OM AGSD-1
27
Table 3, Enable Sources
Unit
Switch
Input
Control
Source
Setpoint
Remote
Switch
Input
Key-pad
Entry
BAS
Request
Unit
Enable
OFF x x
x
x
OFF
x SWITCHES
OFF x
x OFF
ON SWITCHES
ON x
x
ON
ON KEYPAD x OFF x OFF
ON KEYPAD x ON x ON
ON NETWORK x
x OFF OFF
ON NETWORK
OFF x
x OFF
ON NETWORK
ON x ON ON
Example:
1.
If the Control Source is set to Switches, the field-installed remote Stop Switch controls
enabling. If the unit-mounted On/Off switch is either On or Off, the unit will be
disabled if the remote switch is Off. If the unit-mounted On/Off switch is On, the unit
will be enabled if the remote switch is On.
2.
With the unit-mounted switch On, if the Control Source is Network, and the BAS signal
is Off, the unit is not enabled. If a Remote Switch is Off, the unit is not enabled. If a
Remote Switch is ON and the BAS input is On, the unit will be enabled.
Chiller Control Source Options:
Set Unit Setpoints Screen #1 (shown below) has three fields: “Enable”, “Mode” and
“Source.”
Unit Setpoints
SET UNIT SPs (1)
Enable=On
Mode= COOL
Source = KEYPAD
1.
The Enable field can only be used with Source = Keypad. To enable and disable the
chiller through the keypad, any other control inputs including unit and pumpdown
switches and BAS controls are ignored. The Enable field toggles between On and Off.
2.
The Mode field is an informational display, showing the active control mode of the
chiller. It is used as an input only when the source is set to keypad. Only then can this
field be changed manually.
3.
The Source field has three options, “SWITCHES”(default), “KEYPAD”, and “BAS
NETWORK”.
a.
Switches source is used when there is no BAS interface used. This allows the unit
switches to function as pumpdown and shutdown switches for the circuit. This
option is used with applications using the remote start/stop input and not using a
BAS interface.
b.
Keypad source is used to override BAS or remote start/stop commands. This would
be used for servicing only.
c.
BAS Network source would be used for those applications using “MODBUS”,
“BACnet”, or “LON” communications through a building automation system. BAS
Protocol is set at Set Unit Setpoints item #14.
Summary of Contents for AGS 225D
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