Daikin VRV RXYQ72-384XAYCA, Руководство по обслуживанию

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SiUS342004EB Basic Control
Part 4 Functions and Control 92
5.5 Electronic Expansion Valve PI Control
Main electronic expansion valve EVM control
When the outdoor unit heat exchanging is performed via the condenser (Y5S or Y6S is set to OFF),
this function is used to exert PI control on the electronic expansion valve (Y1E or Y3E) so that the
condenser outlet subcooling degree (SC) will become constant.
When the outdoor unit heat exchanging is performed via the evaporator (Y5S or Y6S is set to ON),
this function is used to exert PI control on the electronic expansion valve (Y1E or Y3E) so that the
evaporator outlet superheating degree (SH) will become constant.
Subcooling electronic expansion valve EVT control
In order to make the maximum use of the subcooling heat exchanger, this function is used to exert
PI control on the electronic expansion valve (Y2E, Y5E or Y3E) so that the evaporator-side gas
pipe superheating degree (SH) will become constant.
SC = Tc – Tf SC:
Tc:
Tf:
Condenser outlet subcooling degree
High pressure equivalent saturated temperature
Liquid pipe temperature detected by heat exchanger liquid pipe
thermistor R4T, R5T
SH = Tg – Te SH:
Tg:
Te:
Evaporator outlet superheating degree
Suction pipe temperature detected by heat exchanger gas pipe
thermistor R8T, R9T
Low pressure equivalent saturated temperature
SH = Tsh – Tm SH:
Tsh:
Tm:
Evaporator outlet superheating degree
Suction pipe temperature detected by the subcooling heat
exchanger outlet thermistor R5T
Low or middle pressure equivalent saturated temperature