Connect wiring — general information
General wiring requirements
Electric shock hazard. Can cause severe
personal injury or death if power source,
including service switch on boiler, is not
disconnected before installing or servic-
ing.
•
Installations must follow these codes:
•
National Electrical Code, ANSI/NFPA 70, lat-
est edition and any additional national, state
or local codes.
•
In Canada, CSA C22.1 Canadian Electrical
Code Part One and any local codes.
•
Wiring must be N.E.C. Class 1. If original wire as
supplied with boiler must be replaced, type 105°C
wire or equivalent must be used. Supply wiring to
boiler and additional control wiring must be 14
ga. or heavier.
•
Provide electrical ground at boiler as required
by codes.
Thermostat wiring
•
Install thermostat on inside wall away from influ-
ences of drafts, hot or cold water pipes, lighting
fixtures, television, sun rays or fireplaces.
•
Follow instructions with thermostat. If it has a
heat anticipator, set heat anticipator in thermostat
to match power requirements of equipment con-
nected to it. Boiler wiring diagrams give setting for
standard equipment.
Junction box (furnished)
•
Junction box houses electrical connections for all
boiler components.
•
“P” boilers have harnesses furnished.
•
“A” boilers are furnished with burner and limit
harnesses.
•
All field-provided high voltage wiring must be
sheathed in flexible metal conduit.
•
Connect incoming line voltage “HOT” wire to
service switch, and neutral wire to white wire.
Field-install equipment ground wire to green wire
with wire nut.
•
Service switch (15 amp) is provided with boiler. “A”
boilers — install switch as shown.
•
Some local codes may require an emergency shut-
off switch installed at a location away from boiler.
Follow local codes.
Burner wiring
•
Burner harness incorporates a disconnect plug,
providing a convenient way to disconnect wiring
when burner mounting door is opened.
•
All “P” boilers have a power disconnect plug in-
stalled on burner.
•
On “A” boilers, mount the plug (provided in steam
trim carton) on the burner housing as shown
in Figure 18, page 27, or Figure 20, page 29. For
Carlin burners, screw burner plug into threaded
conduit coupling, then mount this assembly to the
burner housing using the chase nipple. Route wires
through housing and make connections in burner
junction box as shown in boiler wiring diagram.
High temperature limit
•
To comply with ASME, UL 726 or Canadian re-
quirements, an additional high temperature limit
is needed.
•
Install the secondary control in the supply piping
between boiler and isolation valve.
•
Set the control to a minimum of 20˚F above the set
point of the combination control.
•
The maximum allowable set point is 220˚F.
•
Wire the control as shown on page 26 (float-type
LWCO) or page 28 (probe-type LWCO).
Part number 550-141-829/1211
24
GOLD
SGO
OIL-FIRED NATURAL DRAFT STEAM BOILER — SERIES 3 —
Boiler Manual
SERVICE TECHNICIAN ONLY — read and follow completely.
