Rockwell Automation 871TM Inductive Proximity Sensor - Manual (Page 2)

CAUTION; Solid state devices can be susceptible to radio frequency (RF) interference, depending on the
frequency of the transmitting source. If RF transmitting equipment is to be used in the vicinity of the solid state
devices, thorough testing should be performed to assure that the transmitter operation is restricted to a safe
operating distance from the control equipment and wiring.
INSTALLATION INSTRUCTIONS
3 Sn
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
EFFECTS OF NEARBY METAL SURFACES
ЙЙЙЙЙЙ
Sensors embedded in metal
Shielded
Sensors not embedded in metal
Not shielded
Sn = rated operating distance d = diameter of sensing surface
SPACING BETWEEN SENSORS
Sensors embedded in metal
Shielded
d d d
Sensors not embedded in metal
Not shielded
2d d
d
d = diameter of sensing surface
WARNING: Do not let METAL objects that
are not to be sensed come within three
times the sensing distance of this device.
Unintended process activation may result
in a hazardous condition.
SENSING DISTANCE
CORRECTION FACTORS
Steel 1.0
Stainless Steel 0.9 to 1.0
Brass 0.3 to 0.5
Aluminum 0.1 to 0.4
Aluminum ≤ .012 thick 0.9 to 1.1
Copper 0.4 to 0.6
The standard target is a square of mild steel
(ST37), 1mm thick. The side of the square
is equal to the diameter of the sensor or
three times the sensing distance, whichever
is larger. Targets smaller than standard size
may shorten the sensing distance. Targets
larger than standard may lengthen the
sensing distance.
To determine the sensing distance for
materials other than the standard mild steel,
multiply the sensing distance by the factor
given below:
SERIES CONNECTED SWITCHES
PARALLEL CONNECTED SWITCHES
When connected in series, the operating
load voltage must be less than or equal to
the minimum supply voltage, minus the
voltage drops across the proximity switches
connected in series. The load will energize
when the connected outputs of all proximity
switches are energized.
To determine the maximum number of
switches for an application, the sum of the
maximum OFF-state currents of the
switches connected in parallel must be less
than the maximum OFF-state current of the
load device. The load will be energized when
the output of any proximity switch energizes.
NOTE: Parallel operation of switches does
not provide higher load current capability
and may generate a false pulse" under
certain conditions.
IMPORTANT: Save these instructions for
future use. For additional information and
proper operating guidance, refer to the
Allen-Bradley Proximity Catalog 871-1.2 or
the product data sheet 871TM-2.0
When installing side by side, the minimum spacing
distance should be maintained. When mounting face
to face, use two times the diameter.
Metals immediately opposite the sensing face should
be no closer than three times the rated operating
distance of the sensor.
ЙЙЙЙЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
ЙЙЙ
d d d
2d d
d
d
Metal free
zone
3 Sn
≥ 3d