Operation - 11 and 11mv, Operation - 11m, Caution – Xylem MM 705D No. 11, 11M and 11MV Replacement Switch for use on Series 61, 64, 764, 67, 767, 69 and 70 Low Water Cut-Offs User Manual
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OPERATION - 11 AND 11MV
The No. 11 switch contains two (2) single pole single
throw switches to control a water feeder and the low
water cut-off. The low water cut-off switch is between
terminals marked "1" and "2". The switch at terminals
"3" and "4" can be used to control a McDonnell &
Miller electric water feeder or a low water alarm. The
No. 11MV has the same switch arrangement as the
No. 11. This switch has special contacts for the low
water cut-off terminals "1" and "2" for use on millivolt-
potential gas valve control systems or 24VAC burn-
ers. Some millivolt systems have terminals on the
gas valve marked "L1" and "L2" which can be utilized
for wiring a limit switch. Others have both thermostat
and pressure control in series; if so, simply wire this
pair of terminals in series with them. A second switch
(at "3" and "4") can be used on 24 volt circuits only
for an alarm or electric feeder control.
OPERATION - 11M
The No. 11M is a SPDT switch with a latching
mechanism. Terminal "2" is the common. At
normal water level, a circuit through terminal
"1" is closed. It latches open in a low water
condition.
Depressing the manual reset button unlatches
the mechanism after normal water level has
been restored to the control. Terminal "4" pro-
vides a contact only for an alarm at low water
and is NOT intended for use with an electric
feeder.
Do not electrically connect water feeder
to a No. 11M. This model includes a
manual reset feature, failure to follow
this caution could result in boiler
flooding and property damage.
!
CAUTION
0
2
0
4
1
0
3
0
0
2
0
4
1
0
3
0
SCHEMATIC OF TWIN SWITCH
INTERNAL OPERATION
NORMAL
WATER LEVEL
FEEDER OR
ALARM
OPERATING LEVEL
0
2
0
4
1
0
3
0
LOW WATER
CUT-OFF
OPERATING LEVEL
1
2
3
4
NEUTRAL
HOT
ALARM
RESET
BUTTON
BURNER
TRANSFORMER
(OPTIONAL)
NORMAL WATER LEVEL
1
2
3
4
RESET
BUTTON
1
2
3
4
RESET
BUTTON
LOW WATER CUT-OFF
ALARM LEVEL
ELECTRIC
FEEDER
OR ALARM
TO BURNER
SAFETY
SWITCH
0
2
0
4
1
0
3
0
MILLIVOLT/LOW VOLTAGE SYSTEM
24 VOLT
TRANSFORMER
MILLIVOLT
GENERATOR/
TRANSFORMER
NEUTRAL WIRE
ELECTRIC
FEEDER
OR ALARM
HOT WIRE
TO BURNER
JUMPER
SAFETY
SWITCH
0
2
0
4
1
0
3
0
120V or 24V BURNER AND FEEDER WIRING