AERCO Control System (ACS) - Manual (Page 51)

MC2: 04/23/13 Page 51 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
ROUND ROBIN can be used at this time. When set to ROUND ROBIN, each networked boiler
is addressed individually in sequence. BROADCAST is currently not used for the ACS.
3.7.6 NETW BOILER Xx ADDRESS=Yyy
Up to 32 Network Boilers can be accommodated on the Modbus Network (Where Xx = 01 – 32
and Yyy = 001 – 127). Each Boiler must be assigned a unique address on the network ranging
from 001 to127. No addresses should be entered if automatic boiler detection is desired. Simply
set the MIN SLAVE ADDR and MAX SLAVE ADDR to the minimum and maximum address
range of the boilers. To program boiler addresses in the order you desire, enter them here and
set the MIN SLAVE ADDR and MAX SLAVE ADDR to zero.
3.8 FIELD ADJUST MENU
The FIELD ADJUST MENU contains the most extensive list of options compared to the other 8
Menu categories. The options in this menu allow you to adjust important parameters to suit the
specific needs of your ACS installation. Included are options to select the Header Mode and
Temperature Limits, Internal Setpoint, Building Reference Temperature, Reset Ratio and
Remote Signal. In addition, the Field Adjust Menu contains a series of options which can be
used to set up a Header Setpoint Offset Schedule for an entire week. Descriptions of the Field
Adjust Menu options:
3.8.1 HEADER SET MODE
The HEADER SET MODE option sets the Header Setpoint selection method for the ACS.
Allowable selections are: CONSTANT SETPT, OUTDOOR RESET or REMOTE SETPT.
(Default = CONSTANT SETPT).
3.8.2 HDR HIGH LIMIT
The HDR HIGH LIMIT option sets the maximum temperature setting allowed for the Header
Setpoint. This setting also defines the 20 mA temperature equivalent when operating in the
Remote Setpoint Mode using a 4 – 20 mA signal. The allowable setting range is from the HDR
LOW LIMIT to 220°F. (Default = 200°F).
3.8.3 HDR LOW LIMIT
The HDR LOW LIMIT menu option sets the minimum temperature setting allowed for the
Header Setpt. This setting also defines the 4 mA temperature equivalent when operating in the
Remote Setpoint Mode using a 4 – 20 mA signal. The setting range is from 40°F to the HDR
HIGH LIMIT. (Default = 40°F).
3.8.4 INTERNAL SETPT
The INTERNAL SETPT temperature is the HEADER SETPT used when CONSTANT SETPT is
selected for the HEADER SET MODE or when the ACS operates in the Failsafe Mode and
CONSTANT SETPT is selected as the FAIL SAFE MODE setting in the Configuration Menu.
3.8.5 RESET RATIO
This menu option is displayed only if the HEADER SET MODE is set to OUTDOOR RESET.
The RESET RATIO option setting defines the ratio of the increase in Header temperature with
respect to each degree decrease in Outdoor temperature starting from the Building Reference
Temperature (BLDG REF TEMP).
The Reset Ratio is adjustable from 0.3 to 3.0. (Default = 1.2). The Reset Ratio Charts provided
in Appendix D are suitable for most applications. However, if a special reset schedule is desired,