Emerson Autochangeover Controllers AC8 User Manual
Page 13
Introduction
5
J - Digital output
connectors
Each of the eight output connections is a two-state point: ON/OFF
(energized/de-energized).
An example of a field digital output point is an air unit On/Off control
circuit.
3.2.2: Connecting Digital Outputs
K - Status LEDs
Indicates the operational status of the controller board.
L - Digital output
loss-of-power
jumper
One of eight output jumpers. Each digital output has a jumper to set the
fail-safe position of the output point when power fails. The OFF position
makes the contact Normally Open (factory default). The ON position
makes the contact Normally Closed.
Note: The jumper position has no effect on the contact when the AC8
has power.
3.2.3: Setting the Digital Output
7.7.5: Configure Output for Loss of
M - Digital input
connectors
Each of the eight input connections is a two-state point: ON/OFF
(energized/de-energized).
An example of a field digital input point is a common alarm contact on an
air unit.
3.2.1: Connecting Digital Inputs
N - Digital input
status LEDs
Each input has an LED to indicate its status: ON/OFF (energized/de-
energized).
The emergency power operation (EPOP) input connection is a two-state
point: ON/OFF (energized/de-energized).
An example of an EPOP input point is a UPS or a generator.
3.2.5: Connecting the Emergency
Jumper to enable or disable emergency power operation (EPOP). Factory
default is disabled.
3.2.6: Setting the EPOP Jumper
Connection for an externally powered analog sensor that needs a
reference to ground.
3.3.2: Connecting the Analog Ground
Each of the four input connections accepts a 4/20 mA signal.
An example of a field analog input point is a temperature sensor.
Jumper to select voltage supplied for two-wire analog sensors. The
jumper supplies all four analog input connectors with the same voltage.
Factory default is 24VDC.
3.3.1: Setting the 12VDC/24VDC
T - SiteScan Web
connector (EIA422)
Connection to monitor AC8 from Liebert’s SiteScan Web graphical
monitoring package.
U - EIA485 connector
Not presently used
N/A
V - Serial interface
connector (RS232/
EIA574)
Connection for laptop or video terminal. Used for configuration and
monitoring using the Service Terminal Interface. Requires a null modem
cable for connectivity
(P/N 201258P1).
W - Phone line
connector
Connection for phone line. Used for pager notifications, service phone
number, and configuration and monitoring using the Service Terminal
Interface. Requires an RJ11 connector.
7.9.6: Setup Serv Ph Num - Enter
X - Power receptacle
(Transformer Module)
115VAC power receptacle to power laptop during configuration and
diagnostics. Receptacle not available on 230VAC Transformer Module.
2.4.1: Termination and Mounting
Y - Power On/Off
switch (Transformer
Module)
Power switch to turn power On/Off to both Transformer Module 24VAC
connectors and power receptacle.
2.4.1: Termination and Mounting
(Transformer Module)
One of the two 24VAC connectors for power (the second is also on the
right side of the Transformer Module near the top). Each connector is
rated for 40VA.
2.4.1: Termination and Mounting
AA - Modem
On-board modem with 9600 baud rate.
Indicates the operational status of the modem.
DIP switch used for resetting password to default.
Connection for the LCD on the enclosure door.
N/A
Adjustment contrast for the LCD on the enclosure door.
N/A
Connection for battery pack lead.
2.4.2: Connecting the Battery Pack
Power connection for the controller. Requires 24VAC.
Transformer Module used to convert 115VAC or 230VAC to 24VAC.
2.4.1: Termination and Mounting
Table 1
Controller board components (continued)
Item
Description
For more information, see: