Condition
Though a test operation (check operation) in combination with the VRV II series outdoor unit had completed, an malfunction “E4 (abnormal low pressure malfunction)” or an malfunction “F3 (abnormal discharge pipe temperature malfunction )” occurred frequently after that.
Cause
Due to erroneous connection of wires and pipes, electronic expansion valve of the indoor unit does not open when only a single system is operated, which causes a faulty refrigerant circulation and results in a drop of pressure for low-pressure. Normal pressure is obtained by operating two systems simultaneously.
Measure
Issue a slip of request for modification work so that the erroneous connection of wires and pipes is corrected.
Point of Diagnosis
If a test operation (check operation) of multiple units of VRV II series is executed simultaneously, the test operation ends normally even if an erroneous connection exists. Be sure to execute a test operation (check operation) on an individual unit.
Check whether there is an erroneous connection if an malfunction “E4” or an malfunction “F3” generates on the existing equipment.
