ENT
SA420
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VAR RATE
Description:
Electro-Sensor’s SA420 Signal Conditioner provides an analog signal
directly proportional to the speed of a monitored shaft. The 0-10 VDC
and 4-20 mA outputs can be sent to a chart recorder, digital display, PLC,
loop controller, drive speed controller, or other control or monitoring
devices. The wide voltage range and wave shape flexibility of the
SA420’s sensor input circuitry allow it to translate signals from Hall-
Effect Sensors, proximity switches, magnetic sensors, and a wide variety
of other pulse generator devices into analog outputs.
Sensor Installation:
The standard sensor is supplied with a mounting bracket and two jam
nuts. The explosion-proof sensor is supplied with a slotted mounting
bracket. Sensors should be installed so the centerline of the magnets
pass in front of the center of the sensor as the disc or wrap rotates. When
using the pulser disc, the center of the magnetized area of the disc,
shown as Dimension B in figures 1 and 3, is 1-3/4 inches from the center
hole of the disc. The gap distance between the sensor and the disc or
wrap, Dimension A In the diagrams, is 1/4-inch ±1/8 inch. To achieve
the proper gap distance, adjust the jam nuts holding the standard sensor
in the mounting bracket, or adjust the position of the explosion-proof
sensor using the slots on its mounting bracket.
Pulser Disc:
The end of the shaft to be monitored must be center drilled to a depth of
1/2-inch with a No. 21 drill and tapped for 10-32UNF. After applying
Loctite™ or a similar adhesive on the threads to keep the pulser disc
tight, the pulser disc should be attached, decal side out, with the supplied
10-32UNF machine screw and lock washer.
Pulser Wrap (optional):
Pulser Wraps are custom manufactured to fit the shaft they will be
mounted on. When the wrap is shipped, four Allen-head cap screws hold
the two halves of the wrap together. These screws must be removed so
that the wrap is in two halves. Place the halves around the shaft, reinsert
the screws and torque them to 5 foot-pounds max.
A
B
Figure 1: Standard Sensor with 255 Pulser Disc
A
A
Figure 2: Standard Sensor with optional Pulser Wrap
B
A
Figure 3: Explosionproof Sensor with 255 Pulser Disc
A
A
Figure 4: Explosionproof Sensor with Pulser Wrap
SA420 Signal Conditioner
6111 Blue Circle Drive
Minnetonka, MN 55343
Phone: 952.930.0100
Fax: 952.930.0130
ISO 9001:2015 Certified
Free Catalog and Application Assistance
1.800.328.6170
Visit Us Online
www.electro-sensors.com
990-001700 Revision I
