Xylem MM 226C Series 69 Low Water Cut-Offs For Steam Boilers - Manual (Page 4)

Wiring Instructions
• To prevent electrical shock, turn off the electrical power before making electrical connections.
• This low water cut-off must be installed in series with all other limit and operating controls installed on the
boiler. After installation, check for proper operation of all of the limit and operating controls before leaving
the site.
Failure to follow this warning could cause electrical shock, an explosion and/or a fire, which could result in
property damage, personal injury or death.
! WARNING
TOP LEFT BOTTOM RIGHT
TOP 1 2
3 4
Electrical connector is movable into any one of four positions illus-
trated, by simply removing two black headed screws and rotating
housing.
NOTE: This control should be wired with materials suitable for use
at 75˚C.
Switch Operation
The No. 11 switch can be identified by a black terminal panel. The
switch contains two (2) single pole single throw switches to control
the water feeder and the low water cut-off. The low water cut-off
switch is between terminals marked “1” and “2”. A second switch is
located between terminals marked “3” and “4”. This can be used to
operate a low water alarm or a McDonnell & Miller electric water
feeder.
Wiring Diagrams:
Series 69 Low Water Cutoff with M&M Model 101-A Electronic Water Feeders
120V Burner and 120V Feeder
BURNER
120 VAC
SUPPLY
1 2
3 4
N
H
101A
69
Using a wire nut, connect a wire from the neutral side of the power sup-
ply to one of the wires inside the feeder's junction box. (Does not make
a difference which one). Connect a wire from the "hot" side of the power
supply to terminal 2 of the Series 69 junction box. Connect the neutral
side of the power supply to the burner.
Connect the wire from the burner to terminal 1 of the low water cut-off.
Connect a "jumper" from terminal 2 to terminal 3 of the low water cut-off.
Connect a wire from terminal 4 of the low water cut-off to the remaining
wire in the 101-A water feeder.
24V Burner and 24V Feeder
BURNER
101A-24
120 VAC
SUPPLY
24V TRANSFORMER
(101-24V-48)
1 2
3 4
N
H
24V
69
Connect the "hot" wire from the boiler transformer to terminal 2 of the low
water cut-off. Connect the "hot" side of the water feeder transformer to
terminal 3 of the low water cut-off. Connect the neutral side of the boiler
transformer to the burner. Using a wire nut, connect the neutral side of the
water feeder transformer to the water feeder.
Connect the wire from the burner to terminal 1 of the low water cut-off.
Connect a wire from terminal 4 of the low water cut-off to the remaining
wire in the water feeder.
4
To prevent damage to the water feeder, a McDonnell
& Miller transformer Model 101-24V-48 must be used.
! IMPORTANT