Zero Speed Switch

Zero Speed Switch / Electronic Speed Switch / Monitor / Indicator

Now a days in material handling plants under/Over speed monitor is one of the essential control and safety device.

Application

Electronic Speed Monitor is used to monitor speed of conveyors, crushers, rolling mills, agitators, mixers, stirrers, screw conveyors, and other industrial machinery. This device actuates relay contacts at preset speed. Using these contacts desired control action such as zero speed protection / under speed protection/ over speed protection can be achieved.

Advantages :

  • It Senses speed by non – contact way. Hence no moving parts.
  • No wear and tears of rollers or misalignment of couplings. Easy speed setting.
  • Built-in initial bypass time delay arrangement.
  • Speed setting possible from 1 RPM to 5000 RPM in optional ranges.
  • The totally enclosed sensor works in the presence of dust, dirt water, oil & chemicals.
  • Direction sensing and speed monitoring of various locations from a single point is possible.
  • Intrinsically Safe Sensors and speed switches with Flameproof Enclosures are available for use in Hazardous area.

Operation:

The basic principle of speed monitor is comparison of pulses received from sensor with standard pulses. The unit consists of two parts : CONTROL UNIT and “SENSOR PROBE”. The sensor is to be installed with its sensing face in close proximity of rotating object. On this object, flags are to be fixed. The sensor products strong electromagnetic waves, which get disturbed by the flags, giving rise to corresponding pulses. These pulses are fed to the control unit where they are compared with standard pulses to sense the speed.

Output :

The control unit incorporates an output relay. This relay will operate at preset speed giving 2C/O contacts of 5 Amp 240 VAC resistive.

Initial Time Delay & Nuisance Delay :

Initial time delay facility to allow the rotating mechanism to attend the desired speed is provided. Standard delay is 0-30sec. Nuisance delay allows the system to delayed the trip action for few seconds as it may recover the speed.

Enclosure :

The sensor is epoxy potted and housed in metallic/ plastic tube. Control unit is enclosed cast AL / DMC enclosure.

Common Specification :

Sensor Probe

Totally enclosed, Inductive Type

Enclosure : Ni – Cr plated Brass enclosure, M 30 size with two check nuts (Refer group 4 of ordering proforma for other options)

Control Unit :

  • Enclosure : Field mounting IP65, Cast AL/Din Rail IP30 / Flame Proof (Refer group 2 of ordering proforma)
  • Output : 2 C/O relay contact, Rating 5Amp resistive at 230V AC with Led indication for supply ON, Sensor ON and Relay ON

Electronic Speed Switch / Zero Under Speed Switch :

Series ESW

The model is provided with the potentiometric setting. Suitable speed range is to be selected from six optional speed ranges 1 – 10, 10 – 100. 5 – 50, 50 – 500, 100 – 1000 and 500 – 5000 RPM. It also has a special optional facility to multiply speed range X 10 & X 100. Easy speed setting by the potentiometer, with supply ON ‘Relay ON’ and ‘SENSOR LED’ indication.

Models

  • Speed Switch : Din Rail mounting, IP 30 panel mounting enclosure, potentiometric setting, type ESW – D
  • Speed Switch : Weatherproof, field mounting, IP65 enclosure, potentiometric setting, type ESW – F
  • Speed Switch : Weatherproof, field mounting IP65 enclosure, DMC Enclosure potentiometric setting, type ESW – M
  • Speed Switch : Flame – proof enclosure for use in hazardous area with intrinsically safe sensor and control circuit, type ESW – L

Micro Controller Based, Speed Indicator Monitor – Tachometer Series ESW M

Features

Micro Controller based circuitry packed with customer friendly features.

  • Selectable number of flags. Enter number of flags which are available at site, Speed Monitor will get automatically calibrated for these flags
  • Digital Display
  • Adjustable trip delay
  • Settable hysteresis
  • Special models for combined under over speed monitoring duty
  • Special models with RS 232 / RS 485 retransmission facility

Digital Tachometer Series : ESW – D

It receives input from Transducer ( like proximity switch ) or analog input ( from transmitter ) and indicate speed in RPM, MPM or any other unit. Rotational/linear speed indication is possible. The unit is enclosed in panel mounting ( cutout 92 X 92 ) or dust proof, field mounting or flame proof enclosure.

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