Terminal Block 2 Connection - Navien NCB-20LHWE Installation & Operation Manual

8.4.2 Connecting the Cylinder Stat
The boiler is designed to be connected to a Cylinder Stat. The
thermostat cables are to be connected to the terminals 3 and 4
of the terminal block 1.
8.4.3 Connecting the Outdoor Temperature
Sensor
The boiler is designed to be able to function with an outdoor
temperature sensor. The sensor cables are to be connected to
the terminals 5 and 6 of the terminal block 1.
38 Connecting Electrical Supplies
Detail View
1
2
3
4
5
6
Detail View
1
2
3
4
5
6
8.4.4 OpenTherm® Protocol
OpenTherm® is an industry standard modulating control
available from several control manufacturers and the NCB
LHWE boiler has an OpenTherm® interface. This enables
our modulating range of OpenTherm® room controls to be
1
2
3
4
5
6
OpenTherm® Protocol
NCB LHWE

8.5 Terminal block 2 Connection

The terminal block 2 is located below the front panel. External
devices powered by 230 VAC, such as a room stat and 3 port
diverter valve or 3-way valve, may be connected to the terminals
1-8, and the terminals 9 and 10 provide a low-voltage connection
for a cylinder temperature sensor. Refer to the following illustration
for details of the terminal block 2.
230 VAC 230 VAC
Room Stat Output
L N
L Call E
1 2 4 5
3
230 V live connections
CAUTION
230 VAC live voltage runs at terminals 1-8. Before
connecting devices to the terminal, ensure that the rated
Terminals 9 and 10 provide a low-voltage connection for
a cylinder temperature sensor.
Room Controller
3 port diverter valve Cylinder Temp.
or 3-way valve
Sensor
COM DHW CH
(N) (L) (L)
6 7 8 9
10
Low-voltage
connections