The Electronic Speed Switch is a switch who sense the speed of rotating part & monitor (shows) any change in speed within certain speed range which already decided. And thus we can have a control over whole system where this switch is installed.

To overcome the damages due to variation in speed. Some time due to this (variation in speed) the quality or dimensions can be differ from the standard one. Big breakdown may occurs, motor get damaged, the operator of the system may get injury. To avoid all these things we have to use the speed switch. We can use this arrangement at variety of industrial drives in material handling & processing industries, such as conveyors, crusher, Agitators, Bucket elevator, fans, Drive chains and similar rotating machinery. By adding some developments we can use this switch with other many systems.

The sensing probe of this switch is non-contact type either inductive (or capacitive) i. e. actually without touching the rotating part of the machine this can sense the speed and the speed of rotating part which can rotates in either directions. Also as there is no rotating part & mechanical part in probe there is no maintenance probe and it can be use anywhere in industry, as its IP 67 no need of perfect align the sensed signal can transmit at any long dist. (500 Mtr.)

When a metallic body (here flag) cuts the magnetic field (Here due to sensing probe electromagnet) which is radiated by the probe is get damped giving corresponding output pulses. These are then goes to monitoring unit & the further action takes place.

Speed or motion of the rotating machine is sensed by the non-contact inductive type sensing probe. The probe is installed with its sensing face in close vicinity of the rotating part (flags) at suitable place. Metallic places of suitable dimensions are to be mounted on the rotating part. When flag passes across the face of probe, frontally radiated electromagnetic field of the probe is get clamped giving rise to corresponding o/p pulses. These pulses are then led the monitoring unit via inter connecting cables. The sensing probe can be mounted at the maximum distance of 500 meter from the monitoring unit. A LED located at rear side indicates the visual indication of sensing of flag.

This switch consists of two main parts as monitoring unit & sensing probe. Monitoring unit consist of the control circuit & sensing probe. Monitoring unit consist of the control circuit & sensing probe consist of the sensing unit which sense the speed of rotating part of machine.

The monitoring unit consists of the digital circulatory to give the response to signal received by sensing probe. This unit is provided with the setting knobs for step less setting of speed/bypass time. It also carries LEDs and 7 segment display to show the supply & relay status. Suitable terminals to accept up to 2.5 mm sq. cables are provided. This unit is available in variety of enclosure which are suitable for projection or flush mounting. Also different protection grades can be provided. On the name plate (or on front panel) all general specifications are provided.

This can be mounted with both projection & flush style of mounting. Also the whole unit monitoring & sensing probe both are available in tabular from with flush type of mounting.

These are LEDs provided on the unit which shows the supply & relay states, similarly digital displays are also available where we can see the preset time & speed range & for setting the time (TD, NTD, NITD etc) & speed a step less knob is provided on dial marking is provided which shows the position of the knob.

Analog i. e. LEDs are provided to show supply & relay status & the knobs position shows the selected time delay & speed limit while when there is digital display we can see all setting on display directly by pressing a switch.

Here the type of switch & its different ratting are provided also the setting knobs with step less & smooth working to set the time & speed. Supply & relay status also indicated by different colored LEDs for external connectors at terminal there we stick a diagram.

For this purpose we have plastic / sheet metal, Robust cast Aluminum, CA materials are available to fulfill the conditions of different protection grades, with other material we may not get these much standard result. Also the properties of these material are good.

We provide following protection grade

IP 30:- In this protection grade we have to protect our equipment (switch) against contact with live or moving parts inside the enclosure by tools, wires or such objects thickness greater than 2.5 mm.

IP 55:- In this protection grade we protect switch against harmful deposits of dust. The ingress of dust is not totally prevented but dust can not enter in an amount sufficient OK to interfere with satisfactory operation of the equipment enclosed. And also water projected by a nozzle from any direction under started conditions shall have no harmful effect.

IP 65:- In this protection grade we provide complete protection grade against contact with live or moving parts inside the enclosure. Protection against ingress of dust. And also protection against water jets under stated conditions.
Also there is a flameproof protection grade which can withstand up to high temp. And this grade has CMRS certificate (Central Mining Research Station)

Relevent IS No. These above protection grade are from IS : 2147, & = by

INDIAN STANDARD ITSTITUTION.

For the external connection we have provided the switch with different terminals as IP 00 mouled block, Elmex CST 4, specialstud type. The maximum voltage & current carring capacity (ratting) of the terminals can be varied according to external equipment (system) or to fulfill the protection grades conditions.

This can be seen in the diagram Provided.

It is a just like eye of the switch which sense the speed (see) of rotational motion system & gives the corresponding o/p signal.

When this probe is provided with the proper signal (supply voltage)it starts working it radiat the electromagnetic field in front of it's face (sensing) & when this radiateel field cut by metallic body (flag) it gives rise to corresponding output pulse which further goes to monitoring unit i.e. in short it working is to sense the speed/motion of the rotating machine. Protection grade for sensing probe — IP-67

We stated just above that it sence the speed,but for sensing speed this probe should keep within sensing distance which is different for different sizes. Diagram (Normal & Effective sensing distance)

These are available in tabular threaded metallic shapes & sizes can be change but the standard probe is M-30 type. And on request other standard sizes can be provided.

Same as monitoring unit projection or flush mounting style is available but here other style of mounting can provided.

It's sensing distance,supply voltage,type,current voltage ratings etc.

The probe is enclosed in a metallic/plastic enclosure with tubular threaded type. A Special cast Aluminium protective enclosure can be provided on request. Probes in Plastic block.

To sense the speed to probe the electromagnetic field radiateel by probe should be Interrupted by metallic body (electrically concluctive) & this body is known as a Flag.
The minimum & maximum size of flag is shown on the drawing sheet.

Supply voltage- 24V/110V/240V ±15% AC/DC
Power consumption — 5 VA max.
Speed ranges- These are six as,
1-10/10-100/100-1000/5-50/50-500/500-5000
speed setting accuracy with ±5%
Actuation differential — Less than 5% of set value
Visual indication — Red LED for supply ON
Green LED for relay ON
O/P contact ratting — 6A resistive at 240 VAC
Ambient temp. — 60 Deg. C max.
No. of flags — As per described.

TD:— Built in initial bypass time delay
NTD:— Built in nuisance tripping delay
NITD:—Combined nuisance + initial delay
AD, DD:—An log, digital display (respectively)
S:—Selector switch with multi range unit

The basic types of switches — RM 2210:—Unit with only display
RM 2211:—Under speed monitor
RM 2212:—Over speed monitor
RM 2213:—Combined over + under speed
RM 2214:—Under speed monitor with probe to sense speed of belt directly
RM 2215:—Under speed with relay operation for sequential starting of belt.
RM 2216:—Slip monitor

For sensing the speed of the conveyor we have to use the switch RM 2214.Similarly we can use switch at different places with slightly modifications.

In projection type of mounting of probe the electromagnetic field has the spread area around the plastic cap as shown & in flush mounting as the plastic cap is covered by the enclosure material we will not get the spread electromagnetic field as shown. And hence we will get more sensing distance with projection type of at mounting while with flush we won't

There are two types of it as 1 NO + 1 NC & 2 NO+ 2 NC with required ratings. These contacts ( i.e. terminals) are of 6 A resistive at 240 VAC. As in many cases these terminals are connected to the starter of the motor at