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Magnetically Adjustable Vibration Threshold (MAVT™)
Magnetically Adjustable Vibration Threshold (MAVT
™) is a Smart Switch selectable feature via USB
programming. This unique capability allows the alarm threshold value to be determined and set automatically by
the Smart Switch based on the actual vibration level being measured by it. This convenient feature permits any
machine to be protected by a vibration switch within seconds without knowing anything about its vibration levels.
The Smart Switch has no accessible mechanical adjustments (ie. screw pots or DIP switches) that are found on
other style electronic vibration switches. However, when the MAVT
™ option is selected, the hermetically-sealed
switch becomes adjustable through magnetic actuation. By touching a specified location on the housing with a
strong permanent magnet for 2 seconds, an internal microprocessor is actuated that initiates the test sequence.
Note: The magnet clip (Model 080A214) is a supplied accessory when the Smart Switch is ordered from the
factory with the optional 600A29 USB Switch Programmer Kit.
Figure 38
– Magnet Clip
MAVT
™
Procedure
B
e absolutely sure you do not have the switch connected to the machine’s trip circuit during this procedure as the
trip relay is activated several times during the procedure and will cause the machine to shut down and turn on
several times. This could cause damage to your machinery.
1. Mount the Smart Switch on the machine that the switch will monitor. Be sure that the machine is
operating in a steady state condition. If it is not operating, turn the machine on and allow enough time for
the vibration level to normalize before going to the next step.
2. Connect the switch to the power supply using an appropriate cable. Since the Smart Switch operates off
universal power, any power supply that outputs 24-240 VDC or 24-240 VAC, 50/60 Hz will work. A
simple 24V power supply/signal conditioner (Model 480C02) will also work well and has the added
advantage of visually indicating when the calibration process has been completed via its built-in meter.
Allow 30 seconds for the switch to power up.
3. Touch the permanent magnet to the target on the side of the switch for approximately 2 seconds to
initiate the process.
4. The alarm threshold calibration process takes approximately 30 seconds. (The amount of time needed
varies based on the difference between the previous and new alarm threshold values.) During this
process, the unit will measure the average vibration amplitude, set the alarm threshold value to two times
this average value and store this value in a non-volatile memory. The relay contacts open and close
repeatedly during this process.
5. Disconnect the Smart Switch from the power supply.
6. The switch can now be permanently installed on the machine for protection.
Summary of Contents for IMI SENSORS EX686B77
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