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Brass vertical liquid level switch with cylindrical Buna-N float and 3/4 inch NPT fitting

Madison

Madison M4168-1 SPST Drum Liquid Level Switch 240VAC

SKU CH-M6MT-J51WM

A brass-stem SPST float switch closes on rising liquid, rated 240 VAC and 150 psi for vertical tank mounting

  • Product typeLight Switch
  • Closes circuit as liquid rises with SPST contact form
  • Handles up to 240 VAC and 0.28 A for reliable switching
  • Brass stem and Buna-N float resist corrosion in harsh fluids
  • Rated to 150 psi pressure and 221 °F operating temperature
  • Compact 2.94 in overall length fits tight tank openings

Madison M4168-1 SPST Drum Switch

The Madison M4168-1 is a single-pole single-throw liquid level switch designed for vertical mounting in open tanks. It uses a Buna-N float on a brass stem to detect rising liquid levels and close the circuit. The brass body carries a 3/4 inch NPT tank connection and a 3/4 inch conduit entry. It is rated for 240 VAC maximum voltage and a 30 VA rating.

Replaces manual tank monitoring

This switch automates pump or valve control by closing on rise, removing the need for visual checks. The upgrade is worth it when a reliable 150 psi pressure rating and 221 degrees F maximum operating temperature are required for the application. It suits systems needing a compact 2.94 inch overall length and a 1.25 inch float travel. The 0.28 A maximum current rating limits it to low-power control circuits.

Fits 3/4 inch NPT tank openings

The brass stem and body resist corrosion in compatible fluids, while the Buna-N float handles a range of liquids. Vertical mounting frees up horizontal tank space and simplifies installation in tight fittings. The SPST contact form provides a simple on signal for relays or controllers. No external power supply is needed for the switching action itself.

How it compares

Measured against everything we stock in Electrical Switches & Dimmers, at today’s prices. Recalculated every night.

Price $94.99
Pricier than about 74% of the 791 comparable items (median $39.99).

Specifications

Product
Brand nameMadison
Product typeLight Switch

Questions about this item

What tank connection size and mounting orientation does the M4168-1 require?

The switch mounts vertically in an open tank with a 3/4 in NPT connection and a 3/4 in conduit size.

How do I wire the SPST contact correctly for close-on-rise operation?

Wire the single-pole single-throw contact so the circuit closes when the liquid lifts the float; the VA rating is 30 at up to 240 VAC and 0.28 A.

Which parts contact the liquid and what temperature limit applies?

The Buna-N float and brass stem sit in the fluid, with a maximum operating temperature of 221 °F and a pressure limit of 150 psi.

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