MAXA HWA1-A 0140, Руководство пользователя

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HWA1-A
Air/water chillers with axial fans
13
Example in cooling:
If the difference in temperature between water inlet and outlet is greater than P09 + P10 , the pump will run at maximum speed.
If the difference temperature between water inlet and outlet is less than P09 - 0.2°C , the pump will run the minimum speed.
In the other cases, the pump modulates trying to match the temperature difference with P09 . For the heating mode, the same
considerations are valid with replace only P06 with P09 . Please see paragraph 18.6 for changing the parameters.
Warning: During the DHW production mode, the pump is constrained to operate at its maximum speed.
In domestic hot water production mode, the pump will operate at the maximum speed.
8.7 Management of double circulator
You can configure the system to work with 2 pumps.
Parameter P13 shown the utilization logic:
•
P13 = 0: the pump will work for few hours.
No change of pump during operation, i.e. this setting can be selected only if it is needed to operate one pump.
•
P13 = 1: Periority of selection on pump 1.
•
P13 = 2: Periority of selection on pump 2.
Note:
Each pump has its own thermal protection digital input;
If one of the pumps is not available because of alarm, the other pump will be selected regardless of the P13 value.
9 FAN MOTOR CONTROL
The operation of the fan motors is depending on the value read by the pressure sensors.
There is a resettable
thermal device with immediate rearmament and will act only on fan motor.
9.1 AC fan motor
The condensation control is a function of the condensing pressure in chiller mode and the evaporation pressure in heat pump
mode.
The fan speed can be independently controlled from the compressors or under the CALL of the same compressors.
Pa
F05 for fan output mode
0: if all the compressors of the circuit are switched off and the fan is switched off.
1: The condensation control is independent from the compressor.
Switching off the fan motor is bypassed for a period of time equal to Pa
F12 from a circuit’s compressor start-up. During this
period if the regulator requires the cut-off the fan goes to the minimum speed.
9.2 Star-Delta (Y- ∆) fan motor
For cooling only “ HWA1-A ” versions, the fan motor is enabled to operate when at least one compressor is running; the fan speed
adjustment is depending on the condensation pressure.
If the condensation pressure exceeds F08 (default 25bar), the fan motor starts and the three-phase windings are starred
internally.
When the condensation pressure is greater than the parameter F14 (default 35bar), the fan motor windings connections
switch to triangle type and then the maximum fan speed is started.
If the condensation pressure is less than F14 - 5 bar, the fan motor windings switch to star.
If the condensation pressure is less than F08 - 5bar, the fan motor will stop operation.
9.3 EC fan motor control
The fan speed control in cooling mode occurs according to the diagram shown below, where:
F06 = Minimum fan speed in cooling mode;
F07 = Maximum silent fan speed in cooling mode
F08 = Set temperature/pressure to the minimum fan speed in cooling mode
F09 = Fan motor linear band in cooling mode
F10 = Delta cut-off of the fan