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User’s Manual
23
3.5.12. SETTINGS
WATER PRE-HEATER
Pump start temp
– setting for the temperature limit, that
forces the pump to continuous operation for initial freezing
protection
Range: -10..20
Default: 5
Pump kick
– timer that forces the circulation pump to run for
short period of time (30s) in speci
fi
ed intervals.
That prevents the mechanical sealings from sticking and
damage.
HMI ADVANCED
WATER PRE-HEATER
Pump start temp
5,0°C
Pump kick
Day
Back-water setp
40,0°C
Range:
No - function disabled
Day - function activated daily
Week - weekly
Month - monthly
Back water setp
– setpoint for back water temperature
regulator. Special PI regulator works in two operating modes.
First is normal heating mode, when the AHU is working.
Regulator prevents the back water from dropping below the
temperature limit.
Note! Main temperature has got lower priority than back-water
control!
Second mode is anti-freezing protection, when the AHU is
stopped in Off mode. The regulator maintains the back water
temperature equal to the setpoint value, in order to prevent
returning too hot water to the boiler system.
Note!
Back-water control functionality is optional and must be
enabled in Configuration mode of the controller.
Note!
The pre-heating coil works out of the standard cooling/
heating sequence. It is intended just to keep the constant
temperature in specified place, e.g. to heat up outside air
before entering the heat recovery unit.
3.5.13. SETTINGS
INIT HEATING
T
1
– lower scaling external temperature
T
2
– upper scaling external temperature
Y
1
– heating rate at T1 temperature
Y
2
– heating rate at T2 temperature
t_a
- time to force the valve to 100% opening, regardless to
the external temperature, in order to
fi
ll the pipeline with the
hot water
t_b
– time the unit stays with calculated heating rate
Note! Total time is t_a + t_b . These settings are common for
initial heating of pre-heater and secondary heater, if both are
present in the AHU.
HMI ADVANCED
INIT HEATING PRE-HW
Y2 50%
Y1 20%
T1 -40°C T2 -10°C
t_a 30s
t_b 60s
3.5.14. SETTINGS
FAN PI REGULATOR
Recovery frost protect
- special PI regulator to manage
supply fan speed reduction in case of freezing conditions. If
the limit temperature is reached, the regulator reduces the
frequency converter output by speci
fi
ed max. value in Hz
K
p
- proportional gain
T
i
- integrational time
HMI ADVANCED
FAN PI REGULATORS
Recovery frost protect
K
p
T
i
Y
min
Y
max
