Modulex EXT Commercial Series Boilers User Manual
CHAPTER 5: E8 Controller and BCM Modules
OMM-0095_0H AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 85 of 144
GF-139 Phone: 800-526-0288 09/15/2017
TABLE 5-6: 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
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.
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.