 5% phosphorous). Recommended heat 1400°F.

Copper to Steel Joints - Silver Solder used without a flux (alloy of 30% silver, 38% copper, 32% zinc). Recommended heat - 1200°F.

S-101 LEAK TESTING

(NITROGEN OR NITROGEN-TRACED)

TO AVOID THE RISK OF FIRE OR EXPLOSION, NEVER USE OXYGEN, HIGH PRESSURE AIR OR FLAMMABLE GASES FOR LEAK TESTING OF A REFRIGERATION SYSTEM.

TO AVOID POSSIBLE EXPLOSION, THE LINE FROM THE NITROGEN CYLINDER MUST INCLUDE A PRESSURE REGULATOR AND A PRESSURE RELIEF VALVE. THE PRESSURE RELIEF VALVE MUST BE SET TO OPEN AT NO MORE THAN 150 psig.

Pressure test the system using dry nitrogen and soapy water to locate leaks. If you wish to use a leak detector, charge the system to 10 psi using the appropriate refrigerant then use nitrogen to finish charging the system to working pressure, then apply the detector to suspect areas. If leaks are found, repair them. After repair, repeat the pressure test. If no leaks exist, proceed to system evacuation.

S-102 EVACUATION

REFRIGERANT UNDER PRESSURE!

FAILURE TO FOLLOW PROPER PROCEDURES MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.

This is the most important part of the entire service procedure. The life and efficiency of the equipment is dependent upon the thoroughness exercised by the serviceman when evacuating air (non-condensable) and moisture from the system.

Air in a system causes high condensing temperature and pres- sure, resulting in increased power input and reduced perfor- mance.

34