Relays and contactors carry the same function by switching a circuit. If you see from the application point of view, you see a magnetic contactors placed inside an electrical panel board use to control electric motors, heaters and other heavy loads. while, relays are used in low voltage applications such as alarms and pilot lights, etc.
Both shares the same function electromagnetic switching and operate under the same principles.

Relays
are typically used in circuits that have a maximum load current rating of 20 amps, but most of the time are not used in circuits that require more the 15 amps.
- Normally only used in single phase applications

Contactor
Can be used to switch loads with current anywhere from 20a – 12500A
Normally consist three separate contacts designed for used in three phase power applications.
A magnetic contactor have 3 main contacts L1,L2,L3 or 1,3,5 and T1, T2, T3 or 2,4 and 6 and have many auxiliary contacts like NO and NC for interlocking and making other circuit Power contactor is generally used in a large amount of current to make and break a large carrying load like 10 horsepower motor to 900 hp
High voltage AC contactors (greater than 1,000 volts) may use vacuum or an inert gas around the contacts. In EXTINGUISH ELECTRIC ARCS

свернуть