Operating The Bcm As A Backup Controller - Watts AERCO EXT Installation, Operation & Maintenance Manual

Ufly Controller and BCM for Modulex EXT
CHAPTER 6: BOILER COMMUNICATIONS MODULE (BCM)
setpoint equal to the value assigned for Parameter 39 (Maximum Setpoint) in the BCM. Do not
change the value of Parameter 39 as it also represents the maximum setpoint for the boiler
during normal operation.
If a different setpoint is desired for controller back-up operation, a resistor can be installed in
terminals 6 and 7 of connector Y2 in the Input/Output box and Parameter 799 must be set = 0.
NOTE: A resistor can be installed on terminals Y2 6/7, and Parameter 799 can be changed to
zero only if the normal operating mode is either Constant Setpoint or via Modbus (AERCO ACS,
BAS/EMS). A resistor cannot be installed on terminals Y2 6/7 if the normal operating mode is
Outdoor Reset or Analog Remote Setpoint because they are used for the outdoor air sensor or
analog input. (Do not change Parameter 799 to zero as it is used to define the function of the
same terminals for Outdoor Reset or Analog Remote Setpoint).
Figure 6-6: Installing Resistor to Change Default Setpoint
.

6.3.2 Operating the BCM as a Backup Controller

When the Ufly Controller fails or the external control signal from the Master ACS, EMS, or BAS is
lost, the yellow LED on the BCM will blink.
OMM-0159_A_A • 6/28/2022 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
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