10
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
—
Leak Test
Field piping and fan coil must be leak tested by pressure method.
Use Puron
r
refrigerant at approximately 25 psig backed up with an
inert gas to a total pressure not to exceed 245 psig.
Step 3
—
Evacuate and Dehydrate
Field piping and fan coil must be evacuated and dehydrated.
Step 4
—
Charge System
Release charge into system by opening (backseating) liquid and
suction line service valves.
Step 5
—
To Start Unit
Be sure that the field disconnect is closed. Set room thermostat
below ambient temperature. Operate unit for 15 minutes, then
check system refrigerant charge. See Refrigerant Charging section
on page 12.
NOTE
: When using in conjunction with 40QA fan coils, refer to
start--up instructions included with fan coil for correct start--up
procedures.
SERVICE
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must 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. 7 for proper mounting position.
38HDR Unit Size, in. (mm)
018,024
030,036
048,060
0.433 (11.00)
0
0
A07401
Fig. 7
---
Condenser Fan Mounting Positions
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
minutes to reset). When an internal overload is suspected of being
open, check by using an ohmmeter or continuity tester.
Pumpdown Procedure
The system may be pumped down in order to make repairs on the
low side without losing complete refrigerant charge.
CAUTION
!
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 must be opened for service, recover refrigerant, break
vacuum with dry nitrogen before opening system.
1. Attach pressure gage to suction service valve gage port.
2. Frontseat the liquid/mixed 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.
38H
D
R
