Can I use AC contactor for DC?
Yes – as long as the rating of the A C contactor is a minimum of 5 x (preferably 6 x) of the D C contactor rating. This is mainly because of the steady state nature of the D C voltage and therefore its current. D C is generally used at lower voltage levels, common use and at very high levels for transmission purposes.
What is a DC contactor?
A DC contactor is an electrically controlled device designed to switch current on and off. DC contactors control current in DC circuits by closing and opening internal contacts. DC contactors control much lower voltages than AC circuits and offer the benefit of minimal arcing as the circuit opens and closes.
What is the difference between AC contactor and DC contactor?
An AC contactor has a high starting current with a maximum operating frequency of 600 times/hour. That of a DC contactor is about 1200 times/hour. A DC contactor uses a magnetic quenching arc, while an AC contactor uses a grid arc as an extinguishing device.
What is the difference between AC and DC coil?
A Dc relay coil has resistance that limits the dc current. An AC coil relies on its impedance for governing the current. An AC relay will remain contact closed due to mechanical inertia and a little mechanical hysteresis and, the fact that an alternating north and south pole both attract the relay armature.
Will a DC coil work on AC?
You can use AC coils on DC circuits providing you apply enough DC voltage to draw the same amount of current as when operating on AC. Basically, you apply a DC test voltage to the coil until you draw the same magnitude of operating (holding) current as when the coil operates on AC.
What would happen if both contactors were energized at the same time?
What can happen if both coils are energized at the same time? The mechanical interlock only allows one armature to pull in which causes the other coil to draw a current of 4 to 10 times higher than it’s pulled-in value. This causes the coil to burn out. Between the operating coils of the contactors and L2.
Why interlocking is used for the contactors?
What is Contactor Interlocking? When an electrical circuit has two contactors and only one of them needs to be turned on at a time then the interlocking system is used. The interlocking system ensures that only one contactor can be on while another one will be in off condition even if we try to manually on.
How does a DC coil in a contactor work?
DC contactors are electrical switching devices, similar to a relay. The contactor functions by applying a voltage to the coil, this creates a magnetic field which moves the contacts to the closed position and completes the circuit.
What kind of DC reversing contactor is 2 pole?
2 pole reversing contactor has been designed for direct current load, 2NO and 2NC ( DPST-NO, DPST-NC) contact form, rated load current is 400A. IP 50 protection, easy and quick installation, manufacturer direct sale.
How often does a 100A DC reversing contactor drop?
12V, 24V, 48V DC coil rated voltage for selection. Main contact voltage drop at 100A, not above 80mV. Mechanical life up to 300 thousand times.
What’s the mechanical life of a 12V 24V contactor?
12V, 24V, 48V DC coil rated voltage for selection. Main contact voltage drop at 100A, not above 100mV. Mechanical life up to 300 thousand times. Control line of the coil is too long, the residual voltage is too large due to the influence of lead capacitance, which is enough to maintain a close situation for the iron core.
When to use DC reversing contactor in oil pump?
When the coil powers on, magnetic adhesion disappears, the armature releases under the effect of retracting spring, thus restoring the contact: Normally open contact disconnects while the normally closed contact closes. DC contactor should be used in the DC power loop, such as the DC oil pump.