Si30-408
VRV in General
Cases for Examination
113
1.6
Cautions for Test Operation
Applicable
Models
RX(Y)(Q)
~
M (VRV II series)
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.
1.7
Cautions for Demand Control with Externally Controlled
Adapter
Applicable
Models
RX(Y)(Q) ~ M (VRV II series)
Condition
Demand control with an externally controll adapter attached to the VRV II series outdoor unit is
desired.
Thermostat does not turn off though C and 3 were short-circuited i.e., demand level 3, after
setting.
*
Set items: Demand address 1 (Setting mode 2-2)
Externally controll ADP address 1
Demand setting change to ON from OFF (Setting mode 2-12)
Cause
Demand level setting (setting mode 2-30) remained to be the factory set value i.e., "70%".
It should be changed the setting to "60%" to turn OFF the thermostat by the short circuit
between C and 3.
Measure
The thermostat turns OFF by changing the setting mode 2-30 to "60%".
Point of
Diagnosis
Change of mode setting is needed in accordance with the purpose of use.
For setting methods, refer to the page 56 "2. Field setting on outdoor unit", of the section "C.
Filed Settings from remote controller."