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Siemens Building Technologies Commissioning Guide CM1G5192en
HVAC Products 10 Parameterization 26.02.2003
Dependency:
If F max (P1082) is greater than P2000 (reference frequency), either P2000 or P2291 (PID output upper limit) must be
changed to achieve F max.
Note:
P2291=100 % corresponds to 4000 hex (as defined by P2000 [reference frequency] )
P2292 PID output lower limit
Sets the lower limit for the PID controller output in [%]
Unit: % Min: -0.00 Def: 0.00 Max: 100.00
Level 2
Dependency:
A negative value allows bipolar operation of the PID controller
Note:
P2292=100 % corresponds to 4000 hex
P2293 Ramp-up /-down time of PID limit
Sets maximum ramp rate on output of PID
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 ap-
pearing 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
Unit: s Min: 0.00 Def: 0.00 Max: 100.00
Level 3
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: - Def: - Max: -
Level 3
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 Def: 0:0 Max: 4000:0
Level 3
Settings:
755=Analog input 1 setpoint 2224=Fixed PID setpoint 2250=Output setpoint of PID-MOP
Index:
P2303[0]: VSD in Auto mode P2303[1]: 2nd command data set (CDS)
Note:
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 Def: 60 Max: 65535
Level 2
Details:
See P2304 (PID actuator closing time)
P2305 PID closing time
Sets actuator opening time constant for the PID controller
Unit: s Min: 0 Def: 60 Max: 65535
Level 2
Details:
See P2304 (PID actuator closing 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 Def: 1 Max: 1
Level 2
Settings:
0 Direct acting (cooling sequence)
1 Indirect acting (heating sequence)
P2370 Motor staging stop mode
Selects stop mode for external motors when motor staging is in use
Unit: - Min: 0 Def: 0 Max: 1
Level 3
Settings:
0=Normal stop 1=Sequence stop
P2371 Selection motor configuration
Selects configuration of external motors used for motor staging feature
Unit: - Min: 0 Def: 0 Max: 8
Level 3
Settings:
0=Motor staging disabled
1=M1=1X, M2= 0
2=M1=1X, M2=1X
3=M1=1X, M2=2X
Details
Motor staging allows the control of up to 2 additional staged pumps or fans, based on a PID control system. The com-
plete 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.
P2372 Enable motor cycling
Enables motor cycling for the motor staging feature
When enabled, the motor selected for staging / destaging is based on the hours run counter
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 motor
size, and then if there is still a choice, on hours run
Unit: - Min: 0 Def: 0 Max: 1
Level 3
Settings:
0=Disabled 1=Enabled
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