41
LOW WATER CUTOFF
Low Water Cut Off - Heating Only and Combi Boilers
These guidelines are supplied when necessary to install
an additional Low Water Cut Off (LWCO), for sensing a
low water level condition in a boiler, as required by the
Authority Having Jurisdiction.
Follow LWCO manufacturer installation instructions for
type of LWCO selected in addition to these instructions.
LWCO shall be 120V/60HZ control and dry contacts sized
for load being connected. Wire control to boiler. See Figure
below.
Connect LWCO device to the system ground. Ground Boiler
in accordance with the requirements of the authority
having jurisdiction or, in the absence of such requirements,
with the National Electrical Code (NEC) or Canadian
Electrical Code CEC.
LWCO WIRING DIAGRAM
Low Water Cutoff (LWCO)
Electrical Conduit
J-Box
120 V/60 HZ
Conduit or Power
Supply cord
(Polarized)
L
1
N
G
GND
L
1
N
GND
BLK
WHT
120 V/60 HZ Socket
(Polarized) 120 V/60 HZ
Cord Set From Boiler
N.O
• Locate LWCO sensing device in the supply
piping, above the minimum height of boiler.
See Figure page 42, Piping Diagram.
• Position control in piping above boiler to assure
proper boiler protection.
• For proper operation, sensing element of the LWCO
control shall be positioned in the tee to sense the
main water stream. Maintain minimum 1/4” spacing
from pipe walls. Element shall NOT contact the rear,
or side walls of the tee. See Figure page 43.
• Install an air vent using a tee to avoid nuisance
shutdowns.
• Apply small amount of pipe sealant to threaded
connections.
• Arrange piping to prevent water dripping onto boiler.
• DO NOT install water shutoff valve between boiler
and LWCO sensing device.
PN 240012875 REV. C [10/01/2021]
Summary of Contents for MACF-115
Page 2: ...MACF 150 ...
Page 4: ...MAHF 125 ...
Page 74: ...70 A 1 MODEL 100 Heat Only APPENDIX A WIRING DIAGRAMS 240013371 REV B 10 01 2021 ...
Page 75: ...71 A 2 MODEL 125 Heat Only APPENDIX A WIRING DIAGRAMS 240013371 REV B 10 01 2021 ...
Page 76: ...72 APPENDIX A WIRING DIAGRAMS A 3 MODEL 165 Heat Only 240013371 REV B 10 01 2021 ...
Page 77: ...73 APPENDIX A WIRING DIAGRAMS A 4 MODEL 115 Combi 240013371 REV B 10 01 2021 ...
Page 78: ...74 A 5 MODEL 150 Combi APPENDIX A WIRING DIAGRAMS 240013371 REV B 10 01 2021 ...
Page 79: ...75 A 6 MODEL 205 Combi APPENDIX A WIRING DIAGRAMS 240013371 REV B 10 01 2021 ...
Page 80: ...76 NOTES 240013371 REV B 10 01 2021 ...
Page 81: ...77 NOTES 240013371 REV B 10 01 2021 ...
Page 82: ...78 NOTES 240013371 REV B 10 01 2021 ...
Page 117: ...33 MODEL 100 Heat Only 100 HEAT ONLY WIRING DIAGRAM PN 240012875 REV C 10 01 2021 ...
Page 118: ...34 MODEL 125 Heat Only 125 HEAT ONLY WIRING DIAGRAM PN 240012875 REV C 10 01 2021 ...
Page 119: ...35 MODEL 165 Heat Only 165 HEAT ONLY WIRING DIAGRAM PN 240012875 REV C 10 01 2021 ...
Page 120: ...36 115 COMBI WIRING DIAGRAM MODEL 115 Comb PN 240012875 REV C 10 01 2021 ...
Page 121: ...37 MODEL 150 Combi 150 COMBI WIRING DIAGRAM PN 240012875 REV C 10 01 2021 ...
Page 122: ...38 MODEL 205 Combi 205 COMBI WIRING DIAGRAM PN 240012875 REV C 10 01 2021 ...
Page 127: ...43 LOW WATER CUTOFF DETAIL LOW WATER CUTOFF NO NO YES PN 240012875 REV C 10 01 2021 ...
Page 132: ...48 3 FAULT SOLUTION SECTIONS PN 240012875 REV C 10 01 2021 ...