Daikin VRV RXYMQ-A Series, Руководство по обслуживанию

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SiME332106E Special Control
Part 4 Functions and Control 67
7.3 Defrost Control
To defrost the outdoor heat exchanger while in evaporator, the defrost control is conducted to
recover the heating capacity.
Tc : High pressure equivalent saturation temperature
Te : Low pressure equivalent saturation temperature
 Defrost control is not conducted before 40 minutes have elapsed from the start of heating
operation.
 After 40 minutes have elapsed, defrost control starts when the following items meet the
reference values.
 Heat transfer coefficient of the outdoor heat exchanger
(The heat transfer coefficient of the outdoor heat exchanger is computed from Tc, Te,
and compressor loads.)
 Outdoor heat exchanger deicer temperature (Tb)
 Defrost control starts every 2 hours, even if the reference values are not met.
Starting conditions
Part Name
Electric
Symbol
RXYMQ-A Function
Compressor motor
M1C

RXYMQ4AVMK: 70 rps
RXYMQ4-6AYFK: 79 rps
Fan motor
M1F

With high pressure
OFF ←→ Step 4 ←→ Step 6
Electronic expansion valve
(Main)
Y1E

480 pulses
Electronic expansion valve
(Injection)
Y2E

0 pulse
Electronic expansion valve
(Refrigerant jacket)
Y3E

0 pulse: closed
0-480 pulse: open (when fin temperature increases)
Electronic expansion valve
(Refrigerant auto charge)
Y4E

Minimum pulse
Four way valve Y1S

OFF
Ending conditions
A lapse of 15 minutes
Tb>11°C continues for 30 seconds or more
OR
Indoor unit actuator During defrost
Fan
Thermostat ON unit OFF
Stopping unit OFF
Thermostat OFF unit OFF
Electronic expansion valve
Thermostat ON unit Defrost EV opening degree
Stopping unit Defrost EV opening degree
Thermostat OFF unit Defrost EV opening degree