Unitary products group EF-10, Инструкция по установке

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035-18550-001-A-0902
18 Unitary Products Group
remain cool for all cycles - the line between the
compressor and the accumulator and the line
between the accumulator and the reversing valve.
INITIAL START-UP
1. Supply power to the unit through the disconnect
switch prior to starting the compressor.
2. Move the system switch on the room thermostat to
the “COOL” position, and lower its set point to
energize both the compressor and the reversing
valve. Cool air will be supplied to the conditioned
space.
3. Check the compressor amperage. It should not
exceed the RLA rating printed on the unit data
plate or in Table 3 unless the ambient temperature
is above 105°F.
4. Move the system switch on the room thermostat to
the “HEAT” position, and increase the set point of
the room thermostat until heating is required. The
compressor will run, but the reversing valve will be
de-energized. Warm air will be supplied to the con-
ditioned space.
5. Check the operation of the indoor unit per Form
515.41-N2.
6. Check the entire system for refrigerant leaks.
7. Check for any abnormal noises and/or vibrations,
and make the necessary adjustments to correct
(e.g. fan blade touching shroud, refrigerant lines
hitting on sheet metal, etc.)
8. After the unit has been operating for several min-
utes, shut off the main power supply at the discon-
nect switch and inspect all factory wiring
connections and bolted surfaces for tightness.
PHASING
Scroll compressors operate in one direction only. If a
three phase scroll compressor is experiencing:
• Low amperage draw
• Similar discharge and suction pressures
• Increased noise level
then the compressor is operating in reverse. To correct
this condition, switch any two (2) line voltage leads at
the contactor. Please note, single phase scroll com-
pressors will start and run in one direction only. The
reverse operation is not a concern.
OPERATION
GENERAL
During the cooling cycle, when the reversing valve
solenoid becomes energized, operation will be the
same as any conventional air conditioning system.
During the heating cycle, when the reversing valve
solenoid becomes de-energized, compressor dis-
charge gas will be diverted to the indoor coil and the
outdoor coil will become the evaporator.
Refer to Figure 8 for illustration showing the flow of
refrigerant through a heat pump system.
SYSTEM SEQUENCE OF OPERATION
The following sequences of operation are based on
using the manual changeover thermostat. Refer to the
respective unit wiring diagram.
COOLING OPERATION
1. The following controls will be energized through
terminal O on the thermostat to put the system in
the cooling mode.
• Relay RW (460 volt units) and RVS (230 volt
units) and reversing valve solenoid.
2. If the fan switch on the thermostat is in the “ON”
position, indoor section blower motor contactor
10M will be energized through terminal G to
Units equipped with scroll compressors oper-
ate in one direction only.
Incorrect scroll compressor rotation can dam-
age or fail the compressor(s).
Reversing valves and check valves are precise
mechanical devices and will not tolerate any
mechanical abuse such as hammering. If a
refrigerant system isn't properly cleaned after a
compressor burn-out, scale may build up at
these devices and prevent them from operating
properly.