Inductive and capacitive sensors - INFRA - #3

Inductive and Capacitive Sensor

GENERAL SPECIFICATIONS

1) Do not exceed the voltage limits printed on the product label. For DC sensors, use stable tension.

2) Do not connect the sensors power supply cables down-stream from other devices and make sure they are directly connected to the mains.

3) If the power supply source is a switching voltage regulator, connect the FG (Frame Ground) terminal to the ground.

4) Connect to the ground the FG (Frame Ground) terminal and all metallic parts of every industrial machinery or not if a sensor is used in it.

5) Do not use the sensors near electromagnetic or high frequency fields.

6) The cables of sensors must be separate from the power supply cables, from the engines cables, from the inverters cables, or from any other electromagnetic device because induction noise could cause malfunction or damage to the inductive sensors. Separate the wires of the sensor from the above indicated lines and then insert the wires into an earthed metal conduit.

As these sensors are effected by metal, the area close to the active surface should be free. This area can be of air, non-magnetic or non-conductive material. When sensors are installed side by side, the distance between two sensors should be 2D (D = sensor diameter).

Avoid over-tightening the fastening nuts in order not to damage the housing and to avoid breaking the internal circuit as a result.

Take particular care with the models which have a diameter less than 12 mm.

Sensitivity adjustment should be carried out when the sensor is installed in a definitive and stable position. Adjustment should be fixed in an intermediate position between minimum and maximum because, since air is a dielectric, a strong variation in humidity could cause inappropriate energising of the sensor (if adjustment is very fine).

The intervention range of the sensor depends on the type of material to be detected and its dimensions (see reduction factor table). The distance can vary depending on the temperature variation by about ± 10% in a range of -20 to +70°C.

To increase sensitivity, turn the trimmer clockwise, to decrease sensitivity, turn it anti-clockwise.

To gain access to the trimmer, remove the plastic protection screw located at the back of the sensor.

Earth terminal connection of metal conduit Sensor wire

7) After making all operations men-tioned in the above point 6, if inductive

interference exists, an adequate transient suppression filter must be used on the power supply line in proximity to the sensor.

8) When a large distance by the connection wires to the sensor has to

be covered, use conductors with a cross-section of at least 0.50 mm² and do not exceed the maximum distance of 100 m.

9) The output signal of a sensor cannot be used during the start up delay (not more than 300 mS).

10) Several sensors should not be connected in series, whereas several sensors can be connected in parallel.

1) For correct assembly and alignment, all the accessories supplied with the sensor must be used.

2) To regulate the sensitivity adjustment trimmer use a suitable screw-driver without exerting excessive force.

3) Do not turn too much fixing screws or nuts to avoid electrical or mechanical damages.

4) Mounting sensors side by side, leave an appropriate place between them to avoid mutual interference.

5) Do not pull the connection cable of the sensor. When the conditions of use result to be too hard (in places not protected from shocks or subjected to movements) use a protective sheath.

Sensitivity adjust.

0 18

0 30

MOVING DEVICE

fastening

6) Avoid continuous movements between the sensor and its cable and follow the instructions given in the drawing.

7) Protect the sensitive surface of the sensor from shocks, mechanical pressures to avoid irreparable damages.

8) Install the sensor being careful that metallic (or of any other material) shavings shall not settle on the sensitive part of the sensor.

9) Do not use the sensors in presence of organic or liquid solvents or of any kind of acid.

10) Do not use the sensors outdoors without an adequate protection.

11) Do not exceed the indicated temperature limits.

12) Do not subject the appliance to strong vibrations or to shocks which can damage the sensor or can harm its impermeability.

13) Although some ranges of INFRA proximity sensors are protected to IP67, this does not mean that our devices can be used to detect objects in water or in the rain.

The manufacturer is not liable for the improper use of the product. Any use and/or application which are not provided for by the instruction manuals must be previously and directly authorized by the same manufacturer. Shielded types

These sensors are not effected by the surrounding metal and therefore the unit can be embedded in it. In order to avoid reciprocal interfe-rance when more sensors are installed side by side, the minimum distance between two sensors must be D/2 (D = sensor diameter).

For assembly in contact with the metal surface, observe the following values:

Although some ranges of INFRA photoelectric sensors are protected to IP67, this does not mean that our devices can be used to detect objects in water or in the rain.

A stabilised source of voltage can be obtained using the table indicated beside. Use the following ways to dimension the components:

VAC = (V RMS transformer) = ⁽

" 1.41

(0.0053) x I OUT (value indicated in uF ) 2

C1 =

VL1 = VAC x 1.41 x 1.2

If "t" is bigger than 10 cm, add C4 beside the stabiliser C4 = 100 uF ; VL4 = VAC x 1.41 x 1.2 C2 = 220 uF ; VL2 = VOUT x 1.2 C3 = 0,1 uF ; VL3 = 63 V

Note: the regulator must provide adequate power dissipation as:

(VAC x 1.41) - VOUT I OUT max

Where IOUT max. is the maximum available (supplied) current

P DISS. =

Sensore

Metallo

74