McDonnell & Miller MM 286 Series 1575 Low Water Cut-Off - Manual

Series 1575
Low Water Cut-Off/Pump Controller
For Steam Boilers and Other Level Control Applications
FEATURES
Probe Chamber:
• Cast Iron Body
• Sight Glass Tappings
• Gage Cock Tappings
• Stainless Steel Probes
• NEMA 4X Electrical Enclosure
• 250 psi Maximum Working Pressure
Probe Chamber
Electronic Control Unit
McDonnell & Miller
Installation & Maintenance
Instructions
MM-286
• 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 bu r n s , the boiler must be cooled to 80˚F (27˚C) and the pressure must be
0 psi (0 bar) before serv i c i n g .
• 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 cut-offs should be dismantled,
inspected, cleaned, and checked for proper calibration and performance.
• To prevent serious personal injury from steam bl ow dow n , connect a drain pipe to the contro l
opening to avoid exposure to steam discharge.
• To prevent a fire, do not use this low water cut-off to switch currents over 16A, 1 Hp at
120 VAC or 8A, 1 Hp at 240 VAC, unless a starter or relay is used in conjunction with it.
Failure to follow this warning could cause property damage, personal injury or death.
WARNING