AERCO KC1000 Low NOx Boiler July 2011 - Manual (Page 18)

INSTALLATION
2-8
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 5R5-184), BMS -Operations Guides.
2.6.4 REMOTE SETPOINT and DIRECT
DRIVE MODES
The KC1000 Boiler can accept several types of
signal formats from an Energy Management
System or other source to control either the
setpoint (Remote Setpoint Mode) or air/fuel
valve position (Direct Drive Mode) of the Boiler.
These formats are:
4 to 20 mA/1 to 5 Vdc
0 to 20 mA/0 to 5 Vdc
PWM – (Pulse Width Modulated signal. See
paragraph 2.7.4)
Network – (RS485 Modbus. See para. 2.7.7)
While it is possible to control one or more boilers
using one of the above modes of operation, it
may not be the method best suited for the
application. Prior to selecting one of the above
modes of operation, it is recommended that you
consult with your local AERCO representative or
the factory for the mode of operation that will
work best with your application. For more
information on wiring the 4 to 20 mA / 1to 5VDC
or the 0 to 20 mA / 0 to 5 VDC, see paragraph
2.7.3.
2.6.5 COMBINATION MODE
NOTE
Only BMS Model 168 can be utilized for
the Combination Mode, not the BMS II
(Model 5R5-384).
With a Combination Mode unit, field wiring is
between the unit’s I/O Box, the CCP
(Combination Control Panel), and the BMS
Model 168 (Boiler Management System). The
wiring must be done using a shielded twisted
pair of 22 AWG wire. Polarity must be
maintained between the unit, the CCP, and the
BMS. For further instructions and wiring
diagrams, refer to the GF-108 Boiler
Management System Operations Guide and the
CCP-1 data sheet.
2.7 I/O BOX CONNECTIONS
The types of input and output/signals and
devices to be connected to the I/O Box terminals
shown in Figure 2.11 are described in the
following paragraphs.
CAUTION!
DO NOT make any connections to the I/O
Box terminals labeled “NOT USED”.
Attempting to do so may cause equipment
damage.
2.7.1 OUTDOOR SENSOR IN
An outdoor air temperature sensor (AERCO Part
No. 122790) will be required mainly for the
Indoor/Outdoor Reset mode of operation. It can
also be used with another mode if it is desired to
use the outdoor sensor enable/disable feature.
This feature allows the boiler to be enabled or
disabled based on the outdoor air temperature.
The factory default for the outdoor sensor is
DISABLED. To enable the sensor and or choose
an enable/disable outdoor temperature, see the
Configuration menu in Section 3 and Appendix
A.
The outdoor sensor may be wired up to 200 feet
from the boiler and is connected to the
OUTDOOR SENSOR IN and SENSOR
COMMON terminals in the I/O box (see Figs.
2.10 and 2.11). Wire the sensor using a twisted
shielded pair cable of 18-22 AWG wire. There is
no polarity when terminating the wires. The