Service Manual

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3-WAY VRF SYSTEM
Control Functions
10. Indoor Unit Control of the Electronic Control Valve
10-1. Normal Control
(1) Cooling operation
Position of electronic control valve
Outdoor unit operating
Outdoor unit
stopped
Stopped 20 20
Fan 20 20
Cooling
Thermostat
OFF
20 20
Thermostat
ON
Performs SH control in the range of 55 – 480
pulses.
–
* The SH target value is controlled so that the difference [E3 – E1] is 4 – 12°F, depending on the operating conditions.
However, a decline in the required level may cause the SH target value to increase. Be aware that in this case, the
electronic control valve closes slightly. This can be easily identified incorrectly as insufficient gas.
(2) Heating operation
(A) Except Type E1
Position of electronic control valve
Outdoor unit operating
Outdoor unit
stopped
Stopped Shuts off refrigerant at 20 pulses. 85
Fan Shuts off refrigerant at 20 pulses. 85
Heating
Thermostat
OFF
Shuts off refrigerant at 20 pulses. 85
Thermostat
ON
Performs SC distribution control within the range of 55 –
480 pulses.
–
* The SC target value is controlled so that the difference [Pressure temp. sensor – E1] is 10 – 40°F, depending
on the operating conditions.
(B) Type E1
Position of electronic control valve
Outdoor unit operating
Outdoor unit
stopped
Stopped 20 20
Fan 20 20
Heating
Thermostat
OFF
20 20
Thermostat
ON
Performs SC distribution control within the range of 55 –
480 pulses.
–
* The SC target value is controlled so that the difference [Pressure temp. sensor – E1] is 10 – 40°F, depending
on the operating conditions.
However, if installation is combined with except type E1, the value is controlled so that the difference
[Pressure temp. sensor – E1] is 10 – 80°F.
SM830201-00_3WAY VRF.indb 23SM830201-00_3WAY VRF.indb 23 2012/01/30 14:58:462012/01/30 14:58:46