Dunkirk Excelsior EXB Series - Manual (Page 7)

7
Blocked Vent Safety Switch Pressure Tubing
Connections
Check tubing connections on all Boilers prior to fi ring unit.
Beckett NX has low and high side tube, vacuum side goes
to air intake box, pressure side goes to overfi re pressure
probe. See Figure 11.
Riello BF low pressure side is open inside air tight burner
cover and high pressure side goes to overfi re pressure
probe.
Verify burner cover is air tight and all hole plugs are in
place.
BLOCKED VENT SAFETY SHUTOFF SYSTEM
Beckett NX Burner:
Refer to Table 2. Select head setting according to required
fi ring rate. Final adjustments are required once burner is
started.
Final Adjustments
• Tighten lock nuts and screws before making
measurements.
• Using suitable testing instruments for CO2 (or O2),
measure combustion products. CO2 in the stack should
be minimum of 12% CO2 at a trace of smoke. For
clean operation of burner, open air control to introduce
enough excess air into the system to reduce CO2 by
10% of original trace point.
EXAMPLE: 12% CO2 minus 1.2 (which is 10% of 12)
equals 10.8% CO2).
Riello 40BF Burner:
Refer to Figure 10. Check initial air shutter and head
settings. Remove burner cover and turn air shutter
adjustment screw (2) until top edge of air shutter (3) is in
alignment with corresponding number in Table 3.
NOTICE
Riello burner pressure gauge threads are British
Parallel Thread design. Test gauge with NPT fi tting
ruins pump body. Use Riello pressure gauge or
adapter.
Further adjustments must be made with burner cover in
place by unscrewing plug on cover. Turn screw clockwise to
increase combustion air or counter clockwise to decrease
combustion air.
• Shutter fi nal position will vary on each installation.
• Use instruments to establish proper settings for
maximum CO2 and smoke spot reading of zero.
• Re-insert plastic cap over air adjustment hole before any
measurements.
Blocked Vent Safety Shut Off System (BVS)
Direct vent Boiler is equipped with Blocked Vent Safety shut
off system (BVS). Safety circuit shuts burner off in event of
combustion air blockage or venting blockage.
It is best to have burner shutter and or head settings close
to Table 2 or 3.
Beckett NX
BVS pressure switch is wired in series with CAD cell. See
Wiring Diagram, Figure 12.
Riello 40BF
BVS pressure switch is wired in series with terminals 10
and 11 on 530SE control. See Wiring Diagram, Figure 13.
Oil Burner Operation
Once Boiler fl ue pipe and intake pipe are completely in-
stalled. In absence of burner manufacturer’s instructions,
use following instructions to set burner:
• Shut off electrical power to Boiler.
• Install oil pressure gauge to pressure port on oil pump.
(Riello requires special adapter)
• Check air settings for initial fi ring in Table 2 or 3.
• Restore electrical power to Boiler.
• Start Boiler. Bleed all air from fuel oil lines.
• Close purge valve and fi re unit.
• When Boiler has reached “steady state” (after
approximately 5 minutes), remove bolt (test port) from
center of Appliance Adapter to Boiler.
• Set combustion air control to get TRACE to ZERO
smoke.