APG FLX Series Installation Manual

Thank You
Thanks for purchasing a FLX series multi-point stem-mounted float switch from us! We appreciate
your business and your trust. Please take a moment to familiarize yourself with the product and this
manual before installation. If you have any questions, at any time, don't hesitate to call us at 888-
525-7300.
 NOTE: Scan the QR code to the right to see the full
user manual on your tablet or smartphone. Or visit
www.apgsensors.com/support to find it on our website.
Table of Contents
1. Description 5. Mounting and Installation
Instructions
2. How To Read Your Label
6. Wire Color Diagrams and
3. Warranty
Table
4. Dimensions
7. Removal Instructions
Description
1
The FLX contains up to seven reed switches in a 1/2 inch diameter stainless steel stem and
permanent magnets in the floats. As each float rises or falls with the level of the liquid, the magnet
inside the float acts on the corresponding reed switch inside the stem to provide SPST switching
action. The FLX carries explosion proof and non-incendive hazardous location approvals.
How To Read Your Label
2
Each label comes with a full model number, a part number, and a serial number. The model
number for the FLX will look something like this:
 SAMPLE:
FLX-4T2-A-1-B-21.00
The model number correlates with all the configurable options and tells you exactly what you have.
Compare the model number to the options on the datasheet to identify your exact configuration.
You can also call us with the model, part, or the serial number, and we can help you.
You'll also find all hazardous certification information on the label.
Warranty
3
This product is covered by APG's warranty to be free from defects in material and workmanship
under normal use and service of the product for 24 months. For a full explanation of our Warranty,
please visit https://www.apgsensors.com/about-us/terms-conditions. Contact Technical Support to
receive a Return Material Authorization before shipping your product back.
Scan the QR code below to read the full explanation of our Warranty on your tablet or smartphone.
Dimensions
4
4.375"
[111 mm]
4.375"
[111 mm]
Stem Ø
0.54"
14 mm
Float
Minimum
3.0"
Float Stop
[76 mm]

IMPORTANT: Your FLX MUST be installed according to drawing
9003281 (FLX Hazardous Location Mounting) to meet listed
approvals. Faulty installation will invalidate all safety approvals and
ratings.

IMPORTANT: The switch points on an FLX CANNOT be moved,
changed, or adjusted.
8. General Care
9. Repair Information
10. Hazardous Location Wiring
FLX Dimensions
4.375"
[111 mm]
4.375"
[111 mm]
Stem Ø
0.54"
Minimum
14 mm
2.0"
[51 mm]
Stem Length
Float
Minimum
Float Stop
2.0"
[51 mm]
FLX Stem-Mounted Float Switches
Installation Guide
For FLX Series
APG
Automation Products Group, Inc.
1025 W 1700 N Logan, UT 84321
www.apgsensors.com | phone: 888-525-7300 | email: sales@apgsensors.com
Mounting and Installation Instructions
5
Mounting Instructions:
• Flange Mounting: Provide the compatible mating flange on the tank and install using a
suitable gasket.
• Plug Mounting: Provide the compatible female boss on the tank and install the FLX with a
suitable gasket, O-ring, or thread tape.
Installation Notes:
• Do not locate the FLX series sensor near inlets/outlets.
• If there is surface wave action, then use a time-delay relay or stilling tube. If a stilling tube is
used, drill vent holes in the tube and use a spacer to assure the float has free travel inside the
tube (See Figure 5.1).
• The FLX can be mounted up to 30° from vertical.
Inflow

DANGER: Do not remove the housing cover until the atmosphere
is determined safe, and the power supply is turned off.
Electrical Installation Instructions:
• Install conduit and/or cable with necessary seal(s) per Drawing 9003281.
• Remove the housing cover.
• Check the Wire Color Diagrams and Table in section 6 before making any connections.
• Connect the wire(s) for your system to the appropriate terminal for each switch.
• Replace the housing cover.
• For inductive loads or high-voltage/high-current resistive loads, provide circuit protection for
switch(es) (See Figure 5.2). See Specifications on the data sheet or user manual for switch
ratings. Circuit protection must be located in non-hazardous areas.
Protecting Circuit Using Diode
Stem Length
R
Inflow
Stilling
Tube
Spacer
Figure 5.1
Protecting Circuit Using Varistor
Figure 5.2
Part # 200852
Doc # 9006502 Rev A
30° 30°
30°
Protecting Circuit Using CR
E
L
R
C
2
C = I /10 (uF)
E
R = Approx.
10 x I (I + 50/E)