Phares Electronics ZS09P Zero Speed Switch Sensor

Phares Electronics ZS09P Zero Speed Switch Sensor for Conveyors and More

The Phares Electronics ZS09P Zero Speed Switch Sensor reacts quickly if your conveyor or other industrial machinery stops abruptly.  Stop conveyor “domino” effect promptly before things get out of hand.  Our zero speed switch sensors detect both magnetic and high iron content targets, such as a gear tooth, bolt head, key stock, etc.

Phares ZS09P Zero Speed Switch Sensor Industrial Machine Speed Monitoring

Compact, self contained sensor. Switches up to 5 amps. No additional control box needed.

  • Magnetic zero speed switch sensor for conveyors and more
  • Stop conveyor “domino” effect
  • Over speed, under speed or zero speed detection
  • Compact all-in-one zero speed switch sensor
  • Isolated 5 amp relay contacts
  • Contact arrangements: N.O./N.C. (form ‘C’), N.O. only, or N.C. only
  • LED indicators for instant visual confirmation
  • Precision trim pot for accurate relay set point adjustment

This little sensor is big enough to help protect your expensive machinery from major malfunctions and minor mishaps.

You will not be disappointed with its performance!

Get all of your questions answered at 727-444-0406.


Download or view as PDF:



The Phares Electronics ZS09P Zero Speed Switch Sensor is a rugged, all-in-one device that combines sensor and relay, for use in over speed, under speed, or zero speed monitoring. Install on augers, bucket elevators, conveyors, exhaust fans, grinders, turbines, windmills and many other applications where shaft speed monitoring is needed. It has an adjustable set point for precise, accurate speed measurement, and reacts quickly if your machine stops abruptly.

The Phares ZS09P Zero Speed Switch Sensor looks like a prox switch, but incorporates intelligent speed sensing circuitry not found in simple on/off devices. When machine shaft speed reaches the set point, the Phares ZS09P relay output changes state. It remains in this state until under speed or zero speed condition occurs.

Phares ZS09P Zero Speed Switches have isolated relay contacts making it easy to incorporate into new or existing systems, or to replace obsolete zero speed switch sensors.  Get your questions answered promptly at 727-444-0406.


 Phares ZS09P Zero Speed Switch Sensor Part Numbers

Part Number

Relay Output

Relay Contact Rating

Input Voltage

ZS09P1-120N.O./N.C. (Form 'C')5 Amps120 VAC
ZS09P2-120N.O.5 Amps120 VAC
ZS09P3-120N.C.5 Amps120 VAC
ZS09P1-DN.O./N.C. (Form 'C')5 Amps6-24 VDC
ZS09P2-DN.O.5 Amps6-24 VDC
ZS09P3-DN.C.5 Amps6-24 VDC



Power Requirements:
Part No. ZS09P-120: 120VAC, 20mA, 50/60Hz
Part No. ZS09P-D: 6-24VDC, 69mA

Relay Output: (specify when ordering)
SPDT Form ‘C’ dry relay contact (Normally Open/Closed)
SPST Normally Open
SPST Normally Closed

Contact ratings:
5A, 240VAC
5A, 30VDC
Vibration resistance (function) NO/NC contact >15/5g
Shock resistance (destruction) >100g

Operating Frequency:
Hall Effect and Inductive (Geartooth): 0.02Hz – 10kHz
Hall Effect Only: 0.02Hz – 25kHz

Sensing Distance (Gap):
1/16″ to 1/8″ using Geartooth Wheel, Bolt Head, Key Stock, etc.
1/8″ to 1/4″ using Magnetic Disk.
1/8″ to 5/8″ using Magnet or Magnetic Disk.
(Magnetic target sensing distance based on Phares Electronics Magnetic Disks and magnet types).

Minimum Geartooth Sizes:
1/8″ geartooth length, width, depth and gap.

Geartooth Material:
High ferrous (iron) content.

Operating Temperature:
-40°F to 140°F

6 oz.

4 ft., 6 conductor, 22 AWG, unshielded
(Custom cable lengths available.)

Dimensions (in inches)

Phares ZS09P Zero Speed Switch Sensor Dimensions

Figure 1. Dimensions of Phares ZS09P Zero Speed Switch Sensor

Wiring Connections

Phares ZS09 Zero Speed Switch Sensor Wiring Connections

Figure 2. Phares Zero Speed Switch Sensor wiring connections.

There are LED indicators for Relay and Pulse. Relay LED illuminates when the Relay is energized. Pulse LED illuminates whenever the ZS09P detects a target. The set point is adjusted via trim pot.


Sensor Targets suitable for Phares Zero Speed Switches

The Phares ZS09P Zero Speed Switch sensor requires a target suitable for sensing in order to measure speed.  Sensor targets are sold separately.

Suitable targets are:
Magnetic Disk
Geartooth Wheel
Split Coupling
Bolt head or key stock


Sensor Target Illustrations

Phares ZS09P Zero Speed Switch Sensor and Phares Magnetic Disk Axial Orientation Phares ZS09P Zero Speed Switch Sensor and Phares Magnetic Disk Radial Orientation

Figures 3 and 4.  Phares Zero Speed Switch Systems consisting of Zero Speed Switch Sensor and Phares Magnetic Zero Speed Switch Sensor Targets.

Geartooth Wheel with Phares ZS09P Zero Speed Switch Sensor Radial OrientationFigure 5.  Phares Zero Speed Switch Sensor and geartooth sensor target.