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Greenheck Packaged DX Module (474681) User Manual

Page 9

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9

Packaged DX Module for Make-Up Air Unit

SPECIAL TOOLS REQUIRED

• Voltage Meter (with wire probes)
• Amperage Meter
• Pressure Gauges – (refrigerant)
• Tachometer
• Thermometer
• Incline manometer or equivalent

Start- Up Procedure

The unit will be in operational mode during start-up. Use
necessary precautions to avoid injury. All data must be
collected while the unit is running.
o

Make sure Pre-Start-Up checklist is complete.

o

Jumper R to G, R to Y1, and R to Y2 (if applicable)

on the control board.

o

Turn the disconnect on. After 3 minutes

compressors will come on. Make sure all fans and
compressors are rotating the correct direction.

o

Allow the unit to run until the refrigerant system

stabilizes. Approximately 5-10 minutes.

Voltage Imbalance

In a 3-phase system, excessive voltage imbalance
between phases will cause motors to overheat and
eventually fail. Maximum allowable imbalance is 2%.
To determine voltage imbalance, use recorded voltage
measurements in this formula.
Key:

V1, V2, V3 = line voltages as measured

VA (average) = (V1 + V2 + V3) / 3

VD = Line voltage (V1, V2 or V3) that

deviates farthest from average (VA)

Formula:

% Voltage Imbalance = [100 x (VA-VD)] /VA

Pre-Start-Up Checklist

o

Disconnect and lock-out all power switches.

o

Remove any foreign objects that are located in the

unit.

o

Check all fasteners, set-screws, and locking collars

on the fans, bearings, drives, motor bases and
accessories for tightness.

o

Rotate the fan wheels by hand and ensure no parts

are rubbing.

o

Filters can load up with dirt during building

construction. Replace any dirty pleated filters and
clean the aluminum mesh filters in the intake hood.

o

Verify that non-motorized dampers open and close

properly.

o

Check the tightness of all factory wiring

connections.

o

Verify control wire gauge.

o

Verify proper drain trap installation.

o

Check condensing fans for any damage or

misalignment. Spin the blades and make sure they
don’t contact any parts and are free turning without
any resistance.

o

Look over the piping system.

o

Inspect all coils within the unit. Fins may get

damaged in transit or during construction. Carefully
straighten fins with a fin comb.

o

If there is an indirect gas-fired furnace in this unit,

refer to the manual provided with this unit for Pre-
Start-Up information.

o

This unit contains a crankcase heater for each

compressor which needs power supplied to it
24 hours prior to start-up. If start-up is scheduled in
24 hours, unlock the disconnect power and energize
unit.

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