TM 5-3895-374-24-2
MAXIGARD
A122-92
A5000 & A5000NF ZERO SPEED SWITCH
Installation and Operating Instructions
Introduction
The "Maxigard" A5000 and A5000NF Zero Speed Switch is designed to monitor the rotation of any moving shaft.
It will signal any starting or stopping.
Principle of Operation
The A5000 Zero Speed Switches operate on the principle of a magnet passing in front of a switch sensor. As the
shaft rotates, pulses are generated and picked up by the sensor. These pulses are sent to the switch circuitry and activate
the On/Off portion of the circuit (N.O.). This solid state contact (triac) may be used for control, indicating, and/or alarm. If
the monitored shaft stops rotating, pulses will stop being generated, causing the triac switch to turn off.
Components
The A5000 and A5000NF switch package includes: magnet disc, mounting bracket and circuitry with self
contained enclosure.
INSTALLATION AND MOUNTING INSTRUCTIONS
I.
Magnet Disc
A.
The end of the shaft to be monitored must be square to prevent excessive disc wobble
B.
Center drill and tap the shaft end. (suggest #21 drill and #10-32NF tap). Mount the magnet disc, label side
out; use Loctite to keep the disc tight on shaft (see Fig. 1 A)
II.
Magnet Wrap (optional)
A.
Separate the two halves of the wrap by loosening the alien head cap screws
B.
Place both halves around the shaft
C.
Tighten the cap screws, making sure the wrap is square to the shaft
D.
There will be a slight gap between the two halves after tightening.
This gap will not affect the generated signal (see Fig. 1 B)
III.
Mounting the Switch
A.
Position the motion switch so that the sensor is centered directly in front of the magnets in the disc or
optional wrap (see Fig. 1 A or 1B)
B.
The gap setting between the sensor and magnet should be approximately 1/4".
C.
See Section VI for gap adjustment instruction
page 3 - 738
