Navien NFB-175H, Installation Manual, Page: 111 / 135

111 Operating the Boiler
Item Description
2. Cascade System
Removal
Select this option on the
Main unit of a cascade
system to end cascade
operation.
●
Enter Cascade system
setting mode to
reassign IDs and begin
a cascade system 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.
3. Cascade Init-
operation Unit
Set the initial number of
activated boilers.
●
Setting range: 0 – 16
●
Default: 0
Note
Sub units of a cascade
system cannot use this
item.
4. Cascade ON HC
Offset
Adjust the staging of
boilers to be added to the
system load.
●
Setting range: - 20% –
+20%
(60 – 100% load)
●
Default: 0 (80% load)
Note
Sub units of a cascade
system cannot use this
item.
5. Cascade OFF HC
Offset
Adjust the staging of
boilers to be removed
from the system load.
●
Setting range: - 10% –
+10%
(20 – 40% load)
●
Default: 0 (30% load)
Note
Sub units of a cascade
system cannot use this
item.
Press the Back button ( ) to return to the previous
screen or menu.
Item Description
1. Cascade System
Setting
●
To enter the Cascade
Main setting mode,
select 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
2 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,
the ID is sequentially
incremented and
added to the Sub (1
to 16).
●
Select OK in the Main to
complete the cascade
setting, and the Main
and the assigned
Sub IDs will return to
<Normal operation
mode> and turn into
CASCADE ON state.
At this time, the Main
icon on the Main panel
lights up.
●
If the cascade setting
is idle for more than
1 hour, it returns to
<Normal operation
mode> and reverts to
CASCADE OFF state
automatically.