Navien NFB-175H, Руководство по установке, Страница: 36 / 135

36 Installing the System Piping
3.6.2 Wiring Diagram - External LWCO
COM
NO
NC
ZONE1
COM
NO
NC
ZONE2
COM
NO
NC
ZONE3
AC24VN
AC24VL
LWCO
R
W
C
R
W
C
W
C
Neutral
Line
Line
LWCO
LWCO
Note
The boiler supplies 24 VAC at the LWCO
power terminals (CNC3).
For terminal type LWCO devices, a typical wiring
method is shown below (same voltage for control
and burner circuit):
LWCO
Terminals
Neutral
Jumper
Line LWCO
To Boiler LWCO Terminals
3.6 Examples of Electrical
Connections
WARNING
Improperly connecting the electrical supplies
can result in electrical shock and electrocution.
Follow all applicable electrical codes of the local
authority having jurisdiction. Connecting the
electrical components should be performed
only by a licensed professional.
CAUTION
Label all wires before disconnecting them
when you work on the controls. Wiring errors
can cause abnormal and dangerous operation.
Verify proper operation after servicing.
Note
The installation must comply with
National Electrical Code and any other
national, state, provincial or local codes
or regulations. In Canada, CSA C22.1
Canadian Electrical Code Part 1, and any
local codes.
Wiring must be N.E.C. Class 1. If original
wiring as supplied with boiler must be
replaced, use only type 105 °C wire or
equivalent.
Boiler must be electrically grounded
as required by National Electrical Code
ANSI/NFPA 70 – latest edition.
3.6.1 Accessing the Terminal Strips
DANGER
You must ensure that the boiler is disconnected
from the electrical supply before carrying out
any servicing inside the boiler and, particularly,
on the electric terminal strips.
To access the PCB, carefully follow the steps below:
1. Turn off the power supply to the boiler.
2. Unfasten the 4 latches (2 at the top and 2 at the
bottom) to remove the front cover and gain
access to the internal components.