15
Compressor Preheating Function
The compressor crankcase heater will activate if:
— The outdoor ambient temperature, T4, is lower than 37
_
F
(3
_
C) and power has been recently supplied to the machine.
— If T4 < 37
_
F (3
_
C) and the compressor has not been
operating for over 3 hours.
During the preheating mode, a weak current flow flows through
the compressor coil from the wiring terminal of the compressor.
The compressor is heated when this is not operating.
The preheating function will deactivate if T4 is greater than 41
_
F
(5
_
C) or the compressor starts operating.
Condenser temperature protection
The condenser temperature protection function acts as follows:
— If the condenser coil temperature (T3) is between 131
_
F
and 140
_
F (55C
_
<T3<60
_
C), the compressor frequency
will decrease to a lower level until it reaches the lowest
value, F1. It then runs at this F1 frequency. Once
T3<129
_
F (54
_
C), the compressor will continue running
at the current frequency.
— When the coil temperature reaches a value lower than
126
_
F (52
_
C), the compressor will not limit the
frequency and resumes to the required frequency.
— If T3>140
_
F (60
_
C) for 5 seconds, the compressor will
stop and restart once the coil temperature reaches a value
lower than 126
_
F (52
_
C).
Evaporator Temperature Protection
The evaporator temperature protection function acts as follows:
— If the evaporator coil temperature (T2) is lower than
32
_
F (0
_
C), the compressor will stop and restarts once
T2
≥
41
_
F (5
_
C).
— If 32
_
F
≤
T2 <39
_
F (0
_
C
≤
T2 <4
_
C), the compressor
frequency will be limited and decreased to a lower level.
— Now, if 39
_
F
≤
T2 <45
_
F (4
_
C
≤
T2 <7
_
C), the
compressor continue running at the current frequency.
— If T2>45
_
F (7
_
C), the compressor frequency will not be
limited, and operation is normal.
SEQUENCE OF OPERATION
Interface
A wireless remote control, supplied with the unit, is the interface
between the fan coil and the user. The wireless remote control has
the following characteristics:
S
Capable of displaying
_
C and
_
F with
_
F being the default
setting. To change the default setting, refer to the Owner’s
Manual.
S
The remote control setpoint range is from 62
_
F (17
_
C) to
86
_
F (30
_
C) in increments of 1
_
F (1
_
C).
S
The wireless remote control has an operating range of 25 ft.
(7.62 m).
S
The same remote control can be used to control more than one
unit.
S
If the remote control is lost, damaged, or the batteries are
exhausted, the system can be operated by using the manual
button (forced Auto) located under the front panel.
Manual Button
AUTO/COOL
Fig. 18 – Manual Button Location on Unit
MODES OF OPERATION
COOLING MODE
In this mode, the system cools and dries the room air with the fan
running continuously, either at a selected fan speed or Auto fan
speed. The fan runs even when the compressor cycles off. This
feature enhances room comfort and efficiency of the system.
Compressor operation in cooling mode:
In cooling mode, the maximum operation frequency (Fmax) of the
compressor, after it starts running, depends on the outdoor ambient
temperature (T4).
Once the system starts running, the compressor will run at the Fmax
frequency for 7 minutes at a specific T4. During this time, the
frequency limitation is active, therefore the compressor will continue
running even if the set point condition is satisfied. The compressor
running frequency will then be controlled based on the difference
between the room temperature and the temperature set point (T1- Ts).
Outdoor Fan Operation in Cooling Mode:
When in cooling mode, the outdoor fan motor cycles based on the
outdoor ambient temperature as shown below:
Fig. 19 – Cooling mode
Indoor Fan Operation in Cooling Mode:
When in cooling mode, the indoor fan runs continuously either at
the chosen set speed (high, medium, or low), or in Auto mode,
where the speed is determined by the microprocessor based on the
difference between the room temperature and the temperature set
point as shown below:
4
3
High
Low
1
Medium
1.5
Fig. 20 – Cooling mode
Summary of Contents for 38GRQB09-3
Page 10: ...10 Outdoor unit Fig 11 Sizes 09 12...
Page 46: ...46 EXPLODED VIEW AND PARTS LIST Indoor Unit Fig 47 Indoor Unit...
Page 48: ...48 OUTDOOR UNIT Fig 48 Outdoor Unit...
Page 50: ...50 Fig 49...
Page 53: ...53 Shut off power hold both ends of horizontal...
Page 54: ...54...
Page 55: ...55...
Page 56: ...56 ziptie side cutters...
Page 57: ...57...
Page 58: ...58...
Page 59: ...59...
Page 60: ...60...
Page 73: ...73 6 7 8...
Page 74: ...74 9 Remove electric box 10 Remove evaporator...
Page 75: ...75...
Page 76: ...76 11 Remove swing blade...
Page 77: ...77 12 Remove cross flow blade and motor...
Page 78: ...78 13 Remove drive box...
Page 90: ...90 APPENDIX Appendix 1 Reference Sheet of Celsius and Fahrenheit...
Page 95: ...95 UNIT BREAKDOWNS a b c d e...
Page 96: ...96 f g h...
Page 97: ...97...
Page 98: ...98...
Page 99: ...99...