Electrical Contactors Manufacturer & Supplier in India | BCH Electric Limited

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• Welcome you all..
• in the training session on
• Contactors

BCH ELECTRIC LTD
www.bchindia.com
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• Contactors

• Contents
• Basics Standards
• Selection Applications
• Our Range Specification

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DUROS contactors
Contactor basics

• What is a Contactor?
• A contactor is an Electro-mechanical switching
  device which is used for switching a power
  circuit
• It is similar to a relay, except with higher
  current ratings.
• It is a remotely operated device
• High mechanical electrical life.
• Construction
• A contactor consists of 4 subsystems
• Electromagnet system
• Fixed moving magnets system
• Arc quenching system
• Housing

High Service Reliability
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DUROS contactors
Contactor basics
Basic working principle of a contactor Electrical
Energy ? Mechanical Energy It converts electrical
energy into mechanical energy in a the presence
of magnetic field. When the supply is given to
the coil, it gets energized and become an
electromagnet, which attracts the moving core
towards fixed core. During starting, coil draws
more current than the holding period as moving
core has to overcome the initial inertia. The
ratio of starting (Pick up) and holding (Hold)
currents are approximately 10. I pick up / I hold
on 10
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DUROS contactors
Contactor basics
Basic Terminology 1. Contact Bounce When the
moving contact just touches the fixed contact, it
experiences bounce. Bounce is detrimental to the
life of contacts, as every bounce will generate
an arc and reduce the contact material. 2. Magnet
gap This is the distance between moving core and
fixed core in OFF condition. 3. Contact gap This
is the distance between fixed contact moving
contact when the contactor is in OFF condition.
4. Over travel of moving contact (also called
wipe) This is the distance between moving core
fixed core when the fixed and moving contacts
just touches during contactor closing
operation. Over Travel Magnet Gap - Contact Gap

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DUROS contactors
Contactor basics
5. Arc Suppression It is a method for
extinguishing electrical arcs between the
contacts. Arc suppression is necessary to ensure
worker safety and prolong contact life. It is
done with the help of Arc Chutes. 6. Pick-up VA
Its a burden of the contactor coil on the aux
supply to MAKE the contacts. It is generally 10
times the Hold-on VA. It should always be kept
low. 7. Hold-on VA Its a burden of the
contactor coil on the aux supply to HOLD the
contacts. It should be always kept low. 8.
Rated Making Capacity It is the value of current
stated by the manufacturer which the equipment
can satisfactorily make under specified making
conditions (it is generally 10 times the rated
current) 9. Rated Breaking Capacity It is the
value of current stated by the manufacturer which
the equipment can satisfactorily break under
specified breaking conditions (it is generally 8
times the rated current)
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DUROS contactors
Contactor basics
IEC Standards Utilization Categories Utilization
categories for contactors according to IEC
60947-4-1
Current Type Duty Description
AC AC1 Non-inductive or slightly inductive loads, resistance furnaces. Power factor 0.7 0.8 (slightly inductive)
AC AC2 Slip ring motors starting, switching off
AC AC3 Squirrel cage motors starting, switching off motors during running. Power factor 0.4 0.5 (AC3).
AC AC4 Squirrel cage motors starting, plugging, inching.
AC AC5a Switching of electric discharge lamp controls.
AC AC5b Switching of incandescent lamps
AC AC6c Switching of transformers.
AC AC6b Switching of capacitor banks
AC AC8a Hermetic refrigerant compressor motor control with manual resetting of overload releases
AC AC8b Hermetic refrigerant compressor motor control with automatic resetting of overload releases
DC DC1 Non-inductive or slightly inductive loads, resistance furnaces
DC DC3 Shunt motors starting, plugging, inching. Dynamic breaking of d.c. motors
DC DC5 Series motors starting, plugging, inching. Dynamic breaking of d.c. motors
DC DC6 Switching of incandescent lamps
max
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DUROS contactors
Selection Applications

• Selection of a Contactor
• Proper selection of a contactor avoids many
  problems and maximize efficiency. The major
  factors to be considered while selecting a
  contactor are
• Type of voltage (AC/DC) and mains supply
  (Single/Three phase)
• Installed capacity
• Load characteristics
• Duty requirements (AC3 or else)
• Environmental conditions
• Standards required by certain organizations
• Areas of application
• Electric Motors
• Lighting
• Heaters
• Capacitor banks

• Furnaces
• Stabilizers
• Thermal evaporators
• Other electrical loads in Industrial Environment

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Contactors
Range Specification
BCH Range of contactors
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DUROS contactors
Range Specification
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