Bosch IDS BOVA15 Installation Instructions Manual page 35

WARNING: HAZARDOUS VOLTAGE

When measuring resistance , make sure the unit is powered
off and wait 3 min before taking measurement.
PH (Low discharge superheat protection)
Are
you running in force
mode?
No
Are the service valves
open?
Yes
Is there abnormal
pressure in the
system?
No
Is the system
undercharged?
No
Is the
EEV/TXV working
normally?
No
Is the
resistance of T5
in range of Table
16?
Yes
Is the
resistance of T3
in range of Table
15?
Yes
Restart System
Figure 57
Bosch IDS BOVA15 Split System Heat Pump - BTC 761701317 A (02.2022)
Is the
Yes ambient temperature
>120°F?
No
Quit force mode
Open the service valves
No
Clear any blockage in the
refrigerant,Correct poor
Yes
heat exchange (air flow
restriction, motor failure)
Yes Adjust refrigerant
Yes Adjust or replace EEV/TXV
Replace T5 sensor
No
Replace T3 sensor
No
Are the service valves
open?
Yes
Is the power
supply stable?
Yes
Yes
Check
for blockage in EEV,
TXV or Filter Drier
No
Is
there any
abnormal noise from
the compressor?
No
Power off and wait 3 minutes
before powering on
Does the
unit run normally for
at least 1 hour?
No
Check
the winding resistance:
1.The resistance of two windings (U,V,W)
<1.5Ω for 2/3T and <1Ω for 4/5T
2.The resistance between compressor
winding and ground
>10MΩ
No
Is the
compressor current >11.5A
for 2/3T and >15.5A for
4/5T?
Yes
Replace control board
Figure 58
Installation Instructions
L0-L9 (IPM module protection)
No
service valves
Correct the
No
power supply
Yes
Remove blockage
Yes
compressor
Yes
refrigerant charge
No
compressor
No
compressor
Open the
Replace
Check the
Replace
Replace
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