Electro-Sensors SG1000A Manual

SG1000A general description

The SG1000A is a SlideGate Monitor with a 4-20 mA output.
The SG1000A is a rugged, medium cost encoder-based
monitoring device that enables the end-user to very accurately
monitor a slide-gate's position, allowing very accurate blending
operations. The SG1000A has two modes: calibration mode,
and normal operating mode. A simple calibration procedure
teaches (programs) the SG1000A the fully-closed (0% open)
and fully-open (100% open) gate positions. Once programmed,
the SG1000A outputs a 4 mA DC signal when the gate is in the
fully-closed position, and outputs a 20 mA DC signal when the
gate is in the fully-open position. Any gate position between
fully-closed and fully-open, is represented by the output signal
being proportionally between 4 and 20 mA.

Physical Appearance and Installation Overview

Figure 1 is the front-view of the SG1000A, showing the encoder-
output-shaft.
Cable
The SG1000A attaches to the slide-gate's 'rack and pinion'
shaft, or similar rotating mechanical component, using an "end-
of-shaft" mounting method. See Figure 2. The SG1000A's
encoder-shaft-end screws into a single 3/8-inch diameter hole, to
a depth of 0.625 inch, having 3/8" – 16 UNC-2B threads.
Even though the SG1000A is mounted to the process shaft via
the "end-of-shaft" mounting method, installation of flexible
conduit and of the optional stabilizer bracket is recommended,
which allows the SG1000A to "float" along with any wobble
of the process's shaft while still preventing the SG1000A from
rotating along with that shaft (see Fig. 2).
Note: The stabilizer bracket's U-bolt is slightly oversized
to provide about 1/8" of slack between it and the
SG1000A. The U-bolt's slack prevents it from
rigidly clamping to the SG1000A's conduit port.
SG1000
U-Bolt
with slack
Flexible
conduit
6111 Blue Circle Drive
Minnetonka, MN 55343
Phone: 952.930.0100
Fax: 952.930.0130
ISO 9001:2000 Certified
SG1000A SlideGate Monitor
Encoder-Shaft
3/8"-16 UNC-2A threads
Figure 1:
Process Shaft
Stabilizer bracket
(use is optional)
Structural Framework
Figure 2:

Electrical connections

The SG1000A's electrical cable has three wires, plus a shield-
wire. Connect as follows: (See Figure 3):
Red
(+)
Requires
User Installed
Class 2 Isolated
+24Vdc
-
Black
Power Supply ( )
• Connect the shield wire to the earth ground.
• Connect the black wire to the power-supply (-) terminal.
• Connect the red wire to the power-supply (+24 Vdc)
terminal.
• Connect the clear wire to a resistive load of 250 Ω to
500 Ω, (usually this load is internal to a PLC, etc.).
Note: The clear wire is the 4-20 mA DC output line.
The other side of the 250 Ω to 500 Ω load must be
connected to the power-supply (-) terminal.
• See Figure 4 below for related information.

Calibration Procedure

Calibration consists of teaching the SG1000A the encoder
values for the fully-closed (0% open) and fully-open (100%
open) positions. The eight calibration steps are as follows (once
the user is familiar with the calibration procedure they need only
follow the underlined portions as a quick calibration guide):
1) Remove (twist CCW) the back-end-cover from the
SG1000A.
This provides access to the edge of the SG1000A's printed
circuit board, namely the direction switch SW1 (the slide
switch), and the calibration switch SW2 (the push-button
switch). See Figure 4 for locations of these switches.
CCW
SW2
R8
R7
TB1
Ground
Screw
Free Catalog and Application Assistance
SG1000
Ammeter
(optional)
+ -
Clear 4-20mA
PLC, Etc.
4-20mA
Shield
250 to 500
ohm load
Figure 3:
CW
CW(OFF) CCW(ON)
SW1
SW1 Detail
Red
Clear
Black
Shield
Figure 4:
1.800.328.6170
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990-002400 Revision I