AERCO Control System (ACS)
CHAPTER 3
: Operation
11/22/2017
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, New York 10913
Page 55 of 139
OMM-0081_0F
Phone: 800-526-0288
GF-131
NOTE
For best efficiency, the Boiler Start Level (
BLR START LEVEL
)
and Boiler Stop Level (
BLR STOP LEVEL) of the ACS must be the
same values as all of the C-More Controls in the heating plant, i.e.
if the boilers are set to 20%/16% (Start/Stop levels), then the ACS
must be set to 20%/16%. These values must NEVER be set lower
than the values at the boilers.
3.9.8 MAX POWER INPUT
The Maximum Power Input (
MAX POWER INPUT)
sets the maximum Percent Level that the
ACS can ramp up the boilers to. This may be useful in an over-sized boiler plant. The
allowable entry range is from 50 % to 100% (default = 100%).
3.9.9 FAIL SAFE MODE
Selects the desired operating mode of the ACS if it loses its Outdoor Air Sensor when operating
in the Outdoor Reset mode, or loses its Remote Signal when operating in the Remote Setpoint
mode. If CONSTANT SETPT is selected as the FAIL SAFE MODE, the ACS will operate the
boilers to achieve a Header Setpt equal to the programmed Internal Setpt. If SHUTDOWN is
selected, it will shut down all the boilers.
NOTE
If the Header Sensor is lost, the ACS will shut down all the boilers.
3.9.10 LEAD BLR SELECT (Lead Boiler Selection)
The LEAD BLR SELECT option is used to select NETW BOILER 1 as the only lead boiler. This
boiler will be the first one fired and the last one shut down on the boiler plant. This boiler will not
be included in the rotation scheme. Be sure that the address of the boiler being selected is
programmed as NETW BOILER 1. The default selection for this option is NONE.
3.9.11 LAST BLR SELECT (Last Boiler Selection)
The LAST BLR SELECT option selects the boiler that is to be the last one fired and only after all
the
others have reached the maximum percent output. this boiler might be an older one that
must only be fired when absolutely needed. This boiler will not be included in the rotation
scheme. The default selection for this option is NONE.
3.9.12 ROTATE TIME
The boilers will normally rotate on a first-on, first-off basis. This option allows a timed rotation of
the boilers. At the selected time, the first-on, first-off rotation will take place. The default time is
set for 168 hours (1 week).
3.9.13 RET SENSOR MODE (Return Sensor Mode)
This option defines the use of the sensor connected to the Return Sensor input. When set to
NORMAL, it is sensing the return temperature of the boiler plant and therefore all the functions
that relate to this - PLANT DT LIMIT would now be active. When set to DHW/TANK TEMP, the
input is monitoring the domestic hot water temperature. When set to OFF (default), this input is
ignored.
3.9.14 PLANT DT LIMIT (Plant Delta-Temperature Limit)
This feature is active if the RET SENSOR MODE is set to NORMAL. This value defines the
maximum temperature difference allowed between the Header temperature and the Return
