Navien NFB-175H, Руководство по установке, Страница: 31 / 135

31 Installing the System Piping
Refer to the “3.6.9 Wiring Diagram - Air Handler” on
page 45 for wiring connections.
WARNING
●
The boiler, when used in conjunction with an
air conditioning system, must be installed so
that the chilled medium is piped in parallel
with the heating boiler. Appropriate valves
must be used to prevent the chilled medium
from entering the boiler.
●
If the boiler is connected to heating coils
located in air handling units where they
can be exposed to refrigerated air, use flow
control valves or other automatic means to
prevent gravity circulation of the boiler water
during the cooling cycle.
Configuring a Zone System
The NFB-H boiler can control up to 3 zones utilizing
zone valves or zone pumps. After installing the
system, the boiler operation must be configured
accordingly using the front panel.
To configure a zone system:
On the front panel, press the Menu button ( ) to
enter the setting menu, and then select 2. Space
Htg Operation > 2.Zone Settings .
3.5.1 Examples of System Applications
Refer to the following examples to properly
implement a system for space heating, DHW
supply, or both. These examples are provided to
suggest basic guidelines when you install the boiler
system. However, the actual installation may vary
depending on the circumstances, local building
codes, or state regulations. Check the local building
codes and state regulations thoroughly before
installation, and comply with them fully.
Air Handler Interface
The Navien NFB-H boiler can control the operation
of an air handler when a thermostat is used in
combination with the air handling unit. The Air
Handler Interface is designed to stop air handler
operation when the boiler’s space heating function
is not operating due to DHW supply demands, boiler
errors, or low water conditions.
The air handler contacts (A/H) turn off when the
following conditions arise:
●
The PCB DIP SW2 (Set of 8 Switches) #7 is set to
ON.
●
Thermostat is turned off.
●
The boiler is supplying DHW, or it is in stand-by
mode for DHW demand.
●
Level 2 or higher errors occur.
●
The boiler is turned off.
Thermostat Configuration for the Air
Handler Interface
Set the PCB DIP SW2 (Set of 8 Switches) #7 to down
position (OFF) to use a thermostat with the Air
Handler.
1 2 3 4 5 6
O
N
O
N
1 2 3 4 5 6 7 8