Liebert RAC2-8 • 1
Section 1: Introduction The Liebert RAC2-8 remotely controls from two to eight environmental
units. Each unit is assigned to a Zone (room) from 1 to 4. In Zone 1, the
largest room, the temperature and humidity can be monitored. The
common alarm output from each unit is monitored and annunciated by
the RAC2-8. Up to 20 system alarms can be stored with time and date
stamp. All alarms are latching and must be manually cleared.
See SECTION 5 —
INSTALLATION for special
instructions when using the RAC2-8
with Liebert mini-MATE, mini-MATE
Plus, and DataMate environmental
control systems.
The most important control functions are Autochangeover,
Autosequencing, and Standby Testing. Each unit can be assigned a
Running or Standby status.
Autochangeover turns on a Standby unit if a Running unit in the same
zone has an alarm. The Running unit (with alarm) will be turned off if
that control option is selected. Each unit will return to its previous
status when the alarm is manually cleared.
Autosequencing balances unit run-times by changing Standby units to
Running (and Running units to Standby) at programmed time intervals.
Standby Testing turns on Standby units at programmed intervals to test
their operation. Note that Autosequencing and Standby Testing cannot
both be selected at the same time.
Other control functions include Manual Override, E mergency Power
Operation, Power Failure Mode, Password, and Programmable Delays.
Refer to SECTION 4 — GLOSSARY OF CONTROL FUNCTIONS
for more details.
System outputs include Humidity Lockout Relay, Optional Control
Lockout Relay, and Common Alarm. Communication ports are
EIA-232 for terminal or printer, a modem port, and a proprietary
EIA-422 port for communication to a Liebert SiteScan monitoring
system.
The RAC2-8 can be operated locally from the built-in control panel or
remotely from an optional terminal (EIA-232 communication). This
manual shows examples of several typical display screens during both
local and remote operation.