34 Installing the System Piping
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.
3.6.2 Wiring Diagram - External LWCO
CNG1
CNK1
CNV3
CNV2
CNV1
CNC3
ZONE3
LWCO
ZONE2
ZONE1
CNC2
COM
NO
NC
COM
NO
NC
COM
NO
NC
AC24VN
AC24VL
LWCO
Neutr
al
Line
Line
LW
CO
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
Electric Shock Hazard
To prevent serious injury or death:
●
ALWAYS follow all applicable electrical codes
of the local authority having jurisdiction.
●
In the absence of such requirements, follow
the latest edition of the National Electrical
Code (NFPA 70) in the USA or the latest edition
of CSA C22.1 Canadian Electrical Code Part 1
in Canada.
●
ONLY licensed professionals should connect
the electrical components.
●
ALWAYS label all wires before disconnecting
them when you work on the controls.
●
Wiring errors can cause improper and
dangerous operation.
●
ALWAYS 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
Electric Shock Hazard
To prevent serious injury or death:
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.
