43
Wiring Section 2-2
Connecting 2-Wire AC Sensors
A two-wire sensor cannot be connected directly to the AC input. To
connect a two-wire sensor, attach an external bleeder resistance in
the way shown below.
• Example: Connecting to a CPU Unit or Expansion I/O Unit
a) Use a resistance that satisfies both of the following
conditions.
b) Because of heat generation, use a resistor with at least the
following wattage.
Note Calculating the Bleeder Resistance
when Connecting an OMRON E2E-
X10Y 2-Wire AC Sensor
This calculations in this example
are based on an input voltage of
85 to 110 V AC.
The following values are from the
Sensor datasheet.
The Sensor's maximum leakage
current is 1.7 mA.
The minimum current when the
Sensor's OFF residual voltage is
L
R
N
I0 to I5
Two-wire
sensor
Internal
circuit
R1 (Ω) ≤
Max. OFF-voltage for AC input (25 VAC)
Sensor’s max. leakage current (A)
R2 (Ω) ≤
Voltage supplied to sensor (V)
Min. current for which the
sensor’s OFF residual voltage is
less than 25 V (A)
P (W) ≥
(
Voltage supplied
to sensor)
2
Resistance value
× 3 (allowance factor)
Output residual voltage
Load current
mA
Load residual
voltage
Load voltage VL (V)
At 100 V AC
E2E-X@Y@
ON
100 VAC
OFF
Z211-E1-03.book Page 43 Friday, November 21, 2008 10:38 AM
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