Xylem MM 705D User Manual
INSTRUCTION MANUAL
No. 11, 11M and 11MV
Replacement Switch
For use on Series 61, 64, 764, 67,
767, 69 and 70 Low Water Cut-Offs
11 General Purpose (BLACK terminal panel)
11M Manual Reset Option (BLACK terminal panel)
11MV Millivolt / 24V Option (RED terminal panel)
Electrical Ratings
Motor Switch Rating
(Amperes)
Voltage Full Load Locked Rotor Pilot Duty
120 VAC
240 VAC
NOTE: 11MV is rated at 24VA @ 24 VAC to 120 VAC
7.4
3.7
44.4
22.2
• Before using this product read and understand instructions.
• Save these instructions for future reference.
• All work must be performed by qualified personnel trained in the proper
application, installation, and maintenance of plumbing, steam, and electrical
equipment and/or systems in accordance with all applicable codes and
ordinances.
• To prevent electrical shock, turn off the electrical power before making
electrical connections.
• The low water cut-off switch 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.
• We recommend that secondary (redundant) Low Water Cut-Off controls be
installed on all steam boilers with heat input greater than 400,000
BTU/hour or operating above 15 psi steam pressure. At least two controls
should be connected in series with the burner control circuit to provide
safety redundancy protection should the boiler experience a low-water
condition. Moreover, at each annual outage, the low water cutoffs should
be dismantled, inspected, cleaned, and checked for proper calibration and
performance.
• To prevent serious personal injury from steam and hot water make sure
there is a discharge line from the blow down valve to a proper place of
disposal.
• To prevent a fire,do not use this low water cut-off to switch currents over
7.2A, 1/3 HP at 120 VAC or 3.6A, 1/3 HP at 240 VAC, unless a starter or
relay is used in conjunction with it.
•
California Proposition 65 warning! This product contains chemicals known
to the state of California to cause cancer and birth defects or other
reproductive harm.
Previous controls should never be installed on a new system. Always
•
install new controls on a new boiler or system
Failure to follow this warning could cause property damage, personal
injury or death.
CAUTION:
A more frequent replacement interval may be necessary based on the con-
•
dition of the unit at time of inspection. McDonnell & Miller's warranty is one
(1) year from date of installation or two (2) years from the date of manufacture.
120 VA at
120 or 240 VAC
!
WARNING
MM-705D
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 millivoltpotential gas valve control systems or 24VAC burners. 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.
120V or 24V BURNER AND FEEDER WIRING
TO BURNER
SAFETY
SWITCH
JUMPER
0
1
3
0
NEUTRAL WIRE
0
2
4
0
HOT WIRE
ELECTRIC
FEEDER
OR ALARM
SCHEMATIC OF TWIN SWITCH
INTERNAL OPERATION
0
0
1
3
0
0
1
3
0
0
1
3
0
MILLIVOLT/LOW VOLTAGE SYSTEM
TO BURNER
SAFETY
SWITCH
ELECTRIC
FEEDER
OR ALARM
NORMAL
2
WATER LEVEL
4
0
FEEDER OR
0
2
ALARM
4
0
OPERATING LEVEL
0
LOW WATER
2
CUT-OFF
4
0
OPERATING LEVEL
0
0
1
2
3
4
0
0
MILLIVOLT
GENERATOR/
TRANSFORMER
24 VOLT
TRANSFORMER
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" provides a contact only for an alarm at low water
and is NOT intended for use with an electric
feeder.
RESET
BUTTON
RESET
BUTTON
12
34
12
34
NORMAL WATER LEVEL
LOW WATER CUT-OFF
ALARM LEVEL
CAUTION
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.
NEUTRAL
HOT
(OPTIONAL)
RESET
BUTTON
BURNER
12
34
TRANSFORMER
ALARM
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