Si30-408
Check Items before Troubleshooting
Troubleshooting
71
2.3
Check for Malfunction in Heating Operation
When heating malfunctions, check on the following factors to specify the state of malfunction
(peculiar on site). (In order to avoid an insufficient investigation at the initial check)
<At the time of normal operation, starting-up, before and after oil return operation, before
and after defrosting>
Make sure that the timing of heating malfunction generation.
If EV opening of all indoor units are the same degree, the instruction (control) for valve opening
degree is sent from the outdoor unit.
Make sure to grasp the state by using the checker.
Cold area, Snowfall area
Hot area, urban area
· Excessively frequent defrosting operation
· Operation standby due to outdoor temperature
· Refrigerant depositing in the indoor unit not in operation
· Rising of high pressure due to excess refrigerant
Open type shops, offices etc.
· Heating overload (high pressure
stepping
down) control
· Excessively frequent defrosting operation (fan control)
Excessively light load, short circuit in indoor unit,
erroneous selection of model
Excessively heavy load,
erroneous selection of model
Large pressure loss
· For operation with the target evaporating temperature
or lower (Unbalance between load and control)
Low
High
Low
High
Small
Large
Small
Large
Outdoor temperature
Indoor temperature
Indoor unit operation capacity, EV opening degree
Piping length, difference in vertical level
· Height difference in
installation level of indoor units
· Height difference between
outdoor unit and indoor unit
