15.DISCHARGE CONTROLS
15.1 Control Modes
The Discharge Control Mode (
1.3.x.1
) defines the preference of fans actuation and shutdown. To control the discharge, the
RCK-862
plus
has
the following control modes: Linear Mode, Rotation Mode, Dead Zone Mode, Dead Zone Mode with Rotation.
15.2 Types of discharge control
The discharge control can be carried out by monitoring the pressure or temperature variable. The type of control is adjusted according to the variable to
be used in the parameter Type of control (
1.3.x.2
).
Pressure
: When configuring the Control Type (
1.3.x.2
) for pressure, the
RCK-862
plus
uses the parameters related to pressure of
1.3.x.6
to
1.3.x.10
. In this type of control, a temperature sensor (
1.3.x.21
) can also be added to monitor the condenser refrigerant outlet
temperature (sub-cooling calculation).
Temperature
: When configuring the Control type (
1.3.x.2
) for temperature, the
RCK-862
plus
uses the parameters related to temperature
1.3.x.11
to
1.3.x.18
.
15.2.1 Linear Mode
15.2.1.1 Linear Mode linked only with digital fan outputs ON I OFF
Linear mode, when it only has digital outputs linked, controls the actuation and shutdown of each fan sequentially and with pressure / temperature
intervals of the same magnitude (step).
The
RCK-862
plus
uses a setpoint value and pressure or temperature hysteresis (depending on the type of control) to control the discharge.
Actuation Pressure value of the ‘’N’’ Output Actuation = Se (N x Step)
Shutdown Pressure value of the output ‘’N’’ Actuation = Se (N-1x Step)
In this case, each fan is associated with a digital output and the step is defined as 60/6 = 10 psi.
Step for activating the outputs
Step =
Digital hysteresis
Number of outputs
250
260
270
280
290
300
310
(psi)
F1
F1 + F2
F1 + F2 + F3
F1 + F2 + F3 + F4
F1 + F2 + F3 + F4 + F5
F1 + F2 + F3 + F4 + F5 + F6
OFF
Outputs
Pressure value for output ‘’N’’ actuation
Pressure value for output ‘’N’’ deactivation
Activation = Se (N x Step)
Activation = Se (N-1 x Step)
Example:
1.3.x.1
Control mode: Linear
1.3.x.3
Setpoint: 250 psi
1.3.x.5
Hysteresis of digital outputs: 20
1.3.x.24
Number of fans: 6
1.3.x.25
Fan 1 modulation: without modulation
1.3.x.39
Integral Time: Off
15.2.1.2 Inverter-modulated fan:
The control of fans with frequency inverter uses an analog output (0-10V).
Only fan 01 of each discharge line can be configured as an inverter. During operation, the inverter-modulated fan is the first to be actuated and the last to
be shutdown. Example: In item
1.3.x.25
o ‘’Modulation of fan 01'’ as ‘’Inverter’’ and select an analog output for the Inverter. You can select a digital
output for the start/stop function by selecting a digital output in the parameter Fan Digital output (
1.3.x.27
).
The working values of the output (maximum, minimum and start) can be configured in the menu Analog outputs
1.10
.
Integral actuation can be selected together with proportional (PI mode) using the parameter Integral Time (
1.3.x.39
).
Note:
When more than one fan is controlled by only a single proportional output, the number of fans (
1.3.x.24
) is set to 1 and Compressor
Modulation (
1.3.x.25
) as Inverter.
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