Diagnose the trouble correctly before
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Communication format
Note: This communication format is compatible with 3 models, i.e., double-compressor one-drive-two without converter, single-compressor one-drive-two without converter and one-drive-two with converter.
2.1. Sequence of communication
Communication begins 2 seconds after the power supply inputs. The indoor unit first gives out a signal and outputs the LO which remains at 5 ms, then changes to receive signal. If it fails to receive signal 2 seconds after the signal is given out, it will give out a signal once again. After the signal is received, it will give out a signal once more 10 ms later. When the indoor unit is waiting for the signal input, the signal output is HI. If the indoor unit fails to receive signals in normal condition in times (20 seconds) after the previous signal has been received, the transmission is abnormal. But time shortage and being halted are not of abnormal transmission. Communication is carried out when a correct HDA signal is received. After the signal has been received, the communication data is compared with the inverter data. When incorrect, all the data will be given up. The outdoor unit waits to receive signal HEADER HDR(81H) from the indoor unit after the power supply inputs. After the signal has been received, the communication data is compared with the inverter data. When incorrect, all the data will be given up.
The outdoor unit waits to receive signal HEADER HDR(81H) from the indoor unit after the power supply inputs. When transmitting signal, HEADER is C3H. When a signal is first transmitted at the head, data "1" outputs HI of 9MS and LO of 2MS and data "0" outputs HI of 2MS and LO of 9MS.
When receiving signal, the signal reception is carried out depending on the majority of the 5th, 6th and 7th 5,6,7MS.
The signal reception will not take place until a correct HDR signal is received
Checkout of errors
The signal reception does not take place until the outdoor unit receive signal HDR from the indoor unit. At the completion of the signal reception, the data is compared with the inverter data. When incorrect, all the data is given up. If it is incorrect in 20 seconds of comparison, the compressor, 4-way valve and outdoor fan turn off, giving the abnormal condition and sending out the corresponding error codes for the abnormalcy of signal delivery and transmission.
2.3. Timer for communication data input /output
After the power supply inputs, the outdoor communication output is HI, waiting for the indoor unit to send signal.
The timer counter is cleared 0 at the decline of communication, regarding 3 times of 5,6,7 ms.
The status of the communication input PORT determines input signals. When in the next decline of communication, the timer counter is cleared one again.
HEADER 8 bits, the data and inverter data 48 bits, and the total is 56 bits. After the data has been received, LO of 10 ms is ready to send signal. The 0 clearance of the timer counter during the sending takes place in a 1 ms interruption.
HEADER 8 bits, the data and inverter data 48 bits, and the total is 56 bits. After the data has been sent, Both output LO of 5 ms and output HI of 5ms are ready to receive signal 4 and communications
Single-unit cooling operation
3.1. When the single unit’s indoor unit gives a cooling signal, the corresponding outdoor compressor carries out cooling operation. During the operation, the outdoor fan operates 1 second before the compressor operates.
3.2. When changed from heating to cooling, the compressor stands by for 3 minutes, the outdoor fan operates to blow off remaining heat and stops 30 seconds later.
3.3. When the outdoor ambient temperature T1≥38℃, the outdoor fan runs at the high speed.
There is a return difference of 2℃ for the change between high and medium speed.
When the outdoor ambient temperature T1≤26℃, the outdoor fan runs at the low speed. There is a return difference of 2℃ for the change between low and medium speed.
When the outdoor ambient temperature T1≤8℃, the outdoor fan is in a cycle of 1 minute stop and 3 minute run. There is a return difference of 2℃ for the change between low speed and run and stop.
3.4. Once the fan operates in a mode, it must operate for more than 45 seconds.
There is a temperature cut-off protection: when the indoor coil temperature higher than T_CPS (68 ℃) and maintains for 10 seconds, both the compressor and outdoor fan stop. The compressor will not restart in 3 minutes until the coil temperature lower than T_CP R(50℃). The indoor fan is controlled the same as the thermostat is OFF.
4. Double-unit cooling operation
4.1. When the indoor unit gives out a double unit cooling signal, outdoor compressor A starts cooling operation. During the operation, the outdoor fan runs 1 second before compressor A operates, 20 seconds later, outdoor compressor B starts cooling operation.
4.2. Once a compressor starts, the other compressor will not start in 20 seconds from the start.
4.3. When changed from heating to cooling, the compressor stands by for 3 minutes. When both compressors are in the strand-by status, the outdoor fan stops. Otherwise, it operates. The status of the fan depends on the number of the compressors that operate.
4.4. When the outdoor ambient temperature T1≥30℃, the outdoor fan runs at the high speed.
There is a return difference for the change between high and medium speed;
When the outdoor ambient temperature T1≤23℃, the outdoor fan runs at the low speed. There is a return difference for the change between low and medium speed;
When the outdoor ambient temperature T1≤5℃, the outdoor fan is in a cycle of 1 minute stop and 3 minute run. There is a return difference of 2℃ for the change between low speed and run and stop.
4.5. Once the fan operates in a mode, it must operate for more than 45 seconds.
4.6. There is a temperature cut-off protection: when a indoor coil temperature higher than T_CPS (68℃) and maintains for 10 seconds, the corresponding compressor stops. The compressor will not restart in 3 minutes until the coil temperature lower than T_CP R(50℃). The indoor fan is controlled the same as the thermostat is OFF.
4.7. In the case of double-unit cooling, one compressor stops and it changes to the single-unit operation. The fan is controlled in the single-unit operation mode. It stops 30 after blowing off the remaining heat only if both compressors turn off at the same time.
5. Single unit heating operation:
5.1. When the single unit’s indoor unit gives a heating signal, the corresponding outdoor compressor carries out cooling operation. During the operation, the outdoor fan and 4-way valve operate 1 second before the outdoor fan operates.
5.2. When changed from cooling to heating, the compressor stands by for 3 minutes, the outdoor fan stops.
5.3. When the outdoor ambient temperature T1≤3℃, the outdoor fan runs at the high speed. There is a return difference of 2℃ for the change between high and medium speed.
When the outdoor ambient temperature T1≥13℃, the outdoor fan runs at the low speed. There is a return difference of 2℃ for the change between low and medium speed.
5.4. Once the fan operates in a mode, it must operate for more than 45 seconds.
5.5. There is a high temperature protection and a temperature cut-off protection.
High temperature protection: When the indoor coil temperature higher than T_OFS (56℃), the outdoor fan stops; when the coil temperature falls to T_OFR (52℃), the outdoor fan restarts. The outdoor fan stops for more than 45 seconds.
High temperature cut-off protection: When the indoor coil temperature higher than T_CPS (68℃) and maintains for 10 seconds, both the compressor and outdoor fan stop, and the indoor fan operates as the thermostat is Off. The compressor will not restart in 3 minutes until the coil temperature lower than T_CP R(50℃).
6. Double-unit heating operation
6.1. When the double-unit’s indoor unit gives out a heating signal, outdoor compressor A starts heating operation. During the operation, outdoor compressor A and the 4-way valve operate 1 second before the fan starts, 20 seconds later, outdoor compressor B starts heating operation.
6.2. Once an outdoor compressor starts, the other compressor will not start in 20 seconds from the start.
6.3. When changed from cooling to heating, the compressor stands by for 3 minutes. When both compressors are in the strand-by status, the outdoor fan stops. Otherwise, it operates. The status of the fan depends on the number of the compressors that operate.
6.4. When the outdoor ambient temperature T1≤10℃, the outdoor fan runs at the high speed.
There is a return difference for the change between high and medium speed;
When the outdoor ambient temperature T1≥20℃, the outdoor fan runs at the low speed. There is a return difference for the change between low and medium speed.
6.5. Once a fan operates in a mode, it must operate for more than 45 seconds.
7. Cooling and heating operations take place at the same time:
7.1. When one of the indoor units gives out a cooling signal and another unit gives out a heating signal at the same time, the outdoor fan operates at the low speed.
7.2. When the indoor unit gives the value of coil temperature, the outdoor fan runs at the low speed if the heating outdoor unit judges high load.
7.3. When outdoor ambient temperature T1≥28℃, there is no heating operation.
7.4. When outdoor ambient temperature T1≤7℃, there is no cooling operation.
7.5. Once a compressor starts, the other compressor will not start in 20 seconds from the start.
8. Single-unit heating operation with heat load:
8.1. In the single-unit heating operation, the indoor unit gives out the value of the coil temperature, and the outdoor unit judges whether to start in the high load protection operation based on the value of the coil temperature it has received. If the conditions for high load protection are met, the outdoor fan stops immediately. It will restart 45 seconds later if the signal for the outdoor heat load disappears. Otherwise, the outdoor fan will continue to stop until the signal for the outdoor heat load disappears. The signal for heat load is as follows:
High temperature protection: When the indoor coil temperature higher than T_OFS (56℃), the outdoor fan stops; when the coil temperature falls to T_OFR (52℃), the outdoor fan restarts. The outdoor fan stops for more than 45 seconds.
High temperature cut-off protection: When the coil temperature higher than T_CPS (68℃) and maintains for 10 seconds, both the compressor and outdoor fan stop, and the indoor fan operates as the thermostat is Off. The compressor will not restart in 3 minutes until the coil temperature lower than T_CP R(50℃).
8.2. In the single-unit heating operation, the current in the compressor is larger than 5.8A, and the outdoor fan stops. 45 seconds later, the current in the compressor is less than 5.3A, and the outdoor fan operates in normal condition(the compressor does not detect current within 30 seconds after its start), the current in the compressor is larger than 5.3Aand less than 5.8A, and the outdoor fan does not restore.
9. Double-unit heating operation with heat load
9.1. In the double-unit heating operation, the indoor unit gives out the value of the coil temperature, and the outdoor unit judges whether to start in the high load protection operation based on the value of the temperature it has received. If the conditions for high load protection are met, the outdoor fan stops immediately. It will restart 45 seconds later if the signal for the outdoor heat load disappears. Otherwise, the outdoor fan will continue to stop until the signal for the outdoor heat load disappears. The signal for heat load is as follows:
High temperature protection: When the indoor coil temperature higher than T_OFS (56℃), the outdoor fan stops; when the coil temperature falls to T_OFR (52℃), the outdoor fan restarts. The outdoor fan stops for more than 45 seconds.
High temperature cut-off protection: When the coil temperature higher than T_CPS (68℃) and maintains for 10 seconds, both the compressor and outdoor fan stop, and the indoor fan operates as the thermostat is Off. The compressor will not restart in 3 minutes until the coil temperature lower than T_CP R(50℃).
9.2. When the outdoor single-unit gives out the heat load signal, the outdoor fan stops immediately, 45 minutes later, the heat load signal disappears, and the outdoor fan operates.
9.3. In heating operation, any of the current in the compressor is larger than or equal to 5.8A , and the outdoor fan stops. The current in the compressor is less than or equal to 5.3A, and the outdoor fan restores (the compressor does not detect current within 30 seconds after its start), the current in the compressor is larger than 5.3A and less than 5.8A, and the outdoor fan does not restore
Current peak protection
The current in the compressor is larger than 10 Afro more than 5 seconds, The compressor which has the highest current will stop(the compressor does not detect current within 10 seconds after its start) and 3 minutes later it will continue to operate.
10.2. The compressor will no longer operate if overcurrent protection occurs 4 times in a row within 30 minutes, and the output transformer signal fails. In the double-unit operation, if one of the compressors stops due to the current too high, the other system is a single system.
11. Single-unit defrosting operation (outdoor judgement)
Defrosting control
11.1. Conditions for starting in the defrosting operation
The heating compressor starts and operate continuously for 10 minutes. After the compressor has been operating for 45 minutes in total (the defrosting operation ends, or when starting in the cooling mode, the compressor totals the operating time for zero clearance), detecting the defrosting sensor TE (detecting the frosting of the outdoor heat exchanger) and the outdoor ambient temperature sensor TA for straight 2 minutes, provided the following conditions are met, it will start for the defrosting operation: TE≤C×TA－α
Where,
C: TA＜0℃
C=0.8
TA≥0℃
C=0.6
αcan be selected according to the data of EEPROM
In the place where it tends to frost, it is preferred to choose H. In the place where it does not intend to frost, it is preferred to choose L. It is set M at delivery.
During the defrosting operation, the temperature control starts -15℃≤C×TA－α≤-2℃
Note: If the result of the calculation from C×TA－α is less than -15℃, -15℃ applies. If the result of the calculation from C×TA－α is larger than -2℃, -2℃ applies.
11.2. Interval of defrosting
When the result of the calculation from C×TA－α falls in the range of -15℃≤C×TA－α, the interval between two defrosting operations is 45 minutes.
When the result of the calculation from C×TA－α falls in the range of C×TA－α<-15℃, the interval between two defrosting operations is 55 minutes.
11.3. Defrosting operation
At the beginning of defrosting, the compressor is halted for the first one minute, but the outdoor fan operates, 50 seconds later, the 4-way valve is OFF.
During the defrosting operation, such protections as the compressor’s current protection are available.
The compressor may be interrupted for its protection or due to a trouble, and restore after 3 minutes. If it remains in the defrosting period, it will still start to defrost. The start of the compressor is made by the rules for the start of the defrosting compressor. (if it cannot restore 3 times in a row, it will be dealt with as in trouble and cancel defrosting.)
11.4. Once starting to defrost, the compressor must be guaranteed at least 2 minutes of operation before canceling defrosting. As for the conditions to cancel defrosting, it will restore to the heating operation from the defrosting operation as long as any of the following conditions is met.
(1) . The outdoor heat exchanger temperature is above 7 degrees for consecutive 80 seconds.
(2) . The outdoor heat exchanger temperature is above 5 degrees for consecutive 12 seconds.
(3) . The defrosting operation has lasted 9 minutes.
11.5. After the conditions for cancellation of defrosting are met, the following operations will follow:
The compressor stops, the outdoor fan starts, 50 seconds later, the 4-way valve is engaged, and 60 seconds later, the compressor operates.
12. Double-unit defrosting operation (outdoor judgement)
After receiving the signal to stop the indoor unit during the defrosting period, the unit must not be turned off until the outdoor defrosting lasts more than 2 minutes.
When the double units are activated for defrosting, the activation of compressor B is 20 minutes later than that of compressor A.
Conditions for ending defrosting: It will restore to the heating operation from the defrosting operation as long as any of the following conditions is met.
(1) . The temperatures on both outdoor heat exchangers are above 7 degrees for consecutive 80 seconds.
(2) . The temperatures on both outdoor heat exchangers are above 5 degrees for consecutive 12 seconds.
(3) . The defrosting operation has lasted 9 minutes.
The starting conditions and control process for the double-unit are same as that for single-unit defrosting, the only difference is that the activation of compressor B lags that of compressor A.
13. Alarming operation
1. When the whole unit is in normal operation, the alarm light is always on, but does not flash.
2. When the outdoor temperature sensor short-circuited or disconnected, the outdoor fan always operates at the medium speed and will restore automatically after the sensor comes to normal.
3. When the temperature sensors on the pipes A and B short-circuited or disconnected, the double unit will not carry out defrosting operation. During heating, this signal is sent to the indoor unit, but no sending for other operating conditions. When sent to the indoor unit, the whole unit stops.
The signal is sent to the indoor unit which coil is operating abnormally, and the corresponding indoor unit indicates trouble.
4. When the temperature sensor short-circuited or disconnected or the current transformer fails, the alarm light flashes in the following manner; when the current transformer fails, the signal is sent to the indoor unit that operates abnormally, and the corresponding indoor unit indicates trouble:
Faults
Schematic and wiring diagrams.
