Coolant Level Alarm Switch Model S285


SKU: S85-1 Categories: ,


An active device which is designed to give an alarm signal if water/coolant based fluids falls below or rises above a present level. It will only signal after a 10 seconds delay in sensing the level to eliminate false alarms due to turbulence.

Containing a programmable microprocessor, the switch can offer one or two output pins which can sink to ground or supply a source voltage, or both.

Its tiny footprint with limited intrusion into the tank means a reduced risk of damage and a wide range of options and customization makes it suitable for most applications.
Product background:
The Level Alarm Switch S285 series was introduced to the market over 10 years ago and since its inception over half a million sensors have been supplied proving it as a very robust and reliable product. It has now become an industry standard and is specified worldwide by many leading engine manufacturers including Perkins, Cummins and Caterpillar.

Fluid Types:

Water based fluids compatible with Brass, PTFE and NBR rubber.

Electrical Rating:

    • Supply Voltage: 5 VDC or 7 – 35 VDC
    • Supply Current: 1.5mA + source output
    • Max. Load Current: 1.0A (sink) or 20mA (source)
    • Alarm Delay Time: 0 – 25 secs rising or falling (factory set)
    • Connection: 4 way Delphi Packard connector
    • Start-up Delay: 1 – 5 secs


  • Body: Brass
  • Probe: PTFE
  • Terminals: SAE CA210Brass, Tin Plated
  • Seals: NBR rubber
  • Connector: 30% Glass Filled Nylon 6
  • Thread sealant: Vibra-Seal 516