Lennox International Inc Merit Series Air Conditioner, 506945-01 Leak Test and Evacuation

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STEP 3 -- LEAK TEST AND EVACUATION

LEAK TEST

LOWHIGH

MANIFOLD GAUGE SET

B

A

TO VAPOR

SERVICE VALVE (ANGLE OR BALL TYPE)

 

NITROGEN

OUTDOOR UNIT

 

 

CONNECT GAUGE SET

 

HFC-410A

1A Connect the high pressure hose of an HFC-410A manifold gauge set to the vapor valve service port.

NOTE — Normally, the high pressure hose is connected to the liquid line port. However, connecting it to the vapor port better protects the manifold gauge set from high pressure damage.

BWith both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of the manifold gauge set.

NOTE — Later in the procedure, the HFC-410A container will be replaced by the nitrogen container.

2After the line set has been connected to the indoor and outdoor units, check the line set connections and indoor unit for leaks. Use the following procedure to test for leaks:

TEST FOR LEAKS

AWith both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of the manifold gauge set. Open the valve on the HFC-410A cylinder (vapor only).

BOpen the high pressure side of the manifold to allow HFC-410A into the line set and indoor unit. Weigh in a trace amount of HFC-410A. [A trace amount is a maximum of two ounces (57 g) refrigerant or three pounds (31 kPa) pressure.] Close the valve on the HFC-410A cylinder and the valve on the high pressure side of the manifold gauge set. Disconnect the HFC-410A cylinder.

CConnect a cylinder of nitrogen with a pressure regulating valve to the center port of the manifold gauge set.

DAdjust nitrogen pressure to 150 psig (1034 kPa). Open the valve on the high side of the manifold gauge set in order to pressurize the line set and the indoor unit.

EAfter a few minutes, open one of the service valve ports and verify that the refrigerant added to the system earlier is measurable with a leak detector.

FAfter leak testing, disconnect gauges from service ports.

FIGURE 11

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13ACX SERIES

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Contents Setting the Unit -- Clearances GeneralMinimum Clearance Between TWO Units Unit Dimensions Inches MM Setting the Unit CONTIN­ UED -- Unit PlacementUnit Dimensions PlacementRefrigerant Line SET Installing InstallationRefrigerant Line SET Installing Horizontal Runs Vertical Runs NEW Construction ShownLiquid Line Filter Drier Installation Typical Liquid Line Filter Drier InstallationRefrigerant Line SET Inches MM 2CONNECT Gauges and Equipment for Flushing Procedure 1CUT and Debur Refrigerant Piping -- Brazing ProceduresFlow Nitrogen Wrap Service Valves6BRAZE Line SET 7PREPARATION for Next StepIndoor Expansion Valve Installation Refrigerant Piping -- Installing Indoor Expansion ValveSensing Bulb Installation Equalizer Line InstallationLeak Test Leak Test and EvacuationOpen both manifold valves and start the vacuum pump EvacuationSize Circuit and Install Service Disconnect Switch Electrical -- Circuit Sizing and Wire RoutingInstall Thermostat 24VAC TransformerRouting High VOLTAGE, Ground and Control Wiring Electrical -- High Voltage and Field Control WiringHigh Voltage / Ground Wires Field Control Wiring Operating Manifold Gauge SET and Service ValvesTorque Requirements Homeowners Information Checking and Adding System Refrigerant13ACX Start-Up and Performance Checklist Cooling ModeStart UP Checks