6. EASY ENGINEERING
• Made of metal sheet
• Painted so as to make rust
proof
• Weather Proof
• Indicators on it
Enclosure
7. EASY ENGINEERING
• On push button
– Used to Turn on the load
– Its Normally Open type (NO)
8. EASY ENGINEERING
• Off push button
– Used to Turn OFF the load
– Its Normally Close type (NC)
9. EASY ENGINEERING
Thermal Overload Relay
• It works on the principle of uneven expansion
of two different metals tied together
• On passing heavy currents, this bimetallic strip
will bend
• Leading to operation of relay
• Leading to opening of a coil circuit
• Leading to contactor opening
10. EASY ENGINEERING
Thermal Overload Relay
• It works on the principle of uneven expansion
of two different metals tied together
• On passing heavy currents, this bimetallic strip
will bend
• Leading to operation of relay
• Leading to opening of a coil circuit
• Leading to contactor opening
12. EASY ENGINEERING
CONTACTOR
• It do have a coil to attract the base of
terminals
• When current in coil starts it magnetizes and
latches up to ON main contacts
• Makes OFF when coil currents stops
• This coil is in series to relay
16. EASY ENGINEERING
NO Volt coil
• This coil actually turn off the contactor by
demagnetization
• Or turns ON by magnetization
• Also known as HOLD coil
