8.Once the submaster loop is adjusted, remove all forced values and proceed with veri®cation and adjustment of master loop.
9.To check the master loop:
Create a demand in the master loop. For example: Force the actual space temperature to a value less than the heat- ing set point or greater than the cooling set point.
10.Observe system (loop) response for 10 to 20 minutes to verify stable control. After 10 minutes, if the output con- tinues to swing from full open to full closed, lower the MLG and observe again.
11.Do this until the loop operation is stable. After 10 min- utes, if the loop does not seem to respond (little change in submaster reference), increase the MLG and observe again. Do this until stable operation is achieved.
12.Once satis®ed with loop operation, remove all forced values which may have been initiated during this procedure.
13.Repeat Steps
NOTE: For better tuning, the building supervisor or service tool should be used to adjust the proportional and integral terms. Contact your Carrier representative for more details.
IAQ Control Loop Adjustment Ð The IAQ (indoor air quality) control loop is different from the other control loops. It has one gain value that can be adjusted in the serv-
ice subfunction ( ) under IAQG
gain). This gain is used to speed up or slow down the response of the economizer dampers to the difference be- tween the IAQ set point and the IAQ sensor. If the econo- mizer is moving too slowly, then the gain needs to be increased. If the economizer moves too rapidly and over- shoots the set point, then the gain should be reduced.
Lead/Lag Circuits Ð Lead/lag circuits and compres- sors are shown in Table 20.
Table 29 Ð Index of Lead/Lag Circuits and
Compressors
UNIT 48/50MP | 62L | 70M | 82N, 90P, 10R |
LEAD CIRCUIT | A | A | A |
Compressor, Lead | A1 | A1 | A1 |
Compressor, Lag | * | A2 | A2 |
LAG CIRCUIT | B | B | B |
Compressor, Lead | B1 | B1 | B1 |
Compressor, Lag | * | * | B2 |
*Circuit only has 1 compressor.
Final Checks Ð Ensure all safety controls are opera- ting, control panel covers are on, and the service panels are in place.
Recheck all set points against project speci®cations. Com- plete
NOTE: If the REMOTE START function is used in this ap- plication, set the LOCAL/REMOTE switch to REMOTE (On) at the end of
CONTROL SYSTEM
General Ð The control system consists of the following components:
·standard processor module (PSIO 8088 or PSIO1)
·options processor module (PSIO 8052 or PSIO2)
·two standard
·keypad and display module (HSIO or LID)
·enthalpy sensor
·thermistors
·pressure transducers
·accessory humidity sensors
·space temperature sensors (standard T55 and accessory T56)
·
·check ®lter switch
Components
PROCESSOR MODULE NO. 1 Ð The PSIO1 module moni- tors and processes the following inputs, outputs, and system information:
Inputs:
·transducers
·thermistors
·switches
Outputs:
·
·integrated economizer motor (4 to 20 mA)
·optional supply duct static pressure control (VFD) (4 to 20 mA)
·optional modulating power exhaust control (VFD) (4 to 20 mA)
System Information:
·generates alert and alarm information (via transducer, ther- mistor, and sensor inputs)
·supports CCN level II communications
·supports digital air volume (DAV) interface
NOTE: The correct module address for the PSIO1 is 01 (S1 set at 0; S2 set at 1).
PROCESSOR MODULE NO. 2 Ð The PSIO2 module sup- ports the sensors used for:
·humidity control
·
·
·smoke control
·superheat monitoring (only when accessory transducer ther- mistor kit is
In addition, the PSIO2 supplies the outputs for humidity and hydronic heating coil control and a discrete output with timed clock control (for outdoor building or parking lot lights).
NOTE: The correct module address for the PSIO2 is 31 (S1 set at 3; S2 set at 1).
NOTE: The correct module addresses for the DSIO1 and DSIO2 modules are 19 and 49, respectively. Set the switch closest to the mounting plate at 1 (DSIO1) or 4 (DSIO2), and the other switch at 9 (both modules).
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