Outdoor Unit Ccu (Command Controller Unit) Control - Panasonic U-120ME2U9 Service Manual

6. Outdoor Unit CCU (command controller unit) Control

6. Outdoor Unit CCU (command controller unit) Control

Some actuators of indoor unit are controlled by CCU.
(1) MOV of Indoor Unit
1-1. Indoor unit without RAP valve kit
Operating
mode of
indoor unit
Stop
1
Fan (only)
2
Cooling
Heating
3
*1 SH control adjusts the difference between the liquid temperature and gas temperature in indoor unit.
SH = gas temperature (E3) - liquid temperature (E1)
4
Target SH is 37.4deg F (3deg C) when the load level of indoor unit is "30" or "31 (test run)".
Target SH will be increased up to 63.5deg F (17.5deg C) when the load level of indoor unit is low.
When the refrigerant amount in the system is adjusted, it is necessary to select test run mode that the
required level becomes "31".
*2 MOV pulse changes to 55 for 1 minute when the MOV pulse continues to be 55 or more for 10 minutes.
5
The purpose of this control is to decrease the flow volume of the refrigerant so that room temperature can be
detected with less influence of heat from the refrigerant.
*3 SC control adjusts the difference in temperature between the liquid temperature in indoor unit and
high-pressure saturated temperature in outdoor unit.
6
SC = high-pressure sensor temperature (HPS) - liquid temperature (E1)
Target SC is 9deg F ~ 27deg F (5deg C ~ 15deg C) according to the operating condition.
7
8
9
Operating Operating
mode of mode of
outdoor unit compressor
Stop
Cooling
Operation
Stop
Heating
Operation
Stop
Cooling
Operation
Stop
Heating
Operation
Stop
Cooling
Operation
Stop
Heating
Operation
Thermostat
ON/OFF
20
20
85
65 ~ 80
20
20
85
65 ~ 80
20
OFF 20
ON 60 ~ 480 (SH control*
85
55 ~ 80 (prevent remaining refrigerant,
OFF
suction temperature control*
ON 65 - 480 pulses (SC control*
1 - 22
2WAY VRF SYSTEM
2WAY VRF SYSTEM
Control Functions
Control Functions
MOV pulse of indoor unit
)
1
)
2
)
3
unit : pulse