AERCO Control System (ACS) - Manual (Page 47)

MC2: 04/23/13 Page 47 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
Paragraphs 3.4 through 3.12 provide detailed descriptions of the
options contained in each of the menus shown in Figure 3-2. The menu
options appear in the first line of the VFD display and the corresponding
value or setting for the displayed option will appear in the second line of
the display.
Refer to
Appendix A for tabular summaries of all menu options showing
the allowable entry ranges and default values.
3.4 OPERATING MENU
The Operating Menu displays a number of key operating parameters for the ACS: These
parameters include:
HEADER TEMP, HEADER SETPOINT, OUTSIDE AIR TEMP, PERCENT OF LOAD, I/O
STATUS and RETURN TEMP (with optional Temperature Sensor).
All of the items in this menu are “Read-Only” and do not allow personnel to change or adjust
any of the displayed parameters. Since this menu is “Read Only”, it can be viewed at any time
without entering a password. The Operating Menu options are described in the paragraphs
which follow.
3.4.1 HEADER TEMP AND PERCENT OF LOAD
The HEADER TEMP menu option displays the actual water temperature (°F) measured by the
Header Sensor connected to HDR SEN terminals 4 and 5 of the ACS. If the Header Sensor is
not installed, HDR SENS ERROR will appear in the first line of the display. The red FAULT
indicator will also light. The Header Sensor MUST be installed for the ACS to operate properly.
The PERCENT OF LOAD option shows the percent level going from the ACS to each boiler in
the boiler plant. It also shows the number of boiler units that are operating.
NOTE
The ACS 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.
3.4.2 HEADER SETPOINT
This menu option is the setpoint temperature to which the control is set when operating in the
Constant Setpoint, Remote Setpoint or Outdoor Reset Mode. When in the Constant Setpoint
Mode, this value is equal to the Internal Setpoint setting in the Configuration Menu. When in the
Remote Setpoint Mode, this value is the setpoint equivalent to the remote analog signal or
Modbus value supplied to the unit. When in the Outdoor Reset Mode, this is the derived value
from the charts in Appendix D.
3.4.3 OUTSIDE AIR TEMP
The OUTSIDE AIR TEMP option shows the outdoor air temperature (°F) measured by the
Outdoor Air Sensor. This sensor is connected to OUT AIR SENS terminals 1 and 2 of the ACS.