Water Level Sensors & Relays 12 or 24 VDC for Off Grid Solar Pumps & Well Pumps

A recent Simple Pump solar submersible well pump alternative application for a low replenishment rate well sent me on a search for a standalone all low voltage water level sensors and relays with timer solution.  It took me hours of searching the Internet to find it because water level control manufacturers don't do much with low voltage.

The solution is two single sensor probes with the following specifications:

  • Sensors are made from Avesta 254 High Grade Stainless Steel Alloy

  • Probe Casing is made from uPVX Premium Quality Extruded Tube

  • The sensor cable is PVC/PVC single core made specifically for this application

  • The probe dimensions 32 mm diameter

  • A suspension mounting bracket is provided

  • The single core cable is 1.0 mm square in a 6.9 mm sheath

  • The cable resistance is 32 Ohms per mile

  • Operating environment temperature range is 32 to 149 F or 0 to 65 C

  • Standard cable lengths are 33 or 98 feet 10 or 30 meters

  • Longer cables are available on special order

In a typical installation one probe would be suspended above your pump at a safe low water level point to prevent the pump from running dry.  A second probe would be suspended above the first probe at an acceptable water recovery level point to restart the pump.  The relay also has adjustable timers for either or both probes if needed to prevent short cycling of the pump.

The relay specifications:

  • Probe Inputs:

    • Sensor voltage 10/12VAC Nominal

    • Sensor current 0.8mA max. (per sensor)

    • Sensitivity 1k, 4k, 20k, 80k

  • Relay Outputs:

    • 2 contact sets : 1 N/O & 1 C/O

    • Output delay 0, 2.5, 5, 10, 20, 40, 80, 160 seconds

    • Relay contact rating 250 VAC

    • 5A Resistive, 2A Inductive

  • Terminal size 2 x 13 AWG / 2.5mm2

  • Display LEDs: Power On Green, Pump On Red

  • Relay dimensions 2.7/8 H x 1.3/4 W x 4.1/2 D (Inches) 72 Hx45 Wx114 D (mm

  • Mounting DIN Rail or 2 x #6 Screws or 2 x M4 Screws

  • The relay enclosure is Makrolon (self-extinguishing)

  • Power Supply:

    • Supply Voltage DC 12 or 24VDC

    • Power Consumption 3 Watts max

  • Temperature tolerance: - 10 to + 600 C or +14 to + 1400 F

Alternate supply voltages are available in AC for 24, 110, 240, 415VAC - 50/60Hz

Other options are available including a relay with an alarm output circuit.

These heavy industrial grade components are a matched set designed to provide high reliability.  The probe warranty is 10 years.  The components are UL listed.

This is not an inexpensive solution but it is less costly than the time, effort and expense of retrieving and rebuilding or replacing a pump or pump motor damaged from running dry.

If you have questions or need assistance, we are ready to help.