1 constant setpoint mode, 2 indoor/outdoor reset mode, 3 boiler management system mode – AERCO KC1000 Boiler equipped with C-More version 3.04 User Manual
Page 17: Installation

INSTALLATION
2-7
2.6.1 CONSTANT SETPOINT MODE
2.6.2 INDOOR/OUTDOOR RESET MODE
This mode of operation increases supply water 
temperature as outdoor temperatures decrease. 
An outside air temperature sensor (AERCO PN 
122790) is required. The sensor MUST BE 
wired to the I/O Box wiring terminals (see Figure 
2.11). For more information concerning the 
outside air sensor installation, refer to paragraph 
2.7.1. For programming and setup instructions 
concerning the indoor/outdoor-reset mode of 
operation, refer to Section 5, paragraph 5.1. 
The Constant Setpoint Mode is used when it is 
desired to have a fixed setpoint that does not 
deviate. No wiring connections other than 
electrical supply connections are required for 
this mode. However, if desired, fault monitoring 
or enable/disable interlock wiring can be utilized 
(see paragraphs 2.7.9 and 2.7.10).
.
Figure 2.11
I/O Box Terminal Strip
2.6.3 BOILER
MANAGEMENT
SYSTEM
(BMS) MODE
NOTE
BMS Model 168 can utilize either pulse 
width modulation (PWM) or RS485 
Modbus signaling to the Boiler. BMS II 
Model 5R5-384 can utilize only RS485 
signaling to the Boiler. 
When using an AERCO Boiler Management 
System (BMS), the field wiring is connected 
between the BMS Panel and each Boiler’s I/O 
Box terminal strip (Figure 2-11). Twisted 
shielded pair wire from 18 to 22 AWG must be 
utilized for the connections. The BMS Mode can 
utilize either pulse width modulation (PWM) 
signaling, or RS485 Modbus signaling. For PWM 
signaling, connections are made from the 
AERCO Boiler Management System to the 
B.M.S. (PWM) IN terminals on the I/O Box 
terminal strip. For RS485 Modbus signaling, 
connections are made from the BMS to the 
RS485 COMM terminals on the I/O Box terminal 
strip. Polarity must be maintained and the shield 
must be connected only at the AERCO BMS. 
The boiler end of the shield must be left floating. 
For additional instructions, refer to Chapter 5, 
paragraph 5.6 in this manual. Also, refer to GF-
108M (BMS Model 168) and GF-124 (BMS II 
Model 5R5-384), BMS -Operations Guides. 
