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Precautions for Correct Use title

The following conditions must be considered to understand the conditions of the application and location as well as the relation to control equipment.

Model Selection

Model Selection table

Design

Sensing Object Material

The sensing distance varies greatly depending on the material of the sensing object. Study the engineering data for the influence of sensing object material and size and select a distance with sufficient leeway.

In general, if the sensing object is a nonmagnetic metal (for example, aluminum),the sensing distance decreases.

Example: E2-X10D[]

Sensing Object Material diagram

Size of Sensing Object

In general, if the object is smaller than the standard sensing object, the sensing distance decreases.

Design the setup for an object size that is the same or greater than the standard sensing object size from the graphs showing the sensing object size and sensing distance.

When the size of the standard sensing object is the same or less than the size of the standard sensing object,select a sensing distance with sufficient leeway.

Size of Sensing Object diagram

Thickness of Sensing Object

The thickness of ferrous metals (iron, nickel, etc.) must be 1 mm or greater.

For non-magnetic metal, a sensing distance equivalent to a magnetic body can be obtained when the coating thickness is 0.01 mm or less. With pulse-response models (e.g., E2V), however, the characteristics may vary. Be sure to check the catalog information for the relevant model.
When the coating is extremely thin and is not conductive, such as a vacuum deposited film, detection is not possible.

Thickness of Sensing Object diagram

Influence of Plating If the sensing object is plated, the sensing distance will change (see the table below).

Effect of Plating (Typical)(Reference values: Percent of non-plated sensing distance)

Thickness and base material of platingSteelBrass
No plating100100
Zn 5 to 15 μm90 to 12095 to 105
Cd 5 to 15 μm100 to 11095 to 105
Ag 5 to 15 μm60 to 9085 to 100
Cu 10 to 20 μm70 to 9595 to 105
Cu 5 to 15 μm-95 to 105
Cu (5 to 10 μm) + Ni (10 to 20 μm)70 to 95-
Cu (5 to 10 μm) + Ni (10 μm) + Cr (0.3 μm)70 to 95-

Mutual Interference

Mutual interference refers to a state where a Sensor is affected by magnetism (or static capacitance) from an adjacent Sensor and the output is unstable.

One means of avoiding interference when mounting Proximity Sensors close together is to alternate Sensors with different frequencies. The model tables indicate whether different frequencies are available. Please refer to the tables.

When Proximity Sensors with the same frequency are mounted together in a line or face-to-face, they must be separated by a minimum distance. For details, refer to Mutual Interference in the Safety Precautions for individual Sensors.

Power Reset Time

A Sensor is ready for detection within 100 ms after turning ON the power. If the load and Sensor are connected to separate power supplies, design the system so that the Sensor power turns ON first.

Turning OFF the Power

An output pulse may be generated when the power is turned OFF, so design the system so that the load or load line power turns OFF first.

Influence of Surrounding Metal

The existence of a metal object other than the sensing object near the sensing surface of the Proximity Sensor will affect detection performance,increase the apparent operating distance, degrade temperature characteristics, and cause reset failures. For details, refer to the influence of surrounding metal table in Safety Precautions for individual Sensors.
Particularly the distance m that separates a metal surface that faces the Sensor's sensing surface will influence performance, such as shortening the sensing distance.
The values in the table are for the nuts provided with the Sensors.Changing the nut material will change the influence of the surrounding metal.

Power Transformers

Be sure to use an insulated transformer for a DC power supply. Do not use an auto-transformer (single-coil transformer).

Precautions for AC 2-Wire/DC 2-Wire Sensors

Surge Protection

Although the Proximity Sensor has a surge absorption circuit, if there is a device (motor, welder, etc.) that causes large surges near the Proximity Sensor, insert a surge absorber near the source of the surges.

Influence of Leakage Current

Even when the Proximity Sensor is OFF, a small amount of current runs through the circuit as leakage current.For this reason, a small current may remain in the load (residual voltage in the load) and cause load reset failures. Verify that this voltage is lower than the load reset voltage (the leakage current is less than the load reset current) before using the Sensor.

Using an Electronic Device as the Load for an AC 2-Wire Sensor

When using an electronic device, such as a Timer, some types of devices use AC half-wave rectification. When a Proximity Sensor is connected to a device using AC half-wave rectification, only AC halfwave power will be supplied to the Sensor. This will cause the Sensor operation to be unstable. Also, do not use a Proximity Sensor to turn the power supply ON and OFF for electronic devices that use DC halfwave rectification. In such a case, use a relay to turn the power supply ON and OFF, and check the system for operating stability after connecting it.

Examples of Timers that Use AC Half-wave Rectification Timers: H3Y, H3YN, H3RN, H3CA-8, RD2P, and H3CR (-A, -A8, -AP,-F, -G)

Countermeasures for Leakage Current (Examples)

AC 2-Wire Sensors

Connect a bleeder resistor to bypass the leakage current flowing in the load so that the current flowing through the load is less than the load reset current.

When using an AC 2-Wire Sensor, connect a bleeder resistor so that the Proximity Sensor current is at least 10 mA, and the residual load voltage when the Proximity Sensor is OFF is less than the load reset voltage.

AC 2-Wire Sensors diagram

Calculate the bleeder resistance and allowable power using the following equation.

The bleeder resistance and allowable power equation

P: Watts of bleeder resistance (the actual number of watts used should be several times this number)

I : Load current (mA)

It is recommend that leeway be included in the actual values used.For 100 VAC, use 10 kΩ or less and 3 W (5 W) or higher, and for 200 VAC, use 20 kΩ or less and 10 W (20 W) or higher. If the effects of heat generation are a problem, use the number of watts in parentheses ( ) or higher.

DC 2-Wire Sensors

Connect a bleeder resistor to bypass the leakage current flowing in the load, and design the load current so that (leakage current) × (load input impedance) < reset voltage.

DC 2-Wire Sensors diagram

Calculate the bleeder resistance and allowable power using the following equation.

The bleeder resistance and allowable power equation

P : Watts of bleeder resistance (the actual number of watts used should be several times this number)

iR : Leakage current of Proximity Sensor (mA)

iOFF : Load reset current (mA)

It is recommend that leeway be included in the actual values used.For 12 VDC, use 15 kΩ or less and 450 mW or higher, and for 24 VDC, use 30 kΩ or less and 0.1 W or higher.

Loads with Large Inrush Current

Loads, such as lamps or motors, that cause a large inrush current* will weaken or damage the switching element. In this situation, use a relay.

* E2K, TL-N[]Y: 1 A or higher

Mounting

Mounting the Sensor

When mounting a Sensor, do not tap it with a hammer or otherwise subject it to excessive shock. This will weaken water resistance and may damage the Sensor. If the Sensor is being secured with bolts,observe the allowable tightening torque. Some models require the use of toothed washers.For details, refer to the mounting precautions in Precautions for Correct Use in individual product information.

Mounting/Removing Using DIN Track
(Example for E2CY)

Mounting

(1)Insert the front of the Sensor into the special Mounting Bracket (included) or DIN Track.

(2)Press the rear of the Sensor into the special Mounting Bracket or DIN Track.

Mounting1 diagram

When mounting the side of the Sensor using the special Mounting Bracket, first secure the Amplifier Unit to the special Mounting Bracket, and then mount the special Mounting Bracket with M3 screws and flat washers with a diameter of 6 mm maximum.

Mounting1 diagram

Removing

While pressing the Amplifier Unit in the direction of (3), lift the fiber plug in the direction of (4) for easy removal without a screwdriver.

Removing diagram

Set Distance

The sensing distance may vary due to fluctuations in temperature and voltage. When mounting the Sensor, it is recommend that installation be based on the set distance.

Wiring Considerations

AND/OR Connections for Proximity Sensors

Note:When AND/OR connections are used with Proximity Sensors, the effects of erroneous pulses or leakage current may prevent use. Verify that there are no problems before use.

1. DC 2-Wire

1.-(1) AND (series connection)

DC 2-Wire AND Connection diagram

Keep the number of connected Sensors (N) within the range of the following equation.

The_number_of_connected_Sensors_equation

It is possible, however, that the indicators may not light correctly and error pulses (of approximately 1 ms) may be generated because the rated power supply voltage and current are not supplied to individual Proximity Sensors.Verify that this is not a problem before operation.

1.-(2) OR (parallel connection)

DC 2-Wire OR Connection diagram

Keep the number of connected Sensors (N) within the range of the following equation.

The number of connected Sensors equation

Example: When an MY (24-VDC) Relay is used as the load, the maximum number of Sensors that can be connected is 4.

2. AC 2-wire

2.-(1) AND (series connection)

AC 2-Wire AND Connection diagram

TL-NY, TL-MY, E2K-[]MY[], TL-T[]Y
The above Proximity Sensors cannot be used in a series connection. If needed, connect through relays.

E2E-X[]Y
For the above Proximity Sensors, the voltage VL that can be applied to the load when ON is VL = VS - (Output residual voltage × Number of Sensors), for both 100 VAC and 200 VAC.
The load will not operate unless VL is higher than the load operating voltage.This must be verified before use.
When using two or more Sensors in series with an AND circuit, the limit is three Sensors. (Be careful of the VS value in the diagram at left.)

2.-(2) OR (parallel connection)

AC_2-Wire_OR_Connection_diagram

In general it is not possible to use two or more Proximity Sensors in parallel with an OR circuit.

A parallel connection can be used if A and B will not be operated simultaneously and there is no need to hold the load. The leakage current, however,will be n times the value for each Sensor and reset failures will frequently occur.
("n" is the number of Proximity Sensors.)

If A and B will be operated simultaneously and the load is held, a parallel connection is not possible.If A and B operate simultaneously and the load is held, the voltages of both A and B will fall to about 10 V when A turns ON, and the load current will flow through A causing random operation. When the sensing object approaches B,the voltage of both terminals of B is too low at 10 V and the switching element of B will not operate. When A turns OFF again, the voltages of both A and B rise to the power supply voltage and B is finally able to turn ON.

During this period, there are times when A and B both turn OFF (approximately 10 ms) and the loads are momentarily restored. In cases where the load is to be held in this way, use a relay as shown in the diagram at left.

Note:When AND/OR connections are used with Proximity Sensors, the effects of erroneous pulses or leakage current may prevent use. Verify that there are no problems before use.

3. DC 3-wire

3.-(1) AND (series connection)

DC 3-Wire AND Connection diagram

Keep the number of connected Sensors (N) within the range of the following equation.

The number of connected Sensors equation

Note:When an AND circuit is connected, the operation of Proximity Sensor B causes power to be supplied to Proximity Sensor A, and thus erroneous pulses (approximately 1 ms) may be generated in A when the power is turned ON. For this reason, take care when the load has a high response speed because malfunction may result.

3.-(2) OR (parallel connection)

DC_3-Wire_OR_Connection_diagram

For Sensors with a current output, a minimum of three OR connections is possible.Whether or not four or more connections is possible depends on the model.

Extending Cable Length

The cable of a Built-in Amplifier Sensor can be extended to a maximum length of 200 m with each of the standard cables (excluding some models).For Separate Amplifier Sensors (E2C-EDA, E2C, E2J, E2CY), refer to the specific precautions for individual products.

Bending the Cable

If you need to bend the cable, we recommend a bend radius that is at least 3 times the outer diameter of the cable (with the exception of coaxial and shielded cables).

Cable Tensile Strength

In general, do not subject the cable to a tension greater than that indicated in the following table.

Cable diameterTensile strength
Less than 4 mm30 N max.
4 mm min.50 N max.

Note: Do not subject a shielded cable or coaxial cable to tension.

Separating High-voltage Lines

Using Metal Conduits If a power line is to be located near the Proximity Sensor cable, use a separate metal conduit to prevent malfunction or damage. (Same for DC models.)

Example of Connection with S3D2 Sensor Controller

DC 2-Wire Sensors

Using the S3D2 Sensor Controller

Operation can be reversed with the signal input switch on the S3D2.

DC 2-Wire Sensors Using the S3D2 Sensor Controller_diagram

Connecting to a Relay Load

DC 2-Wire Sensors Connecting to a Relay Load_diagram

Note:DC 2-Wire Sensors have a residual voltage of 3 V. Check the operating voltage of the relay before use.The residual voltage of the E2E-XD-M1J-T is 5 V.

DC 3-Wire Sensors

Operation can be reversed with the signal input switch on the S3D2.

DC 3-Wire Sensors diagram

Operating Environment

Water Resistance

Do not use the Sensor in water, rain, or outdoors.

Ambient Conditions

Do not use the Sensor in the following environments.
Doing so may cause malfunction or failure of the Sensor.

1. To maintain operational reliability and service life, use the Sensor only within the specified temperature range and do not use it outdoors.

2. The Sensor has a water resistant structure, however, attaching a cover to prevent direct contact with water will help improve reliability and prolong product life.

3. Avoid using the Sensor where there are chemical vapors,especially strong alkalis or acids (nitric acid, chromic acid, or hot concentrated sulfuric acid).

At low temperatures (0°C or less), the vinyl cable will harden and the wires may break if the cable is bent. Do not bend a Standard or Robot Cable at low temperature.

Maintenance and inspection

Periodic Inspection

To ensure long-term stable operation of the Proximity Sensor, inspect for the following on a regular basis. Conduct these inspections also for control devices.

1. Shifting, loosening, or deformation of the sensing object and Proximity Sensor mounting

2. Loosening, bad contact, or wire breakage in the wiring and connections

3. Adherence or accumulation of metal powder

4. Abnormal operating temperature or ambient conditions

5. Abnormal indicator flashing (on setting indicator types)

Disassembly and Repair

Do not under any circumstances attempt to disassemble or repair the product.

Quick Failure Check

You can conveniently check for failures by connecting the E39-VA Handy Checker to check the operation of the Sensor.