Aerco MODULEX EXT 321 - Page 89

MODULEX EXT 321, 481, 641, 802, 962, 1123 BOILERS
Installation, Operation & Maintenance Manual
OMM-0087_0F AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 89 of 146
GF-143 Phone: 800-526-0288 07/13/15
Table 4-6: BCM 3-Position and 2-Position Switch Functions
2-Pos Switch
(Enable/Disable)
3-Pos Switch
(I/O/II)
Position I
(NOTE 1)
Position O
(see NOTE 2)
Position II
(See NOTE 3)
O = OFF (Disable) DO NOT USE
The BCM is the Gate-way for
Modbus and external control.
The E8 does not control the
boiler and the BCM will not
take over the boiler if the
Modbus signal fails.
The E8 is the primary
controller and the BCM
allows monitoring through
Modbus, but will not take
over boiler if the E8 fails.
I = ON (Enable) DO NOT USE
The BCM is the Gate-way for
Modbus and external control.
The E8 does not control the
boiler and the BCM will take
over the boiler if the Modbus
signal fails. If E8 is in Standby
Mode, BCM will cycle the
pump with the boiler. If E8 is in
Day Mode, the E8 will
continuously run the pump.
The E8 is the primary
controller and the BCM
allows monitoring, and the
BCM will take over the boiler
if E8 fails. If E8 is in Standby
Mode, E8 will cycle the pump
(must use Enable/Disable). If
E8 is in Day Mode, the E8
will continuously run the
pump.
NOTES:
1) DO NOT set the 3-Position Switch to Position I.
2) Set the 3-Position Switch to Position O ONLY when controlling Boilers from an external
Controller via Modbus Communication. See Paragraph 3.1.2 of the E8 Controller User
Manual (GF-115-C) for setting HEAT Modes.
3) Position II is the Default position for the 3-Position Switch. Ensure it is set to this position
when it arrives from the Factory. See Paragraph 3.1.2 of the E8 Controller User Manual
(GF-115-C) for setting HEAT Modes.