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Page 13

14ACX SERIES

STEP 5 -- UNIT START-UP

IMPORTANT

If unit is equipped with a crankcase heater, it should be
energized 24 hours before unit start-up to prevent
compressor damage as a result of slugging.

1 - Rotate fan to check for binding.

2 - Inspect all factory- and field-installed wiring for loose

connections.

3 - After evacuation is complete, open the liquid line and

suction line service valve stems to release the
refrigerant charge (contained in outdoor unit) into the
system.

4 - Replace the stem caps and tighten to the value listed

in table 3.

5 - Check voltage supply at the disconnect switch. The

voltage must be within the range listed on the unit's
nameplate. If not, do not start the equipment until you
have consulted with the power company and the
voltage condition has been corrected.

6 - Connect manifold gauge set for testing and charging

using figure 10 as a guideline.

7 - Set the thermostat for a cooling demand. Turn on

power to the indoor indoor unit and close the outdoor
unit disconnect switch to start the unit.

8 - Recheck voltage while the unit is running. Power must

be within range shown on the unit nameplate.

9 - Check system for sufficient refrigerate using the

procedures outlined in under

 System Refrigerant

.

OPERATING MANIFOLD GAUGE SET AND SERVICE
VALVES

The liquid and suction line service valves are used for
removing refrigerant, flushing, leak testing, evacuating,
checking charge and charging.

Each valve is equipped with a service port which has a
factory-installed valve stem. Figures 15 and 16 provide
information on how to access and operate both angle- and
ball-type service valves.

Torque Requirements

When servicing or repairing heating, ventilating, and air
conditioning components, ensure the fasteners are
appropriately tightened. Table 3 lists torque values for
fasteners.

TABLE 3

TORQUE REQUIREMENTS

Parts

Recommended Torque

Service valve cap

8 ft.- lb.

11 NM

Sheet metal screws

16 in.- lb.

2 NM

Machine screws #10

28 in.- lb.

3 NM

Compressor bolts

90 in.- lb.

10 NM

Gauge port seal cap

8 ft.- lb.

11 NM

IMPORTANT

To prevent stripping of the various caps used, the
appropriately sized wrench should be used and fitted
snugly over the cap before tightening.

Using Manifold Gauge Set

When checking the system charge, only use a manifold
gauge set that features low loss anti-blow back fittings.

Manifold gauge set used with HFC-410A refrigerant
systems must be capable of handling the higher system
operating pressures. The gauges should be rated for use
with pressures of 0 - 800 psig on the high side and a low
side of 30” vacuum to 250 psig with dampened speed to
500 psi. Gauge hoses must be rated for use at up to 800
psig of pressure with a 4000 psig burst rating.

BALL (SHOWN
CLOSED)

SERVICE PORT

CORE

TO 

OPEN

 ROTATE STEM

COUNTERCLOCKWISE 90°.

TO 

CLOSE 

ROTATE STEM

CLOCKWISE 90°.

SERVICE PORT

SERVICE PORT

CAP

STEM CAP

VALVE
STEM

1 - Remove stem cap with an appropriately sized wrench.

2 - Use an appropriately sized wrenched to open. To open valve,

rotate stem counterclockwise 90°. To close rotate stem
clockwise 90°.

OPERATING BALL-TYPE SERVICE VALVE:

FIGURE 15

Summary of Contents for Merit 14ACX-018-230

Page 1: ...tdoor air conditioner is designed for use with HFC 410A refrigerant only This unit must be installed with an approved indoor air handler or coil See the Lennox 14ACX Product Specifications bulletin EH...

Page 2: ...ing or stowing the panels consider any weather conditions especially wind that may cause panels to be blown around and damaged NOTICE Roof Damage This system contains both refrigerantand oil Some rubb...

Page 3: ...e rises above 40 psig DO NOT REPLACE COMPRESSOR LIQUID LINE FILTER DRIER INSTALLATION The provided filter drier must be field installed in the liquid line between the outdoor unit s liquid line servic...

Page 4: ...THE LIQUID LINE TO THE SUCTION LINE FLOOR JOIST OR ROOF RAFTER REFRIGERANT LINE SET INSTALLING HORIZONTAL RUNS NOTE Similar installation practices should be used if line set is to be installed on ext...

Page 5: ...ndoor unit s liquid line orifice housing LOW HIGH EXISTING INDOOR UNIT GAUGE MANIFOLD CYLINDER CONTAINING CLEAN HCFC 22 TO BE USED FOR FLUSHING Positioned to deliver liquid refrigerant LIQUID LINE SER...

Page 6: ...d debur the ends The pipe must remain round Do not crimp end of the line Remove service cap and core from both the suction and liquid line service ports 1 2 ANGLE TYPE SERVICE VALVE SERVICE PORT CORE...

Page 7: ...WHEN BRAZING LINE SET TO SERVICE VALVES POINT FLAME AWAY FROM SERVICE VALVE PREPARATION FOR NEXT STEP 7 WRAP SERVICE VALVES To help protect service valve seals during brazing wrap water saturated clo...

Page 8: ...TION EQUALIZER LINE INSTALLATION A Remove and discard either the flare seal cap or flare nut with copper flare seal bonnet from the equalizer line port on the suc tion line as illustrated in the figur...

Page 9: ...door unit E After 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 F After leak testing disconnect gauge...

Page 10: ...utting off the vacuum pump and closing the manifold gauge valves F When the absolute pressure requirement above has been met disconnect the manifold hose from the vacuum pump and connect it to a cylin...

Page 11: ...re only with this product CAUTION Failure to use properly sized wiring and circuit breaker may result in property damage Size wiring and circuit breaker s per Product Specifications bulletin EHB and u...

Page 12: ...t and secure with provided wire tie B Make 24VAC thermostat wire connections Locate the two wires from the contactor and make connection using field provided wire nuts Yellow to Y1 Black to C common R...

Page 13: ...ped with a service port which has a factory installed valve stem Figures 15 and 16 provide information on how to access and operate both angle and ball type service valves Torque Requirements When ser...

Page 14: ...he tables provided on the charging procedure sticker located on the unit access panel Detailed information is provided in the 14ACX Installation and Service Procedures manual Corp0638 L10 which is ava...

Page 15: ...as necessary 6 Inspect contactor contacts for pitting or burn marks Replace as necessary 7 Check outdoor fan motor for worn bearings bushings Replace as necessary 8 Inspect and clean outdoor coils if...

Page 16: ...re Supply Air Temperature Ambient Temperature Return Air Temperature System Refrigerant Charge Refer to manufacturer s information on unit or installation instructions for required subcooling and appr...

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