Watts AERCO EXT Installation, Operation & Maintenance Manual page 49

Ufly Controller and BCM for Modulex EXT
CHAPTER 6: BOILER COMMUNICATIONS MODULE (BCM)
2. Voltage control signal configuration
• Scroll to Parameter 341 and set it to the output voltage at lowest firing rate of boiler.
Default is 3V. See Figure 6-10 for lowest firing rate of each Modulex boiler.
• Set Parameter 313 to the output voltage at 100% boiling firing rate. Default is 10V.
• For example, MLX EXT 1100 2S: If Parameter 341 is set to 2V and Parameter 313 is
set to 10V, the variable speed pump control will send 0VDC at 5% boiler firing rate, and
10VDC at 100% boiler firing rate, varying linearly between the two voltages.
NOTE: Consult pump manufacturer for control signal specifications and set Parameter 341
accordingly to ensure it is high enough to enable the pump.
3. Scroll to Parameter 322 and set it to desired time. Parameter 322 controls the amount of
time, in minutes, that the pump will continue to run after the unit is shut down.
OMM-0159_A_A • 6/28/2022
Figure 6-9
Model Minimum Firing Rate
MLX EXT 450 2S
MLX EXT 600 2S
MLX EXT 800 2S
MLX EXT 1100 2S
MLX EXT 1500 2S
MLX EXT 2300 2S
MLX EXT 2600 2S
MLX EXT 3000 2S
Figure 6-10
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