Electrical Wiring; Electric Power Supply; Install Your Thermostat - Dunkirk XEB-2 Installation Manual

All electrical work must conform to local codes as well
as the National Electrical Code, ANSI/NFPA-70, latest
revision. In Canada, electrical wiring shall comply with
the Canadian Electrical Code, CSA-C22.1.

ELECTRIC POWER SUPPLY

Run a separate 120 volt circuit from a separate
overcurrent protective device in the electrical service
entrance panel. This should be a 15 ampere circuit.
Locate a shut-off switch at the boiler. It must be turned
off during any maintenance. Connect 120 volt power
supply to aquastat terminals L1 (HOT) and L2.
The boiler, when installed, must be electrically
grounded in accordance with the requirements of
the authority having jurisdiction or, in the absence of
such requirements, with the National Electrical Code,
ANSI/NFPA No. 70-latest revision. Run a 14 gauge
or heavier copper wire from the boiler to a grounded
connection in the service panel or a properly driven
and electrically grounded ground rod.
!
WARNING
Turn off electric power at fuse box before making any
line voltage connections. Follow local electrical codes.
1. Thermostat calls for heat, powering the 1K relay
coil and closing contacts 1K1 and 1K2.
2. Circulator pump is powered through terminals C1
and C2.
3. Induced draft blower and transformer primary are
powered through terminals B1 and B2.
4. When blower gets up to speed and blower suction
pressure reaches pressure switch setpoint,
pressure switch contacts close sending 24 volts
to intermittent pilot control from transformer
secondary.
5. Pilot gas valve opens and spark initiates to light
pilot burner.
6. When pilot flame is proven, spark drops out.
7. Main gas valve opens and pilot burner ignites
main burners.
8. If boiler water temperature reaches high limit
setpoint, high limit contacts B-R open, cutting power
to blower and intermittent pilot control.

eleCtRICAl WIRING

!
SequeNCe of opeRAtIoN
22

INSTALL YOUR THERMOSTAT

The thermostat location has an important effect on
the operation of your boiler system. BE SURE TO
FOLLOW THE INSTRUCTIONS INCLUDED WITH
YOUR THERMOSTAT Locate the thermostat about
five feet above the floor on an inside wall. It may
be mounted directly on the wall or on a vertically
mounted outlet box. It should be sensing average
room temperature, so avoid the following:
THERMOSTAT LOCATIONS TO AVOID
DEAD
HOT SPOTS
SPOTS
Concealed pipes
Behind Fireplace
doors
TV sets
Radios
Lamps
Corners &
alcoves
Direct sunlight
Kitchens
Set heat anticipator at .2 amps, the 24 volt thermostat
connects to aquastat terminals T and T.
Burners extinguish and blower stops. Circulator
pump continues to run as long as the thermostat
continues to call for heat. When boiler water
temperature drops past the high limit setpoint
and through the differential, high limit contacts
B-R close, repeating steps 3-7.
9. If venting system becomes blocked, blower
suction pressure will drop below the pressure
switch setpoint, opening the pressure switch
contacts and cutting power to the intermittent
pilot control. Burners will extinguish, but blower
will remain powered as long as the thermostat
continues to call for heat. If venting system clears,
steps 4-7 will repeat.
10. Thermostat is satisfied, ending call for heat.
Relay coil 1K is de-energized, opening 1K1 and
1K2 contacts. Burners extinguish. Blower and
circulator pump stop.
COLD SPOTS
Concealed
pipes
or ducts
Stairwells -
drafts
Doors - drafts
Unheated
room on other
side of wall