Xylem MM 404J Series 93/193 and Series 94/194 Low Water Cut-Off/Pump Controllers For Steam Boilers and Level Control Applications - Manual

INSTRUCTION MANUAL
2
Electrical Ratings
Models with 5 or 5-M Switch Models with 7B or 7B-M Switch
Approximate
Distance Above
Cast Line Differential
Setting In. (mm) In. (mm)
Pump Off 2 3 /
16
(56) 1 1 /
16
(27)
Pump On 1 1 / 8 (29)
Burner On 1 3 / 8 (35) 1 3 / 8 (35)
Burner Off 0
Switch Settings
Values are ±
1 / 8
” (3mm)
NOTE: Due to the slower operation of some
motorized valves, complete valve opening or
closing may occur at slightly different
levels than indicated above.
Models with 5 or 5-M Switches
Approximate
Distance Above
Cast Line Differential
Setting In. (mm) In. (mm)
Valve Full 2 3 /
16
(56) 1 1 /
16
(27)
Closed
Valve Full
1 1 /
8
(29)
Open
Burner On
1 3 /
8
(35) 1 3 /
8
(35)
Burner Off 0
Models with 7B or 7B-M Switches
OPERATION Maximum Pressure:
Series 93/193: 150 psi (10.5 kg/cm
2 )
Series 94/194: 250 psi (17.6kg/cm 2 )
PUMP
OFF
BURNER
OFF
BURNER
“CUT-OFF LEVEL”
AT CAST LINE
2 3 /
16
"
(56mm)
PUMP OFF
PUMP ON
(27mm)
1 1 /
16
"
BURNER
“CUT-OFF LEVEL”
AT CAST LINE
BURNER OFF
(35mm)
BURNER ON
1 3 /
8
"
BURNER
“CUT-OFF LEVEL”
AT CAST LINE
BURNER OFF
(35mm)
BURNER ON
1 3 /
8
"
MOTORIZED
VALVE
CLOSED
BURNER
OFF
BURNER
“CUT-OFF LEVEL”
AT CAST LINE
2 3 /
16
"
(56mm)
MOTORIZED
VALVE
CLOSED
MOTORIZED
VALVE
OPEN
(27mm)
1 1 /
16
"
Pump and Burner Switch Contact Ratings
Voltage Pilot Duty Only
120 VAC
345 VA
240 VAC
Switch Ratings
Burner Valve
120 VAC
345 VA 0 - 135 ohms @ 24 VAC
240 VAC
Series 93/193 and Series 94/194
Low Water Cut-Off/Pump Controllers
For Steam Boilers and Level Control Applications
Typical Applications:
– Primary or secondary pump controller/
low water fuel cut-off
for steam boilers
– Motorized valve controller
– Proportional valve controller
– Low water cut-off
– High water cut-off
– Alarm actuation
• 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, instal-
lation, and maintenance of plumbing, steam, and electrical equipment and/or systems in
accordance with all applicable codes and ordinances.
• To prevent serious burns, the boiler must be cooled to 80˚F (27˚C) and the pressure must be
0 psi (0 bar) before servicing.
• 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.
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 of
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 blow down, connect a drain pipe to the control
opening to avoid exposure to steam discharge.
• To prevent a fire, do not exceed the switch contact rating.
WAR NING
CAUT ION
! WARNING
Series 93 or Series 94 Series 193 or Series 194
MM-404J
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.
CAUTION:
A more frequent replacement interval may be necessary based on the condition 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.
Failure to follow this warning could cause property damage, personal inj ury or death.
•
!
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