U.S. Boiler Company LE DV Series, Installation, Operating And Service Instructions

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APPENDIX A: LOW WATER CUT OFF (LWCO) ON HOT WATER BOILERS
(continued)
A 24 VAC LWCO is used primarily for gas fired boilers
where a 24 volt control circuit exists within the boiler.
However, a 24 VAC LWCO can only be used if the
boiler manufacturer has provided piping and wiring
connections and instructions to allow for this
application.
How to Test
Shut off fuel supply. Lower water level until water
level is BELOW the LWCO. Generate a boiler demand
by turning up thermostat. Boiler should not attempt to
operate. Increase the water level by filling the system.
The boiler should attempt to operate once the water
level is above the LWCO.
APPENDIX B: FIGURES
Figure
Number
Page
Number
Description
Section I - General Information
Figure 1A 5 LEDV Packaged Water Boiler with Beckett AFII Burner
Figure 1B 6 LEDV Packaged Water Boiler with Riello BF Burner
Section II - Pre-Installation
Figure 2 8 Minimum Installation Clearances To Combustible Materials
Figure 3 9 Legs Secured to Skid
Section III - Packaged Boiler Assembly - Trim and Controls
Figure 4 10 Hinge Installation & Assembly, LEDV Boiler
Figure 5A 11 Relief Valve and Boiler Control Assembly Details - Beckett AFII Burner
Figure 5B 12 Relief Valve and Boiler Control Assembly Details - Riello BF Burner
Figure 6 12 Limit Sensor Insertion
Section IV - Water Piping and Trim
Figure 7 13 Recommended Piping for Combination Heating and Cooling (Refrigeration) System
Figure 8A 14 Recommended Water Piping for Circulator Zoned Heating Systems - Supply Side Circulator
Figure 8B 15 Recommended Water Piping for Zone Valve Zoned Heating Systems - Supply Side Circulator
Section V - Venting
Figure 9 17 Vent Terminal Location
Figure 10 18 Intake Terminal Location
Figure 11 19 Vent Installation
Figure 12 19 Vent Connector, Un-Assembled
Figure 13 20 Vent Connector, Assembled
Figure 14 20 Air Intake Installation
Section VI - Electrical
Figure 15A 24 Schematic Wiring Diagram, Cold Start Control with Beckett AFII Burner
Figure 15B 25 Schematic Wiring Diagram, Cold Start Control with Riello BF Burner
Figure 16 26 Schematic Wiring Diagrams For All Burner Options w/Various Oil Primary Controls