Viessmann VITOCAL 250-A - Page 170

170
Measures
1. Check all cables connected to inverter:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
Replace cable if necessary.
2. Isolate the outdoor unit from the power supply. Wait
at least 2 min. Switch on voltage again.
3. Replace inverter.
F.1186 Offset error, inverter current sensor
F.1186
System characteristics
■
Output demand to heat pump not possible
■
Compressor not available
Cause
Internal inverter fault
Measures
1. Isolate the outdoor unit from the power supply. Wait
at least 2 min. Switch on voltage again.
2. Replace inverter.
F.1187 Fault, inverter current sensor outside the valid range
F.1187
System characteristics
■
Output demand to heat pump not possible
■
Compressor not available
Cause
Current value of the inverter is outside the permissible
measuring range.
Measures
1. Isolate the outdoor unit from the power supply. Wait
at least 2 min. Switch on voltage again.
2. Check connections U, V, W on the inverter:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
Replace cable if necessary.
3. Check connections X12 to X14 on the compressor
for short circuit with the cable disconnected.
Replace compressor if required.
4. Replace inverter.
F.1191 Fault, sensor interlock input 1
F.1191
System characteristics
■
Output demand to heat pump not possible
■
Compressor not available
Cause
■
Internal fault in inverter safety circuit
■
Faulty connection at input for inverter safety circuit
■
External protection equipment has responded, e.g.
RCDs, lightning protection, etc.
Messages
Fault messages (cont.)
6218234
Diagnosis