FTS20 Float Level Switch Overview

FTS20 is a float level switch used for liquid level limit detection, featuring a cylindrical float design that can be installed through a G1 thread. Its microswitch is a double-throw type with a contact capacity of 250VAC/150VDC, suitable for various industrial applications.

The float body is made of PP (polypropylene), which has good chemical corrosion resistance. Depending on the application environment, CSM, PUR, or PVC cables can be selected, with standard cable lengths of 20m or 5m.

Spare Parts Order Numbers and Technical Parameters

The table below lists commonly used spare part order numbers and their key parameters for the FTS20 series float level switches, facilitating quick selection and procurement.

Order Number Description Output Type Explosion-proof Certification Cable Material Cable Length
71035522 Float Level Switch FTS20 Microswitch Double Throw None CSM 20m
52010124 Float Level Switch FTS20 Microswitch Double Throw None CSM 5m
71035521 Float Level Switch FTS20 Microswitch Double Throw None PUR 20m
52010123 Float Level Switch FTS20 Microswitch Double Throw None PUR 5m
71035520 Float Level Switch FTS20 Microswitch Double Throw None PVC 20m
52010122 Float Level Switch FTS20 Microswitch Double Throw None PVC 5m
71035518 Float Level Switch FTS20 2-wire NAMUR ATEX II 2G EEx ia IIB T5 CSM 20m
52010121 Float Level Switch FTS20 2-wire NAMUR ATEX II 2G EEx ia IIB T5 CSM 5m
52010120 Float Level Switch FTS20 2-wire NAMUR ATEX II 2G EEx ia IIB T5 PUR 5m
71035516 Float Level Switch FTS20 2-wire NAMUR ATEX II 2G EEx ia IIB T5 PVC 20m
52010119 Float Level Switch FTS20 2-wire NAMUR ATEX II 2G EEx ia IIB T5 PVC 5m

How to Select FTS20 Spare Parts

When selecting, it is important to confirm the following three factors to ensure the spare parts fully match the on-site application.

1. Output Signal Type

  • Microswitch Double Throw: Suitable for non-explosion-proof areas, can directly drive relays or PLC inputs.
  • 2-wire NAMUR: Requires an isolation amplifier, suitable for explosion-proof applications, compliant with EN60947-5-6 standard.

2. Explosion-proof Certification Requirements

If the application environment contains flammable or explosive gases, a NAMUR type with ATEX II 2G EEx ia IIB T5 certification must be selected. This certification indicates that the device can be used in Zone 1 and Zone 2 hazardous areas, with gas group IIB and temperature class T5.

3. Cable Material and Length

The cable material directly affects chemical corrosion resistance and mechanical strength. Please select according to the characteristics of the measured liquid:

  • CSM: Resistant to acids and bases, suitable for chemical liquids.
  • PUR: Resistant to fuel and oil, suitable for oil products and fuels.
  • PVC: Suitable for water and wastewater treatment.

Cable lengths are available in 5m and 20m specifications, which can be selected according to the on-site installation distance.

Installation and Usage Precautions

  1. Before installation, confirm that the process connection is a G1 thread and that the float can pass through freely.
  2. The float body is made of PP material; avoid use in strongly oxidizing acids or high-temperature environments (recommended temperature not exceeding 80°C).
  3. The NAMUR type must be paired with an isolation amplifier to ensure the intrinsic safety loop is complete.
  4. The cable should avoid excessive stretching or abrasion, and leave slack when securing.
  5. Regularly check whether the float operates flexibly to prevent foreign objects from jamming.

Frequently Asked Questions

Q1: What liquids can the FTS20 measure?

It is suitable for water, wastewater, acids, bases, fuel, oils, and other liquids, depending on the cable material and float compatibility.

Q2: What is the difference between the NAMUR type and the microswitch type?

The NAMUR type outputs a low-current signal and requires an isolation amplifier, used in explosion-proof areas; the microswitch type directly outputs a switching signal, used in non-explosion-proof areas.

Q3: Are the spare part order numbers valid long-term?

The order numbers listed in this article are based on the current product catalog. It is recommended to confirm the latest status with the supplier before purchasing.