ECR International Dunkirk DCBF-125 Installation, Operation And Maintenance Manual page 104

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 1.
Connect LWCO device to the system ground. Ground 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
120 V/60 HZ
L
1
N
G
Conduit or Power
Supply cord
(Polarized)
A - LOW WATER CUTOFF
Electrical Conduit
J-Box
BLK
WHT
GND
34
• Locate LWCO sensing device in the supply
piping, above the minimum height of boiler.
See Figure A-2, Piping Diagram.
• Position control in HORIZONTAL piping to assure
proper boiler protection (upright or 90° rotation).
• 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 A-3.
• 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.
Low Water Cutoff (LWCO)
L
1
N
GND
(Polarized) 120 V/60 HZ
Cord Set From Boiler
120 V/60 HZ Socket
N.O
PN 240012875 REV. A [01/31/2020]