Installation guide

Referto the Product Data for recommended fuse sizes. When
making electrical connections, provide clearance at the unit for
refrigerant piping connections.
NOTE: The 38HDR units use the control transformer supplied
with the matched indoor unit.
Power Wiring
Unit is factory wired for voltage shown on nameplate. Provide
adequate, fused disconnect switch within sight from unit, readily
accessible, but out of reach of children. Provision for locking the
switch open (oft) is advisable to prevent power from being turned
on while unit is being serviced.
Disconnect switch, fuses, and field wiring must comply with the
NEC and local code requirements. Use copper wire only between
the disconnect switch and unit. Use nfininmm 75 C wire for the
field power connection.
Route power wires through the opening in unit side panel and
connect in the unit control box as shown on the unit label diagram.
Unit must be grounded.
Connections to Duct Free Fan Coil Units
The 38HDR units are designed for easy match-up to 40QA duct free
fan coils. This unit provides 24 v power for the outdoor unit from the
fan coil. Connect the Y and C ternfinals of the indoor unit to the Y and
C ternfinals.
START-UP
Step 1 --Preliminary Checks
1. Check that all internal wiring connections are tight and that
all barriers, covers, and panels are in place.
2. Field electrical power source must agree with unit name-
plate rating.
3. All service valves must be open.
4. Belly-band crankcase heater must be tight on compressor
crankcase for those units with belly-band heaters.
Step 2 --Evacuate and Dehydrate
Field piping and fan coil must be evacuated and dehydrated
Step 3 --Charge System
Release charge into system by opening (backseating) liquid and
suction line service valves.
Step 4 --To Start Unit
Be sure that the field disconnect is closed. Set room thermostat
below ambient temperature. Operate unit for 15 nfinutes, then
check system refrigerant charge. See Refrigerant Charging section
of this document.
NOTE: When using in coniunction with 40QA fan coils, refer to
start-up instructions included with fan coil for correct start-up
procedures.
SERVICE
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal iniury
or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch nmst be in the OFF position.
There may be more than 1 disconnect switch. Lock out and
tag switch with a suitable warning label.
Outdoor Fan
A reinforced wire mount holds the outdoor fan assembly in
position. See Fig. 5 for proper mounting position.
I I [_ .......... _ FAN BLADE
-LL_.<d t
OUTSIDEEDGEOF OUTSIDE EDGE DIMENSIONFROM
FANDECK OF GRILLE OUTSIDETOP EDGE OF
BLADETO OUTSIDEEDGE
OF FAN DECK.SEETABLE
BELOW
38HDR Unit Size, in. (mm)
018,024 030,036 048,060
0.433 (11.00) 0 0
Fig. 5 - Condenser Fan Mounting Positions
A07401
High-Pressure Relief Valve
The high-pressure relief valve is located in the compressor. The
relief valve opens at a pressure differential of approximately 550 to
625 - 50 psig between suction (low side) and discharge (high side)
to allow pressure equalization.
Internal Current and Temperature Sensitive Overload
The control resets automatically when internal compressor motor
temperature drops to a safe level (overloads may require up to 45
nfinutes to reset). When an internal overload is suspected of being
open, check by using an ohmmeter or continuity tester.
Pump-down Procedure
The system may be pumped down in order to make repairs on the
low side without losing complete refrigerant charge.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never open system to atmosphere while it is under a
vacuum.
When system nmst be opened for service, recover refrigerant, break
vacuum with dry nitrogen before opening system.
1. Attach pressure gauge to suction service valve gauge port.
2. Frontseat the liquid/nfixed phase line valve.
3. Start unit and run until suction pressure reaches 20 psig.
4. Shut unit off and frontseat suction valve.
5. De-pressurize low side of unit and recover refrigerant fol-
lowing accepted practices.
High-Pressure Switch
The high-pressure switch, located on discharge line, protects
against high discharge pressures caused by such events as
overcharge, condenser-fan motor failure, system restriction, etc. It
opens on pressure rise at about 650 - 10 psig. If system pressures
go above this setting during abnormal conditions, the switch
opens.
PERSONAL INJURY HAZARD
Failure to follow this warning could result in personal
iniury or death.
DO NOT attempt to sinmlate these system abnormalities -
high pressures pose a serious safety hazard.
The high-pressure switch is checked with an ohmmeter. If system
pressure is below 625 psig switch shows continuity.