Navien NHB Series Installation & Operation Manual page 103

11.6.4 Configuring a Cascade System
To view and configure the cascade settings, tap the Set button
( ) > Cascade on the screen.
Item
To enter the Cascade Setting Mode,
tap START.
The setting mode is entered and
the IDs of all boilers that can
communicate with the Main via
the RS485 communication line are
initialized.
The boilers whose IDs are initialized
by the Main are set to <Sub setting
mode>, if you press the OK button
for 3 seconds or more, the Main gives
you the ID and it is displayed on the
screen.
The Main periodically checks the
RS485 communication, and when
there is an ID request from the Sub,
1. Setting Mode
the ID is sequentially incremented
and added to the Sub (1 to 31).
Tap OK in the Main to complete
the cascade setting. In the Main
and the Sub with assigned IDs, the
pop-up windows will be closed and
the cascade setting mode will be
completed.
The Home screen is automatically
changed into the cascade screen
as soon as the cascade setting is
complete.
In Main setting mode, if no input is
detected for 60 minutes, the boiler
resumes normal operation without
cascading.
Description
Item
Select this option on the main unit
of a cascade system to end cascade
operation.
Enter main setting mode to reassign
IDs and begin a cascade system
2. System Off again.
If a sub unit has a network
communication problem, select this
option on the sub unit to exclude
the individual unit from the cascade
system.
Set the cascade strategy (control type).
Default: ECO
Note
3. Operation Strategy
Set the ventilation type.
4. Vent Type Setting range: Common/Individual
Default: Common
Set the number of initial activating
units in the cascade system.
5. Initial Activating
Units Setting range: 0 – 32
Default: 0
Tap ( ) to go to the next page.
Item
Set the minimum number of the boilers
for the cascade system.
1. Minimum
Operation Unit
Setting range: 1 – 32
Default: 1
Set the heating capacity standard when
adding boilers to the cascade system.
(Applied if Operation Strategy is set to
Custom.)
2. Unit On HC
Setting range: (Unit Off HC + 20%) -
(Max. Cascade heat - 5%)
Default: 70%
Description
For more detailed information
on the operation strategies,
refer to "Setting the Operation
Strategy" on page 105.
Description
Operating the Boiler 103