17
SYSTEM SAFETIES
3 Minute Time Delay
In order to protect the compressor, there is a 3 minute delay on
break even if the control is calling for heating or cooling. The
compressor will have an additional 1 minute delay when powering
the unit on for the first time, or after a power failure.
Compressor Top Temperature Protection
The unit will stop working when the compressor top temperature
protector cuts off, and will restart after the compressor top
temperature protector restarts.
Compressor Discharge Temperature Protection
When the compressor discharge temperature reaches a higher one
than in normal operation, the running frequency will be limited
based on the algorithm presented below:
— If the compressor discharge temperature is lower than
194
_
F (90
_
C), there is no limit in the frequency.
— If this value is between 194
_
F and 221
_
F
(90<T5<105
_
C), the compressor will continue running
at the current frequency.
— If this value is now between 221
_
F and 239
_
F
(105<T5<115
_
C), the frequency will decrease to a lower
level every 3 minutes.
— When the compressor discharge temperature reaches a
value higher than 239
_
F (115
_
C), and has been running
at this condition for 5 seconds, the compressor stops.
Fan Speed Protection
When the indoor fan speed has been too low (300RPM) for certain
time, the unit will stop and the LED will display the failure.
Inverter Module Protection
The Inverter module is protected for abnormalities in current,
voltage and temperature. If abnormal values of any of these take
place, the corresponding code will be displayed in the indoor unit
and the unit will stop.
Indoor Fan Delayed Operation
When the unit starts up, the louver will be active immediately and
the indoor fan will operate 10s later. If the operating mode is
heating, the indoor fan will also be controlled by the anti--cold
blow function.
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.
Zero Crossing Detection Error Protection
If the a detected zero crossing time interval is not correct for a
continuous 240 seconds, the unit will stop and the LED will
display the failure. The correct zero crossing signal time interval
should be between 6 to 13 minutes.
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
A14359
Fig. 16 – Manual Button Location on Unit
