Siemens SED2 Commissioning Manual page 92

Note: If an OFF1 or OFF3 are issued, the VSD output frequency ramps down as set in P1121
(ramp-down time) or P1135 (OFF3 ramp-down time).
r2294 CO: Act. PID output
Displays the PID output in [%].
Unit: % Min: -
Details When PI is enabled, the output limits are ramped up from 0 to the limits set in P2291 (PID output upper limit) and P2292
(PID output lower limit). Limits prevent large step changes appearing on the output of the PID when the VSD is started.
Once the limits have been reached, the PID controller output is instantaneous.
These ramp times are used whenever a RUN command is given.
Note: r2294=100% corresponds to 4000 hex
P2303[2] CI: PID o/p offset
Selects the source of the PID output offset signal.
Unit: - Min: 0:0
Settings: 755=Analog input 1 setpoint
Index: P2303[0]=IN000: VSD in "Auto" mode
Note: The offset correction P2303 only works when the integral time of the PID controller is zero (P2285=0).
When analog input is selected, offset and gain can be implemented using parameters P0756 to P0760 (ADC scaling).
P2304 PID opening time
Sets actuator opening time constant for the PID controller.
Unit: s Min: 0
Details: See P2305 (PID actuator closing time)
P2305 PID closing time
Sets actuator opening time constant for the PID controller.
Unit: s Min: 0
Details: See P2304 (PID actuator opening time)
P2306 PID Acting Dir
Direct = 0 = increasing plant output causes increasing controller output Indirect = 1 =increasing
plant output causes decreasing controller output.
Unit: - Min: 0
Settings: 0: Direct acting (cooling sequence) – PID output increases, if PID feedback > PID setpoint (negative error)
1: Indirect acting (heating sequence) – PID output increases, if PID feedback < PID setpoint (positive error)
P2370 Motor staging stop mode
Selects stop mode for external motors when motor staging is in use.
Unit: - Min: 0
Settings: 0=Normal stop
P2371 Selection motor configuration
Selects configuration of external motors used for motor staging feature.
Unit: - Min: 0
Settings: 0:=Motor staging disabled
1:=M1=1X, M2= -,
2:=M1=1X, M2=1X
3:=M1=1X, M2=2X
4:=M1=1X, M2=1X
Details: Motor staging allows the control of up to 2 additional staged pumps or fans (M1 – M2), based on a PID control system.
The complete system consists of one pump controlled by the VSD with up to 2 further pumps / fans controlled by
contactors or motor starters. The contactors or motor starter are controlled by outputs of the VSD.
Note: Motor staging works only if PID controller is enabled (P2200=1).
P2372 Enable motor cycling
Enables motor cycling for the motor staging feature.
When enabled, the motor selected for staging / destaging
P2380. When staging, the motor with the least hours is switched on. When destaging, the
motor with most hours is switched off.
If staged motors are different sizes, the choice of motor is first based on the required power
output, and then if there is still a choice, on hours run.
Unit: - Min: 0
Settings: 0=Disabled
P2373 Motor staging hysteresis
Value as a percentage of the PID setpoint which must be exceeded by the PID error r2273
before the staging delay starts.
Unit: % Min: 0.0
P2374 Motor staging delay
Time that PID error r2273 must exceed motor staging hysteresis P2373 before staging occurs.
Unit: s Min: 0
3
Staging: With pump (or fan) cascading: Starting process of an additional motor with constant speed to increase output
4
Destaging: With pump (or fan) cascading: Stopping process of an additional motor with constant speed to decrease output
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Siemens
Building Technologies
Def: -
Def: 0:0
2224=Fixed PID setpoint
1st command data set (CDS)
Def: 0
Def: 0
Def: 1
3
Def: 0
Def: 0
Def: 0
Def: 20.0
Def: 30
Commissioning Guide
10 Parameterization
Max: -
Max: 4000:0
P2303[1]=IN001: VSD in "Hand" mode
Max: 65535
Max: 65535
Max: 1
Max: 1
1=Sequence stop
Max: 8
5:=M1=1X, M2=1X
6:=M1=1X, M2=2X
7:=M1=1X, M2=1X
8:=M1=1X, M2=2X
4
is based on the hours run counter
Max: 1
1=Enabled
Max: 200.0
Max: 650
2250=Output setpoint of PID-MOP
2nd command data set (CDS)
Level 3
Level 3
Level 2
Level 2
Level 2
Level 3
Level 3
Level 3
Level 3
Level 3
CM1G5192en
29.07.2010