These inputs are connect ed to the PSIO module. The P S I O also provides output s to t he:
guide vane actuator ; oil pump; oil heater; hot gas bypass (optiona l); motor cooling solen oid; and
alarm contact. The PSIO communicates with the LID, the SMM, and the optional 8-input
modules for user inter fa ce and starter managem ent .
Starter Management Module (SMM)
This module is located wit hi n the starter cabinet . T his m od ule initiates PSIO co m m and s 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 input s such as flow switches, line voltage, remote s ta rt contact, spare safety,
condenser high pressur e , oil pump interlock, mot or current signal, star t er 1M and run contacts,
and kW transducer input (optional). The SMM contains logic capable of safely shutting down t he
machine if communicat ion with the PSIO is lost.
Local Inte rface Device (LID)
The LID is m ounted to the co ntrol center a nd allows the o perator to inte rface with the PSIO
or other CCN devices. It is the input center for all local m ac hi ne set points, schedul es, set-up
functions, and optio ns . The LID has a STOP button, an al arm light, 4 buttons for lo gic inputs,
and a display. The function o f the 4 butt ons or ‘‘softk eys’’ are menu d riven and are shown on the
display directly abo v e th e key.