Electronic Functions; Abbreviation; Main Protection - Bosch Climate 5000 Series Service Manual

Service Manual

7 Electronic Functions

7.1 Abbreviation

T1: Indoor room temperature
T2: Coil temperature of evaporator
T3: Coil temperature of condenser
T4: Outdoor ambient temperature
T5: Compressor discharge temperature
Ts: Room temperature setting
Td: Off-set value (Td is an advanced feature)
T2b-A: Suction temp for zone A in cooling (discharge temp for each zone in heating)
T2b-B: Suction temp for zone B in cooling (discharge temp for each zone in heating)
T2b-C: Suction temp for zone C in cooling (discharge temp for each zone in heating)
T2b-D: Suction temp for zone D in cooling (discharge temp for each zone in heating)
T2b-E: Suction temp for zone E in cooling (discharge temp for each zone in heating)

7.2 Main Protection

7.2.1 Three minutes delay at restart for compressor
1 minute delay for the 1st time start-up and 3 minutes delay for others.
7.2.2 Temperature protection of compressor discharge
When the discharge temperature of the compressor rises, the operation frequency
is limited according to the following rules:
If 105 °C (221 °F) T5 < 110 °C (230 °F), maintain the current
frequency.
If the temperature increases and T5 110 °C (230 °F), decrease the
frequency to a lower level every 2 minutes to F1.
If T5 115 °C (239 °F) for 10 seconds, the compressor stops and then
restart until T5 < 90 °C (194 °F).
7.2.3 Fan speed is out of control
If outdoor fan speed is lower than 100RPM or higher than 2400RPM for 60
seconds or more, the unit stops and LED displays E8 failure code.
7.2.4 Inverter module protection
The Inverter module has a protection function for current, voltage and temperature.
If these protections happen, the corresponding code will display on the indoor
unit and the unit will stop working. The unit restarts 3 minutes after the protection
mechanism has turned off.
7.2.5 Low voltage protection
If low voltage protection triggers and voltage is not restored to normal within 3
minutes, the protection remains active even after a machine restart.
Bosch Thermotechnology Corp. | 08.2020
Bosch Climate 5000 Series Ductless Air Conditioner / Heat Pump Multi Zone Outdoor Units | 15
7.2.6 Compressor current limit protection
The temperature interval for the current limit is the same as the range of the T4
frequency limit.
Cooling mode:
CoolReturnI
CoolT4Zone5I
CoolT4Zone4I
CoolT4Zone3l
CoolT4Zone2l
CoolT4Zone1l
CoolStopI
Figure 11
Heating mode:
HeatReturnI
HeatT4Zone4I
HeatT4Zone3I
HeatT4Zone2l
HeatT4Zone1l
HeatStopl
Figure 12
50
49
45
44
41
40
33
32
The difference between current limit and shutdown current
Cooling T4 50 current limit value
Cooling 49 T4 45 current limit value
Cooling 44 T4 41 current limit value
Cooling 40 T4 33 current limit value
Cooling 32 T4 current limit value
Cooling stop protection current value
The difference between current limit and shutdown current
Heating T4 15 current limit value
Heating 14 T4 10 current limit value
Heating 9 T4 6 current limit value
Heating 5 T4 current limit value
Heating stop protection current
Data subject to change