GRUPAd.o.o.
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4. Outdoor control
(1) Compressor startup control
When the target running frequency master unit requested is over 60Hz, after compressor is running, it
must run for 3 minutes at 60Hz and 75Hz respectively. Then it will run at the target frequency.
When the target running frequency master unit requested is less than 60Hz, after compressor is running,
it must run for 3 minutes at 45Hz. Then it will run at the target frequency.
(2) Compressor operation control
It will be controlled by the target pressure.
In heating mode, the target high pressure:
When Ta>-7degree, target high pressure is 28Kg 0.8Kg;
When Ta<=-7degree, target high pressure is 24Kg 0.8Kg
In cooling mode, the target low pressure
When the running indoor capacity is over 5HP, if Ta>=21degree, target pressure Ps=8Kg (4degree)
0.5Kg; if 21degree>Ta>=15degree, target pressure Ps=7Kg(0degree) 0.5Kg.
(3) Fan motor control
a. In cooling mode
Startup procedure: When compressor starts up, outdoor motor will not run right now, when high pressure
reaches 2.1MPa, outdoor motor begins to run.
In operation, the motor will be controlled by high pressure. When high pressure reaches 2.1MPa, outdoor
motor will run at class-1 speed; if pressure is more than 2.1MPa, outdoor motor will increase one class
at interval of 60 seconds; if pressure is over 2.6MPa, outdoor motor will rise up to class-7. If pressure is
less than 1.9MPa for 60 seconds, fan motor will decrease one class. If less than 1.8MPa for 60 seconds,
fan motor will stop.
b. In heating mode
Motor control in startup procedure: before 4-way valve reverses in heating mode, outdoor motor will not
start up, after 4-way valve reverses, motor will run.
In operation, the motor will be controlled by low pressure. When low pressure is over 0.95MPa, fan motor
will stop; when low pressure is less than 0.75MPa, for every 60 seconds, fan speed will increase one
class; when it is less than 0.65MPa for 60 seconds, fan speed will be class-7 directly.
In defrosting, outdoor motor will stop. After the defrosting is over, 4-way vavle opens, outdoor motor will
start up at heating mode.
(4) Defrosting control
When one of the running outdoors reaches the defrosting condition, it will send defrosting signal to the
master unit. After the master unit receives defrosting signal, it will send defrosting signal to the running
outdoor. Then the slave outdoor will begin defrosting.
Entering condition:
When the unit has run in heating mode for 33 minutes and the compressor has run for 50 minutes
accumulatively since the last defrosting. By measuring the defrosting sensor TE and outdoor ambient
Summary of Contents for MRV II AV48NMVERA
Page 6: ...G R U P A d o o 06 2 Wiring work ...
Page 40: ...G R U P A d o o 40 ...
