Goodmans SSZ, GSZ, ASZ, SSX, ASX, DSZ, DSX, GSX AIR Handler External Static, Initial System Charging

SERVICING

Mounting the condensing unit above the evaporator coil will require oil traps at equal intervals along the suction line. Install 1 oil trap for a height difference of 15-25 feet between indoor and outdoor units.

Install 2 oil traps for a difference of 26-50 feet, 3 for 51-100 feet, and 4 for 101-150 feet.

Fig 7. Oil Trap Placement

Oil Trap Construction

Long Radius Street Ell

45 °

Ell

45°

Street

Ell

Short Radius

Street Ell

Fig 8. Oil Trap

4.Low voltage wiring. Verify low voltage wiring size is adequate for the length used since it will be increased in a long line application.

Initial System Charging

R-410A condensers are factory charged for 15 feet of line set. To calculate the amount of extra refrigerant (in ounces) needed for a line set over 15 feet, multiply the additional length of line set by 0.6 ounces. Note for the formula below, the linear feet of line set is the actual length of liquid line (or suction line, since both should be equal) used, not the equivalent length calculated for the suction line.

Use subcooling as the primary method for final system charging of long line set system application.

Extra refrigerant needed =

(Linear feet of line set – 15 ft.) x X oz./ft.

Where X = 0.6 for 3/8" liquid tubing

Remember, 3/8" liquid tubing is required for all long line set applications.

Heat pumps should be checked in both heating and cooling mode for proper charge level. This guideline is meant to provide installation instructions based on most common long line set applications. Installation variables may affect system operation.

Follow the charging procedures in the outdoor unit I/O manual to ensure proper superheat and sub-cooling levels, especially on a system with a TXV installed in the indoor unit. Heat pumps should be checked in both heating and cooling mode for proper charge level. This guideline is meant to provide installation instructions based on most common long line set applications. Installation variables may affect system operation.

NO ADDITIONAL COMPRESSOR OIL IS NEEDED FOR LONGLINESETAPPLICATIONSONRESIDENTIALSPLIT SYSTEMS.

S-202 DUCT STATIC PRESSURES AND/OR STATIC PRESSURE DROP ACROSS COILS

This minimum and maximum allowable duct static pressure for the indoor sections are found in the specifications section.

Tables are also provided for each coil, listing quantity of air (CFM) versus static pressure drop across the coil.

Too great an external static pressure will result in insufficient air that can cause icing of the coil. Too much air can cause poor humidity control and condensate to be pulled off the evaporator coil causing condensate leakage. Too much air can also cause motor overloading and in many cases this constitutes a poorly designed system.

S-203 AIR HANDLER EXTERNAL STATIC

To determine proper air movement, proceed as follows:

1.Using a draft gauge (inclined manometer), measure the static pressure of the return duct at the inlet of the unit, (Negative Pressure).

2.Measure the static pressure of the supply duct, (Positive Pressure).

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