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Mercoid Series 123/125 Cast Iron Chamber - Water Level Control

Heavy Duty, Cast Iron Chamber

Designed for boiler applications, the Model 123 is primarily used for low water cut-off or feed-water control. Other applications include condensate tanks and deaerators. A special snap action switch mechanism eliminates frequent operation due to surging water level. A transparent cover provides convenient visible operation of the switch. Features a flanged chamber for easy clean out and replacement of float or switch mechanism without removing the unit from piping. The 125 offers the same long lasting service with a direct action mercury switch movement that provides a close deadband where needed.

 
SPECIFICATIONS
Service: Compatible liquids. Cast iron is not for use with lethal or flammable substances either liquid or gaseous.
Wetted Materials: Body: cast iron. Float and Trim: 304 SS. Packing Gland: brass. Packing: carbon. Body Gasket: carbon.
Temperature Limit: 365°F (185°C).
Pressure Limit: 150 psig (10.34 bar).
Enclosure Rating: General purpose. Optional weatherproof.
Switch Type: SPDT snap switch or mercury switch. Optional DPDT or two stage.
Electrical Rating: Snap Switch: 15A @ 120/240/480 VAC, 0.5A @ 120 VDC resistive, 0.25A @ 240 VDC resistive. Mercury Switch: 4A @ 120 VAC/DC, 2A @ 240 VAC/DC.
Electrical Connections: Screw terminal.
Conduit Connection: 7/8" (22.23 mm) hole for 1/2" (12.7 mm) conduit.
Process Connections: 1" female NPT.
Mounting Orientation: Vertical.
Weight: 20 lb (9.1 kg).
Agency Approvals: UL and CSA (snap switch is not rated).
Deadband: Approximately 1-1/2" (38.1 mm).
Specific Gravity: 0.88 minimum.
Options: Manual reset.
 
POPULAR MODELS
Model Number Description Usually Ships
123-153 Water level control, cast iron chamber, SPDT mercury switch. Same Day
123-7000-153 Water level control, cast iron chamber, SPDT snap switch. Same Day
123-2 Water level control, cast iron chamber, SPST mercury switch, closes on increase. Same Day
123-3 Water level control, cast iron chamber, SPST mercury switch, opens on increase. Same Day
123-804 Water level control, cast iron chamber, DPDT (2 SPDT) mercury switches. 1-2 Weeks
125-4820 Water level control, cast iron chamber, SPST mercury switch, closes on decrease. 1-2 Weeks
125-4821 Water level control, cast iron chamber, SPST mercury switch, opens on decrease. 1-2 Weeks
 
MODEL CHART - SERIES 123/125
EXAMPLE
123
2
123-2 Liquid Level Control with SPST mercury switch closing on level increase, minimum specific gravity 0.88, cast iron body, general purpose case, switch rated at 10 amp 120VAC/DC, 5 amp 24 VAC/DC, pressure 150 psi (10 bar), maximum process temperature 365°F (185°C).    
CONSTRUCTION
123
 
Packing gland construction, cast iron chamber*, general purpose case, snap acting movement assembly. UL CSA
CIRCUIT
2
SPST, close on level increase, mercury switch, rated 10 amp 120 VAC/DC, 5 amp 240 VAC/DC, motor rating 1 hp 120 VAC, 3/4 hp 240 VAC, 1/3 hp 120/240 VDC.    
3
SPST, open on level increase, mercury switch, rated 10 amp 120 VAC/DC, 5 amp 240 VAC/DC, motor rating 1 hp 120 VAC, 3/4 hp 240 VAC, 1/3 hp 120/240 VDC.    
153
SPDT, one circuit closes as one circuit opens, mercury switch, rated 4 amp 120 VAC/DC, 2 amp 240 VAC/DC, common ground.    
156
SPDT, consisting of two SPST mercury switches, electrically independent, one circuit closes as one circuit opens, each switch rated 10 amp 120 VAC/DC, 5 amp 240 VAC/DC.    
804
DPDT, consisting of two SPDT mercury switches, each switch has common ground, two circuits close as two circuits open, each switch rated 4 amp 120VAC/DC, 2 amp 240 VAC/DC.    
7000-153
SPDT snap-action switch, rated 15 amp 120/240/480 VAC, 1/2 amp 120 VDC Rees., 1/4 amp 240 VDC res.    
OPTIONAL HOUSING  
 
WP Weatherproof adlet housing.    
EXAMPLE 125 4820   125-4820 Liquid Level Control with SPST mercury switch closing on level fall, minimum specific gravity 0.88, cast iron body, general purpose case, switch rated at 10 amp 120VAC/DC, 5 amp 240 VAC/DC, pressure rating 150 psi (10 bar), maximum process temperature 365°F (185°C).    
CONSTRUCTION 125     Packing gland construction, cast iron chamber*, general purpose case, direct acting movement assembly. UL CSA
CIRCUIT   4820   SPST mercury switch, close on level fall, rated 10 amp 120 VAC/DC, 5 amp 240 VAC/DC, motor rating 1 hp 120 VAC, 3/4 hp 240 VAC, 1/3 hp 120/240 VDC. UL CSA
  4821   SPST mercury switch, open on level fall, rated 10 amp 120 VAC/DC, 5 amp 240 VAC/DC, motor rating 1 hp 120 VAC, 3/4 hp 240 VAC, 1/3 hp 120/240 VDC. UL CSA
  4810   SPDT, one circuit closes as one circuit opens, mercury switch, rated 4 amp 120 VAC/DC, 2 amp 240 VAC/DC, common ground. UL CSA
  4815   SPDT, consisting of two SPST mercury switches, electrically independent, one circuit closes as one circuit opens, each switch rated 10 amp 120 VAC/DC, 5 amp 240 VAC/DC. UL CSA
  4806   DPDT, consisting of two SPDT mercury switches, each switch has common ground, two circuits close as two circuits open, each switch rated 4 amp 120VAC/DC, 2 amp 240 VAC/DC. UL CSA
 
 
 
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