![](/images/new-backgrounds/1078616/78616107x1.webp)
to control the machine. The 19XL uses 3 pressure transducers and 8 thermistors to sense pressures and temperatures. These are connected to the PSIO module. The PSIO also provides outputs to the: guide vane actuator; oil pump; oil heater; hot gas bypass (optional); motor cooling solenoid; and alarm contact. The PSIO communicates with the LID, the SMM, and the optional
Starter Management Module (SMM)
This module is located within the starter cabinet. This module initiates PSIO commands for starter functions such as start/stop of the compressor, start/stop of the condenser and chilled water pumps, start/stop of the tower fan, spare alarm contacts, and the shunt trip. The SMM monitors starter inputs such as flow switches, line voltage, remote start contact, spare safety, condenser high pressure, oil pump interlock, motor current signal, starter 1M and run contacts, and kW transducer input (optional). The SMM contains logic capable of safely shutting down the machine if communications with the PSIO are lost.
Local Interface Device (LID)
The LID is mounted to the control center and allows the operator to interface with the PSIO or other CCN devices. It is the input center for all local machine set points, schedules,