M&m 2 3, Wiring alternatives when using mixed voltages, The uni-match – Xylem MM 226C Series 69 Low Water Cut-Offs For Steam Boilers User Manual
Page 6
24V Burner/120V Feeder
120V Burner/120V Feeder
or
24V Burner/24V Feeder
Connect a wire from the "Hot" side of the power supply to the
water feeder terminal 3, and low water cut-off terminal 2.
Connect a wire from the neutral side of the power supply to the
water feeder terminal 2, and to the neutral side of 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 terminal 1 of the water feeder.
W
or
1
N
or
2
H
or
3
BURNER
1
2
3
4
N
H
WF2-U-120 or
WF2-U-24
Supply Voltage
SAME as Feeder
69
120V Burner/24V Feeder
W
or
1
N
or
2
H
or
3
BURNER
24V
TRANSFORMER
1
2
3
4
N
120 VAC
SUPPLY
H
WF2-U-24V
69
Switch
Initial
Initial
Dwell/Feed
Position
Dwell
Feed
Cycles
M&M
60
60
Repeats until LWCO
seconds
seconds
reactivates the
burner circuit
2
90
90
One
seconds
seconds
3
100
100
One
seconds
seconds
2
3
M
&M
M&M
2
3
Wiring Diagrams (continued):
Series 69 Low Water Cut-off with M&M Model WF-2-U Electronic Water Feeders
The Uni-Match
®
water feeders have a three-position slide
switch which initiates a dwell period specific to the position of
the switch. If the system condensate raises the boiler water
level above the cut-off level during the dwell period, no addi-
tional water will be added to the boiler. Once the dwell period
has passed, the feeder will be activated and water will be
added to the boiler. The feeder will be deactivated when the
LWCO reactivates the burner circuit.
The position of the slide switch also sets the length of the
dwell period, the length of time valve is open and the number
of dwell/feed cycles. The control is set with the slide switch in
position 3 and can be changed in the field after installation.
The chart on the right indicates the cycles and length of
dwell/feed cycles for each position.
6
W
or
1
N
or
2
H
or
3
BURNER
24V
TRANSFORMER
1
2
3
4
N
120 VAC
SUPPLY
H
WF2-U-120
69
WIRING ALTERNATIVES
WHEN USING MIXED VOLTAGES