Burnham SCG, Installation & Service Instructions Manual

Page: 53 / 96

5
VI. Electrical
A.
General.
Install wiring and electrically ground boiler
in accordance with authority having jurisdiction or, in
the absence of such requirements, follow the
National
Electrical Code
, NFPA 70, and/or CSA C22.1 Electrical
Code.
B.
A separate electrical circuit must be run from
the main electrical service with an over-current
device/disconnect in the circuit. A service switch is
recommended and may be required by some local
jurisdictions. Install the service switch in the line
voltage “Hot” leg of the power supply. Locate the
service switch such that the boiler can be shut-off
without exposing personnel to danger in the event of
an emergency. Connect the main power supply and
ground to the three (3) boiler wires (black, white and
green) located in the junction box at the inside top of
the boiler jacket. If a low water cutoff is to be used,
connect the low water cutoff so that all 120V power
to boiler is interrupted if the low water cutoff’s switch
opens.
C.
Refer to Figures 28 and 29 for details on the internal
boiler wiring.
DANGER
Positively assure all electrical connections are unpowered before attempting installation or service of
electrical components or connections of the boiler or building. lock out all electrical boxes with padlock
once power is turned off.
WARNING
Failure to properly wire electrical connections to the boiler may result in serious physical harm.
Electrical power may be from more than one source. Make sure all power is off before attempting any
electrical work.
Each boiler must be protected with a properly sized over-current device.
Never jump out or make inoperative any safety or operating controls.
The wiring diagrams contained in this manual are for reference purposes only. Each boiler is shipped with
a wiring diagram attached to the front door. Refer to this diagram and the wiring diagram of any controls
used with the boiler. Read, understand and follow all wiring instructions supplied with the controls.
NOTICE
All wire, wire nuts, controls etc. are installer supplied unless otherwise noted.
NOTICE
This boiler is equipped with a high water temperature limit located inside the internal wiring of the boiler.
This limit provides boiler shutdown in the event the boiler water temperature exceeds the set point of the
limit control. Certain Local Codes require an additional water temperature limit. In addition, certain types
of systems may operate at temperatures below the minimum set point of the limit contained in the boiler.
If this occurs, install an additional water temperature limit (Honeywell L4006 Aquastat) located in the system
piping as shown in the Water Piping and Trim Section of this manual. Wire as indicated in the Electrical
Section of this manual.