Liebert Autochangeover Controllers AC8 - Manual

1
AC8
Product Specification/Installation Sheet
Description
The Liebert AC8 is ideal for coordinated control of systems
with redundant equipment, such as multiple environmental
units or pumps. When the AC8 controller detects an alarm in
an operating device, the AC8 enables a standby device and
controls the device in alarm as configured, either leaving that
device operating or disabling it.
The AC8 controller can also balance usage of devices by
rotating units through Operating and Standby modes
according to a user-defined schedule. This helps keep
redundant equipment operating efficiently and only when
needed. The AC8 can perform routine testing of standby
devices and alert personnel if a standby device fails an
operating test and requires attention.
The staging feature permits standby devices to be turned on
or off when a sensor detects specified levels. For example, the
AC8 might be configured to turn on a fan when the
temperature reaches 75°F, then turn on a second fan at 80°F.
When the temperature falls below 80°F, the second fan is turned off; when it drops below 75°F,
the first fan is turned off. Liebert’s TW420 Temperature Transmitter may be connected to any of
the four analog sensor inputs for staging and other functions.
Another capability of the AC8 is monitoring the status of connected devices and keeping
personnel apprised through local alarming. The AC8 employs local alarming and remote paging
services to keep personnel on-site and at remote locations apprised of the status of equipment.
The AC8 controller can interface with
anything that closes an electrical contact.
To improve process efficiency and
troubleshooting, the controller tracks data
in three types of logs: alarm, event and
trend.
The AC8 has both a local LCD interface
and a remote dial-up interface for
configuration and monitoring. Liebert’s
SiteScan Web may also be used for
monitoring, as well as some configuration
functions.
When an alarm condition arises, the AC8
displays alarm information, sounds an
audible alarm, changes the state of the
common alarm relay and turns connected
devices on or off according to user
configuration. If configured, the controller
also sends pager notifications.
For other applications, contact your local
Liebert representative or call
1-800-222-5877.
Features and Benefits
• Custom configuration for specific applications
• Paging capability—up to four pager numbers
• Preconfigured on-board modem
• Alarm, Event and Trend logs with time and
date stamp
• Battery backup to ensure alarm notification
• Backup and download configuration files
• User interface via RS232 or modem connection
• On-board audible alarm
• Configuration data permanently stored in non-
volatile Electrically Erasable Programmable
Read Only Memory (EEPROM) for protection
against power loss
• Real-time clock
• Status LEDs for verification and diagnostics