Freuently Asked Questions (FAQ’s) about DC Contactors
Q: What is DC Contactor?
A: DC Contactors are used to switch the DC load devices connected with the sources, they are basically electronic operated switches which are operated by coil, hence, performs the switching tasks. Basically, they are used in replacement of Relays because they have high power carrying capacity than the relays.
Q: How DC Contactor works?
A: Contactor normally is placed Between the load and source, to switch load using contactor, the coil of the contactor can be energized to make it work. The coil closes the open contacts or open the closed contacts, it depend upon the design if its Normally Close or Normally Open.
Q: Types of Contactor?
A: There are two types of Contactors.
1): AC Contactors: To handle AC loads, their current carrying capacity varies according to the Voltage and frequency applied from the source.(skin effect)
2): DC Contactors: To handle DC load, frequency independent because there is no frequency in DC. Their Current carrying capacity changed according to the applied voltage.
Q: What is the difference between Contactors and Relays?
A: There is no specific difference between both, both works on the same working principal, which is electromagnetic switching. But the difference comes when it come to load power (current or voltage) handling, for high power applications the contactors are preferred over relays but mean time they are expensive than the Relays, and the Relays are comparatively used where low power application is required, so the Relays becomes the cheaper option for low load applications.
Q: Is there any effect on the capacity of Contactor because of type of the load?
A: Yes, there is effect on the capacity of Contactor because of the type of the load. If the load is pure resistive, then there is no effect on the capacity of the contactor, but if there is high inductive or high capacitive load then there is directly effect on the current handling capacity of the Contactor because the power stored in inductive and capacitive load float as extra power (reactive power) in system which degrades the current handling capacity of the Contactor.
Q: What is mechanical life of Contactor?
A: The mechanical life of the contactor gives the information about its switching cycles through its whole life span in normal usage condition.