Float Type Level Switch
The workhorse of point-level detection — a magnetic float flips a sealed reed or micro-switch at the set level, for alarms, pump control and interlocks.
Technical Data
| Switching principle | Magnetic float actuating sealed reed switches on the stem |
|---|---|
| Mounting | Top (vertical stem) or side (horizontal pivot) |
| Set points | Single std.; multiple points on one stem optional |
| Contacts | 2 × SPST-NO std. — 1.5 A, 50 W/VA, max. 200 V DC / 250 V AC |
| Process connection | 2" BSP std. (ELSy: ½"–1¼" BSP); flanged optional |
| Stem length | Up to 2500 mm (thread included) |
| Float / wetted materials | 304 stainless steel std.; 316 opt.; PU float on ELSy |
| Working temperature | Max. 125 °C |
| Electrical connection | Terminal, cable or socket housing — relay output in housing available |
Selection Guide
Vertical stem with one switching level.
Best forAlarms · simple controlSeveral reed points on one stem — high, low and in between.
Best forPump + alarm packagesDatasheet & Drawings
GA, hook-up and wiring drawings are prepared per order — supplied with your quotation for approval.
EN 10204 3.1 material certificates are supplied with your shipment.
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Frequently Asked Questions
How does a float type level switch work?
A float carrying a magnet rises and falls with the liquid. At the set point the magnet actuates a sealed reed switch or a micro-switch, changing an electrical contact that can drive an alarm, pump or interlock.
What is the difference between a reed switch and a micro-switch type?
A reed switch is a sealed glass contact operated without physical contact by the float's magnet, giving long, wear-free life. A micro-switch is a snap-action mechanical contact, chosen where a higher contact rating is needed.
Should I choose top or side mounting?
Top mounting suits narrow tanks and multi-point detection, with several switching levels on one stem. Side mounting suits tanks where top access is limited and a single set point is required.
Can one switch give more than one set point?
Yes. A top-mounted stem can carry several reed switches at different heights, so a single fitting can provide, for example, a high-level alarm and a low-level pump cut-out.
Is it affected by foam, bubbles or conductivity?
No. Because switching is magnetic and driven by buoyancy, the float switch is unaffected by foaming, bubbles, vapour or the electrical properties of the liquid.
Which housing and connection options are available?
Terminal, cable or socket electrical connections, with the relay output available inside the housing. Process connection is 2" BSP as standard, with flanged versions on request.
Engineered to order. Delivered worldwide.
Send your duty conditions — size, pressure, temperature, medium and connections — and our engineers return a drawing, material selection and lead time.
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