MAXA i-HPV5H 0140, Manual

Page: 14 / 36

Controllo per i-HPV5
Chillers and Inverter Air/Water heat pumps with axial fan
14
In practice, in cooling mode, if the temperature difference between the inlet and outlet is greater than P09 + P10, the circulator runs at maximum
speed, but if the difference is less than P09 - 0.2°C, it runs at minimum speed; in the remaining cases, the pump modulates the speed propor -
tionally. In heating mode, the same considerations apply, replacing parameter P06 with parameter P09.
In sanitary production the circulator always runs at maximum speed.
8.6 SYSTEM VENTING
The control allows the use of a manual system venting function with the circulator at maximum speed.
To enable the function the operations to follow are:
• Set unit to OFF
• Access with maintenance privilege PRG -> PSS -> PRG -> (enter installer password) -> PRG
• Press UP and DOWN simultaneously for 3 seconds.
It is possible to exit the system venting cycle manually by pressing the MODE/ESC , button,or by pressing UP and DOWN keys simultaneously for
3 seconds.
CAUTION: during this function the flow switch alarm is disabled, the maintenance technician must guarantee that there is
water inside the system.
9. COMPRESSOR ON/OFF LOGIC
The restart of compressors is in operation of a set point refered to the inlet and outlet water temperature. It is based on calculation of ∆T,set that
is the difference between outlet and inlet water temperatures, detected while the compressor for thermoregulation is turning off.
9.1 REGULATION IN COOLING MODE
• Tw,out,set = setpoint in cooling mode
•
∆T,set
= Tw,out,set – Tw,in,set
• b05 = compressor delta cut-off set = 0,2°C (default)
• b25 = delta cut-on compressor regulation set = 2°C
RPM
Tw,out (outlet water temp.)
Tw,out,set
HzMaxReg
OFF
HzMin
b05 ∆T,s et + b25
• The compressor shutdown is regulated by parameter b05: the compressor shutdown when Tw,out < Tw,out,set - b05
• The compressor restart when Tw,out > (Tw,out,set + ∆T,set + b25) EXCEPTION : if ∆T,set > 8°C , the compressors restart when the discharge
probe temperature is lower than the setpoint 10°C:
Tw,out > (Tw,out,set + 10°C).
9.2 REGULATION IN HEAT MODE
•
Tw,out,set
= setting setpoint in heat mode
• ∆T,set = Tw,out,set – Tw,in,set
• b05 = compressor regulation delta cut-off = 0,2°C (default)
• b25 = compressor regulation delta cut-on = 2°C