AERCO Control System (ACS) - Manual (Page 60)

MC2: 04/23/13 Page 60 of 144
GF-131
AERCO Control System (ACS)
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288
Installation, Operation, and Maintenance Manual
OMM-0081_0D
NOTE
In the Revision C firmware and later, the BMSII will shut down the
last boiler firing when the Percent Output Level goes below the
BLR STOP LEVEL. The shutdown will be indicated by the second
line of the default display flashing. By the same token, as the
Percent Level Output rises from 0%, the second line of the default
(Operating Menu) display will flash until it reaches the BLR
START PERCENT and the Header temperature is below 'Setpoint
- DEMAND OFFSET'.
3.12 RELAY MENU
As the name implies, the RELAY MENU contains the options necessary to select the actions
performed by the System Start (SYS START), Fault Alarm (FLT ALARM) and Auxiliary (AUX)
Relays in the ACS.
3.12.1 SYS START TEMP
If an Outdoor Air Sensor is installed, this menu option is used to select the Outdoor
Temperature below which the System Start Relay is allowed to activate (close), provided that
the SYS START OPTION conditions specified below are satisfied. The percent level will always
remain at 0% until the System Start Relay is activated The System Start Relay will open if the
Outdoor temperature is above the value set for this option.
3.12.2 SYS START OPTION
The SYS START OPTION can be set to TEMP ONLY or TEMP AND LOAD. Selecting TEMP
ONLY means the System Start Relay will be active whenever the Outdoor Temperature falls
below the System Start Temperature (SYS START TEMP).
Selecting TEMP AND LOAD will cause the System Start Relay to activate if the Outdoor
Temperature falls below the System Start Temperature and the Percent of Load (Operating
Menu) is at or above the LOAD START PCT (Calibration Menu). It will deactivate (open) the
System Start Relay when the Percent of Load goes below the LOAD START PCT.
3.12.3 SYS START INTLK
The SYS START INTLK selects the Interlock associated with the System Start Relay activation
when SYS INTLK CONFIG is set for START ENABLED. Available settings include,
INTERLOCK 1 (default), INTERLOCK 2, or INTERLOCK 1&2.
3.12.4 AUX RELAY OPEN
The AUX RELAY OPEN setting is the Percent Level output below which the AUX Relay will
open if it was closed due to the conditions described by the AUX RELAY CLOSE setting.
3.12.5 AUX RELAY CLOSE
This determines the condition for which the AUX relay will close. If 100% FIRE RATE is
selected, the AUX relay will close when all available boilers are firing at 100%. If 100% AND
OFF (default) is selected, it will close when all available boilers are firing at 100% as well as
when no boilers are available and the boiler plant is below setpoint. This relay can trigger
emergency heat in the latter case.
3.12.6 FAULT ALRM RELAY
This setting tells the ACS which faults should activate the fault alarm relay. The default is ALL