Cancels: II 548D-90-1 II 548D-90-2
10/15/00
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . 1
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-27
I. Step 1— Provide Unit Support . . . . . . . . . . . . . . . . . 1
II. Step 2 — Field Fabricate Ductwork . . . . . . . . . . . . . 3
III. Step 3 — Install Condensate Drain Line
and External Trap. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
IV. Step 4 — Rig and Place Unit. . . . . . . . . . . . . . . . . . . 3
V. Step 5 — Make Electrical Connections . . . . . . . . . . 7
VI. Step 6 — Adjust Factory-Installed Options. . . . . . 11
VII. Step 7 — Adjust Indoor-Fan Speed . . . . . . . . . . . . 19
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28-30
I. Unit Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
II. Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
III. Outdoor-Air Inlet Screen . . . . . . . . . . . . . . . . . . . . . 28
IV. Compressor Mounting. . . . . . . . . . . . . . . . . . . . . . . 28
V. Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
VI. Refrigerant Service Ports . . . . . . . . . . . . . . . . . . . . 28
VII. High Flow Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
VIII. Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . 28
IX. Adjust Gas Input . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
X. Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
XI. Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
XII. Safety Relief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
XIII. Ventilation (Continuous Fan) . . . . . . . . . . . . . . . . . 29
XIV. Operating Sequence . . . . . . . . . . . . . . . . . . . . . . . . 29
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30-33
I. Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
II. Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
III. Outdoor Fan Adjustment. . . . . . . . . . . . . . . . . . . . . 32
IV. Economizer Adjustment . . . . . . . . . . . . . . . . . . . . . 32
V. Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . 32
TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . .34-38
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . CL-1
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can
be hazardous due to system pressure and electrical com-
ponents. Only trained and qualified service personnel should
install, repair, or service air-conditioning equipment.
Untrained personnel can perform basic maintenance func-
tions of cleaning coils and filters and replacing filters. All
other operations should be performed by trained service per-
sonnel. When working on air-conditioning equipment, ob-
serve precautions in the literature, tags and labels attached
to the unit, and other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work gloves.
Use quenching cloth for unbrazing operations. Have fire ex-
tinguisher available for all brazing operations.
INSTALLATION
Unit is shipped in the vertical configuration. To convert to
horizontal configuration, remove side duct opening covers.
Using the same screws, install covers on vertical duct open-
ings with the insulation-side down. Seals around duct open-
ings must be tight.
I. STEP 1 — PROVIDE UNIT SUPPORT
A. Roof Curb
Assemble and install accessory roof curb in accordance with
instructions shipped with curb. See Fig. 1. Install insulation,
cant strips, roofing felt, and counter flashing as shown. Duct-
work must be attached to curb. If electric or control power is
to be routed through the basepan, attach the accessory thru-
the-bottom service connections to the basepan in accordance
with the accessory installation instructions. Connections
must be installed before unit is set on roof curb.
IMPORTANT: The gasketing of the unit to the roof curb is
critical for watertightness. Install gasket supplied with the
roof curb as shown in Fig. 1. Improperly applied gasket can
also result in air leaks and poor unit performance.
Curb should be level. Unit leveling tolerances are shown in
Fig. 2. This is necessary for unit drain to function properly.
Refer to Accessory Roof Curb Installation Instructions for
additional information as required.
B. Slab Mount (Horizontal Units Only)
Provide a level concrete slab that extends a minimum of 6 in.
beyond unit cabinet. Install a 6 in. gravel apron in front of
condenser coil air inlet to prevent grass and foliage from
obstructing airflow.
NOTE: Horizontal units may be installed on a roof curb if
required.
WARNING: Before performing service or mainte-
nance operations on unit, turn off main power switch
to unit and tag disconnect with lockout tag. Electrical
shock could cause personal injury.
CAUTION: Ensure voltage listed on unit data
plate agrees with electrical supply provided for the
unit.
installation, start-up and
service instructions
SINGLE PACKAGE ROOFTOP
STANDARD-EFFICIENCY HEAT PUMP UNITS
548D
Sizes 090-120
7
1
/
2
to 10 Tons
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