Level Switch
Model L-21

Wide Differential Level Switch

The L-21 is a low cost, high performance level switch made from highly durable plastics. It features a variable liquid level differential and a single point pump up/pump down level control.

The L-21 Level Switch can be ordered with level differentials of 1, 2, 3 or 5 inches.  The L-21+ can be ordered with level differentials from 12 to 48 inches.  The L-21’s large differential provides immunity to nuisance switch tripping due to wave action and turbulence.  The large differential also provides very low cost single point pump-up/pump-down level control.  No latching relay needed!

Maintenance and checkout is easy using any standard multimeter.   Each unit comes with a detailed instruction manual and parts list.

Working Fluid Specific Gravity

0.7 minimum

Working Temp

200˚F (93˚C) Maximum

Working Pressure

250 psig (1.724 MPa)

Process Connection

1″ NPT

Electrical Switch

SPDT (single pole double throw) 15A

Enclosure

NEMA 6P / IP 67

Uses

Water Level Control in:

  • Cooling Towers
  • Plating Tanks
  • Washing Tanks
  • Reverse Osmosis
  • Fish Farms
  • Fountains & Pools
  • Aquariums

Models

L-21+ & L-21N (NORYL®)

WORKING PRESSURE: 250 psi max. continuous

WORKING TEMPERATURE: 180˚F max. continuous.

WETTED MATERIALS: Body, Float and Bushing: Noryl® (PPO) (10% glass fibers) screws + shaft: 316 stainless steel or Teflon®

L-21VCR (FORTRON®)

WORKING PRESSURE: 250 psi max. continuous

WORKING TEMPERATURE: 200˚F max. continuous.

WETTED MATERIALS: Body, Float and Bushing: Fortron®

(PPO) (40% glass fibers) screws + shaft: HASTELLOY® C

 

L21
Group
L-21N
L-21VCR

Specs

HYSTERESIS (Δ LIQUID LEVEL TO ACTIVATE/DEACTIVATE SWITCH)
≈ 5″ max. travel (N/VCR).

ELECTRICAL SWITCH CHARACTERISTICS
SPDT (single pole double throw) 15 A, 1/2 hp @ 125 or 250VAC .A @ 125VDC, .A @ 250VDC 4A @ 125VAC (Tungsten lamp load)

Note: Model L-21 employs magnetic coupling between float arm and switch body. Magnetic particles can accumulate on and around magnet housing which may affect proper operation. Please conduct appropriate fluid magnetic particle evaluation and operational tests prior to and during installation and use.

WORKING FLUID SPECIFIC GRAVITY
0.7 minimum

Diagram

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