Operating Procedures
ARTC-SVX002A-EN
33
Overview Module
Module En/Dis
Pressing this button enables or disables a module. It is
used for testing and maintenance purposes. If module is
disabled, it's excluded from Client control compressors
sequence. Not accessible for 'user'
Module Status
Possible options:
1. Module ON. Module is ready to run.
2. OFF by Schedule. Module operates according to
predefined schedule and is currently off as scheduled.
3. OFF by DI. Module is off by opened state of PLC DI1.
4. OFF by Keypad. Module is off by Module En/Dis button.
5. OFF by Alarm. Module is locked out by one of the major
alarms.
6. OFF by Client. Module is switching between control
states Client / Server / Stand-alone.
7. OFF by System. Module is off by one of the System Off
conditions.
8. Man Mode. Module is in manual mode.
Module Cntrl Status
Possible options:
1. Client. Module acts as a Client Module. Client Module
performs temperature control for either heating or
cooling loads. It also acts as a Supervisor when
communicating with Server Modules and defines how
many modules need to run its compressors in order to
satisfy heating or cooling controlled temperatures.
2. Server. Module acts as a Server Module. Conditions for
the module to be a Server Module:
a. Its PLC has been assigned IP address from Servers
addresses range
b. It's communicating with Client Module
c. Client Module exists on the network, other words
Client PLC meets Client Module conditions (see
Client Status below).
d. Stand-alone. Module doesn't meet either Client
Module or Server Module conditions.
Client Status
Applies to Client PLC only. Possible options:
1. Client ON. All Client Modules conditions are satisfied
by module.
2. Waiting … All Client Modules conditions are satisfied
and module is counting down a delay before acquiring
Client ON status.
3. OFF by Sensor. System cooling or heating temperature
sensor failed.
4. OFF by no Servers. Client PLC communicates with no
Servers.
a. Client Status states 3 or 4 will cause all the modules
to run in Stand-alone mode. These failing
conditions are false at normal Client / Server
operation.
b. Client Online (Applies to Server PLC only). LED is
green - Server PLC is communicating with Client
PLC; LED is gray - Server PLC is not communicating
with Client PLC.
Lead Module
Indicates which module is currently a Lead Module in the
chiller.
Evap / Cond Circuits
Displays Evaporator inlet and outlet temperatures and an
opening status of Evaporator Isolation Valves as well as
Ambient Temperature.
Control Temperature
Local module hot or chilled water temperature control
sensor
Temperature Setpoint
Local module heating or cooling temperature control
setpoint. Can be adjusted by 'tech' user only.
Demand Compressors
Cooling or Heating Demand value in number of requested
compressors.
Temp Cntrl Settings
Viewable / adjustable for 'tech' user only.
•
Temp Diff +. Temperature control differential above
setpoint or positive dead band (DB).
•
Temp Diff -. Temperature control differential below
setpoint or negative DB.
•
Both of them define the temperature control DB.
•
Temp Stage-Up Delay. When next compressor has
been staged up, this delay has to elapse before next
compressor is allowed to stage up.
•
Temp Stage-Down Delay. When next compressor
has been staged down, this delay has to elapse
before next compressor is allowed to stage down.
On/Off Button
Used to turn Server PLC module on / off in Stand-alone
Mode. For Client PLC module, On / Off Button on the Home
Screen serves the same purpose.
Overview Circuits
Refrigerant temperatures / pressures are displayed:
suction pressure; discharge pressure; suction
temperature; suction super heat temperature.
