Henry

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LIQUID MANAGEMENT
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LIQUID LEVEL SWITCHES
NPT Type
The function of a Liquid Level Switch is to detect and monitor liquid
level in a vessel.
Applications
Henry Technologies' Liquid Level Switches are designed for use in a variety
of refrigeration and industrial applications. Liquid Level Switches can be
installed in Liquid Receivers, Suction Line Accumulators, compressor
crankcases, or a variety of other applications, to detect and monitor fluid
levels.
Henry Technologies' Liquid Level Switches are suitable for use with
ammonia, HFC and HCFC refrigerants and their associated oils, as well as
other industrial fluids non-corrosive to steel and glass.
Main Features
ŸPatented optical sensor technology*
ŸNPT connection to liquid
Ÿ1/2” conduit connection for wiring
ŸHigh and Low Voltage models
ŸServiceable without refrigerant loss
ŸNEMA 4 and 4X approved
ŸReplacement parts available
Materials of Construction
The Level Switch Housing is made of plated steel with hermetically sealed
soda lime glass prism. The Level Switch is secured in the housing with a
plated steel retainer and sealed with a silicon O-ring.
Technical Specifications
Maximum working pressure = 1200 PSI (82.7 Bar)
Allowable operating temperature = -40°F to +200°F (-40°C to +93.3°C)
Power for Operation = 3.5 mA AC, 5.5 mA DC
Minimum Load = 2 mA (without bleed resistor)
Henry Technologies' Liquid Level Switches meet the requirements of UL 873
and UL 207 and are USR and CNR recognized by Underwriters Laboratories,
Inc.
Switch Inductive Rating = 36 VA Pilot Duty Rated
Additionally, Liquid Level Switches are CE marked in accordance with
PED.
Part No NPT
(inch)
Fig
No
Dimensions (inch)
A (hex) B
S-9400 Series 1/2 1 1-1/8 2.55
S-9400-1 Series 1 2 1-3/8 2.73
How it Works
The Liquid Level Switches use light reflecting from a conical glass prism as a
means of detecting the absence of a fluid at the level of the glass cone.
When no fluid covers the lower half of the cone, infrared light from the
module reflects from the mirror-like inner surface of the cone back to a light
detector signaling the electric module to switch. When fluid covers the lower
half of the glass cone, the light from the module passes into the fluid. This
absence of light is detected by the module which switches into the opposite
direction.
Installation - Notes
1. Liquid Level Switches must be installed horizontally. Switches cannot
be mounted at an angle or vertically.
2. When installed, no objects are to be within 2” of the glass prism.
3. Install Level Switches with a socket wrench to avoid glass cracking. An
open-end wrench should not be used.
4. The user must ensure the Liquid Level Switch is installed with
appropriate thread sealant for the application.
5. Wiring diagrams are included with the full instructions given in the
Product Instruction Sheet, included with each unit.
Part No Voltage Resistive Rating
(Amp)
Contacts with Liquid
Present Wire color Code Replacement
Module
S-9400 120VAC 50/60 Hz 0.5 Closed Yellow & White 2-044-012
S-9400-1 120VAC 50/60 Hz 0.5 Closed Yellow & White 2-044-012
S-9400A 120VAC 50/60 Hz 0.5 Open Yellow & White/Stripe 2-044-017
S-9400A-1 120VAC 50/60 Hz 0.5 Open Yellow & White/Stripe 2-044-017
S-9420 208/240VAC 50/60 Hz 0.25 Closed Red & White 2-044-015
S-9420-1 208/240VAC 50/60 Hz 0.25 Closed Red & White 2-044-015
S-9420A 208/240VAC 50/60 Hz 0.25 Open Red & White/Stripe 2-044-018
S-9420A-1 208/240VAC 50/60 Hz 0.25 Open Red & White/Stripe 2-044-018
S-9424 24 V AC/DC 0.5 Closed Orange & White 2-044-013
S-9424-1 24 V AC/DC 0.5 Closed Orange & White 2-044-013
S-9424A 24 V AC/DC 0.5 Open Orange & White/Stripe 2-044-020
S-9424A-1 24 V AC/DC 0.5 Open Orange & White/Stripe 2-044-020
ΠNPT Connection
 1/2” Conduit Connection
A
B
1
2
FIG 2
B
A
1
2
FIG 1
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