3 bcm configured as back-up controller, 1 bcm back-up controller wiring, Gf-115-c – AERCO Modulex E8 Controls Guide User Manual
Page 64: Modulex e8 controller and bcm

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GF-115-C
Modulex E8 Controller and BCM
Operations and Maintenance Manual
OMM-0084_0D
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526- 0288
7.3 BCM Configured as Back-Up Controller
When the BCM is configured as the Back-Up Controller for the E8, it will assume control of the
Modulex Boiler if the E8 fails. In the event of an E8 Controller failure, the BCM will operate the
Modulex Boiler in the Constant Setpoint Mode (default setpoint = 180°F [82°C]). The primary
Boiler Pump must also be wired to the BCM so it will run when the BCM assumes control in the
Back-Up Mode.
If a setpoint temperature lower than 180°F is desired, the setpoint can be changed prior to boiler
start-up. Refer to
paragraph 7.3.1 for details.
7.3.1 BCM Back-Up Controller Wiring
The Primary Boiler Pump must be wired to BCM Connector Y4 as shown in
Figure 7-4. Also, if
a Constant Setpoint temperature lower than the default setting of 180°F (82°C) is desired in the
event of an E8 failure, the appropriate resistor must be connected across terminals 6 and 7 of
BCM Connector Y2 as shown in
Figure 7-5.
Figure 7-4: BCM Back-Up Controller Wiring