Inductive Proximity Switch

Industrial inductive proximity switch:

principle of operation

inductive:

inductive proximity switch products high frequency altering field at the sensing face. When any metallic material enters in the sensing zone of the switch, the field gets disturbed. A sensitive detector circuit senses this change which is further processed by amplifier circuit to produce output signal.

object:

sailent features:

1) repeat accuracy : 0. 02 mm

2) hysteresis : 3-10 %

3) grade of protection : ip67, for block type : ip55

4) enclosure : metallic (nickel – chrome plated brass) / stainless steel / plastic

5) led indication : provided 

6) ambient : 60 º c max

7) switching frequency : ac switch : 5 hz

dc switch : m 8 & m 12 : 5 khz

above m 18 : 1 khz

dc switches ac switches

a) supply voltage : 10-30 v dc max ripple :10% 90-230 v ac, 50 hz max surge current : 1 a

b) protection : short circuit and wrong polarity, (except size m8) protection against transients and voltage spikes

c) length : 65mm / 50mm 80 mm

d) logic available : no / nc / changeover no / nc

e) load current : 200 ma / 500 ma (on request) 150 ma, 500 ma (on request), (min 30 ma)

three / four wire dc switches: series: is 3d/ 4d:

these are three / four wire switches (+ ve, -ve and output) working on 10-30 v dc, and directly drives dc relay. Theses switches are compatible with plc modules because of its insignificant leakage current (50 µ a max) dc switches are divided into two categories according to load connection

1. load connected between supply wire and output wire : (npn)

2. load connected between ground wire and output wire: (pnp)

entire range is available with no or nc logic. Special switches with change-over logic are also available. Dc switches are protected against overload, short circuit and wrong polarity connection. Special switches with high operating frequency are available for applications of speed sensing. Special protection incorporated within the switch against back emf from inductive load like relay.

Inductive proximity switch (2 wire ac switch):

two  ac proximity switches: type: is 2a :

a c switches operated on  90-230 v ac and directly drive load like contactor or solenoid coil. Low voltage drop of 6 v across the switch makes it suitable to connect even two switches in series. Special protection against spurious signals is incorporated.

supply voltage                     :, 90-230 vac

load current                        : 150-200 ma suitable to drive siemens size ‘o’ connector or equivalent load. Special switches with load current of

                                                  of 500 ma are also available in two wire version. Load  current for three wire proximity switch is 500 ma

operated frequency           : 5 hz

supply on response           :

delay                                     : 100 m sec

max surge current              : 1 a max (t  20m sec / f, 1hz)

noise immunity                   : ac proximity switches are protected against damage due to transient voltage peaks. Noise immunity for 4 kv / 20

                                                  micro sec

ac switches are not protected against short circuit of load. Hence care should be taken for proper wiring.  

Inductive proximity switch (2 wire dc switch)

namur sensor / two wire dc proximity switches: type: is 2d:

these are two wire current operated switches. The switch is designed for installation in hazardous areas. Switch draws current less than 3 to 4 ma in absence of metal and 1 ma in presence of metal. The switch is suitable for operation in hazardous area group classification i, ii a, ii b, ii c, as per is 5780-1980 temperature class t4 (certified by cmrs dhanbad), when fed through an intrinsically safe controller on zener barrier. This amplifier unit detects change in current and further processes to give output signal. Amplifier unit along with power supply and output relay fitted in separate enclosure with ip30 or ip55 grade of protection. These switches are compatible with internationally available intrinsically safe controller.

Squre Enclosure And Limit Switch Housing:

NAMUR SENSOR / Two Wire DC Proximity Switches: Type: IS 2D:

These are two wire current operated switches. The switch is designed for installation in hazardous areas. Switch draws current less than 3 to 4 mA in absence of metal and 1 mA in presence of metal. The switch is suitable for operation in hazardous area Group classification I, II A, II B, II C, as per IS 5780-1980 temperature class T4 (certified by CMRS Dhanbad), when fed through an intrinsically safe controller on zener barrier. This amplifier unit detects change in current and further processes to give output signal. Amplifier unit along with power supply and output relay fitted in separate enclosure with IP30 or IP55 grade of protection. These switches are compatible with internationally available intrinsically safe controller.