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Factory Direct Upgraded Replacement Displacement Type Water Level Switch "G-Series" (Robertshaw)

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Station Diagrams

SL-400 G Series

Blower Time Delay Fan Control:


Factory Direct Upgraded Replacement Displacement Type Water Level Switch "G-Series"(Robertshaw)

Similar to SL-400 except displacers are made of impervious graphite, and there are three switching stations, each with a single mercury switch.

SL-400 G Series

Displacer type level switches, Model SL-400-G are top mounted and use impervious graphite displacers in the control of liquid level under conditions of turbulence or agitation. Wide adjustable differentials on three mercury type switching stations are obtained by setting position of displacers along stainless steel cable.

Model SL-400 LevelAc level switches use "heavier-than-liquid" displacers which sink below the surface of the liquid under control. Spring suspension balances the normal displacer weight, and as the liquid level rises around the displacer, it is buoyed up by a force equal to the weight of the liquid displaced. The apparent weight loss allows the spring to move the internal armature into the externally mounted switch's magnetic field to produce switch operation.

Mercury Switching Station - A glass capsule containing the mercury and switch contacts is mounted on a pivoted arm. A magnetic armature moves up and down inside a non-magnetic sealing tube following movement of the float caused by changing liquid level in the float chamber. As the armature enters the field of the Alnico V magnet mounted on the opposite end of the pivoted arm, magnetic attraction causes the magnet to approach the sealing tube and tilt the mercury capsule to make or break an electrical circuit.

Specifications :

Mounting Top mounted

Screwed Connection 3" - 8 NPT

Mounting Flanges

Size 3", 4" standard

Material: Steel - 150 lb. and 300 lb. ANSI

Cast Iron - 125 lb. and 250 lb. ANSI

Type 304 and 316 Stainless Steel - 150 lb. ANSI

Note: Other flange sizes, ratings and materials available on order.

Displacers Four , Impervious Graphite

Cable 316 Stainless Steel, 10 ft

Clamps 316 Stainless Steel standard.

Magnetic Armature 430-F corrosion resistant steel.

Support Spring Stainless Steel

Support Spring Housing

Brass is standard, Stainless Steel is available.

Spring Retainer Stainless Steel is standard.

Snap Ring Stainless Steel only.

Specific Gravity Ranges 0.7 to 1.25

Temperatures 300
• F (Ambient around displacers and around switch housing)

NOTE: Since specific gravity and temperature affect calibration, these values must be specified on order.

Pressure Brass Bias Spring Housing : Vacuum to 300 psi @ 300

316 Stainless Steel Bias Spring Housing: 1000 psi @ 100
• F ; 800 psi @ 300
• F.

Differential Adjustable Variable within cable length, 10 ft. standard.

Switch Housing :

Explosion-proof Heavy cast aluminum base and cover. With drain; NEMA 7A, B, C, D; 8C, D; 9E, F, G; 10; 12; 13.

Vapor-proof Similar to Explosion-proof except with "O" ring seal at base and no drain, NEMA 5; 7C, D; 9E, F, G; 10; 12; 13.

NOTE - Explosion-proof and Vapor-proof housings are U/L and CSA Approved as float-operated motor control unit for use in hazardous locations.

Switch Stations :

Number: Three

Type: Mercury only, each equipped with one only SPDT mercury switch.

Switch Characterstics:

Mercury Switch Hermetically sealed. SPDT mercury capsule switches are standard. Anti-vibration mercury capsules are optional.

* Anti-vibration switch rating

4 amp @ 120 VAC; 3amp @ 240 VAC

4 amp @ 120 VDC; 3amp @ 240 VDC

Internal Wiring 20 gauge copper (105 strands of No. 40 wire for extreme flexbility) insulated with silicone rubber.

Terminal Board Bakelite barrier terminal strip. Terminal position marked.

Switch Frame Pivot arms and wiring shields are heavy gauge brass. For maximum corrosion resistance, frame may be zinc plated on special order.

Magnet Alnico-V, stabilized.

Pivots Low friction "dog" type. Stainless steel pivot screws.

Replaces Part Numbers:

SL400G Series
SL-400 G Series
SL-400G Series
SL400 G Series


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