D.4.A Cascade Parameters - Bradford White OmniTech BONH1250 Installation And Operation Instructions Manual

8.D.4.a Cascade Parameters
To navigate to the Cascade Parameters Screen, touch the Cascade Icon on the Configuration Screen, then touch the
Cascade Parameters Icon.
The Cascade Parameters Screen allows adjustment of the following parameters:
• Address – When manually addressing each boiler/heater for cascade operations, this parameter is used to set the
local boiler/heater address. Each boiler/heater must have a unique address. A boiler/heater with a value of 1 is the
lead boiler/heater. Lag boilers/heaters use values 2 through 8. When automatically addressing each boiler/heater, set
the lead boiler/heater to a value of 1. With a value of 1, the Cascade Auto-Config button is available to use, refer to
this parameter below for instructions for automatic addressing the lag boilers/heaters.
• Dynamic Address – This reflects the address of the local boiler/heater after it has been manually or automatically
addressed. After a boiler/heater has been manually/automatically addressed, setting this parameter to 0 will remove
the boiler/heater from cascade operations.
• Base / Drop Load – This button will get you to the Base / Drop Load screen which allows you to manually enter
the base firing percentage of the next cascading boiler as well as the firing point at which this boiler will drop the
remaining load to the next cascaded boiler.
• Lost Lead Backup Setpoint – When configured for Cascade Redundancy - Boiler Internal Set Point, this parameter
is the maximum outlet temperature the local boiler/heater is allowed to supply the system.
• Lag On Hysteresis - The value below the Max Lag Temp (Max Lag Temp – Lag On Hysteresis) that the boiler/heater
will turn on to satisfy an active cascade demand based on the local boiler/heater outlet water temperature. Max Lag
Temp is set at the Lead boiler/heater.
• Lag Off Hysteresis - The value above the Max Lag Temp (Max Lag Temp + Lag Off Hysteresis) that the boiler/
heater will turn off when satisfying an active cascade heat demand based on the local boiler/heater outlet water
temperature. Max Lag Temp is set at the Lead boiler/heater.
• Cascade Auto-Config – Once configured
as the lead boiler / heater, you can initiate
automatic addressing by pressing the 'Start'
option. This is only adjustable at the lead
boiler/heater. Once configured as the lead
boiler/heater, pressing this button will initiate
the lead boiler/heater to find and address all
lag boilers automatically.
• Cascade Release Demand
communications with the master is lost and
the lag units continue to satisfy the cascade
heat demand, pressing this button will remove
the heat demand.
NOTE: This only applies when configured for
cascade - Boiler Internal Set Point Control.
See Section 8.D.4.c on page 77
• Max Lag Temp – The maximum outlet
temperature a lag unit is allowed to supply the
system.
• Backup Mode Max Lag Power – The maximum
firing rate cascaded boilers will run at if the
system sensor is lost on the master.
NOTE: All boilers/heaters must be
wired for cascade operations prior to
performing Cascade Auto-Config.
C O N F I G U R A T I O N
- When
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