Which coil in a DC contactor is specifically responsible for the arc blowout effect?

• A. Hold-in coil
• B. Blowout coil
• C. Shunt coil
• D. Booster coil

Answer: (B)

Arc blowout is all about directing the arc away from the contacts so it can be safely extinguished. In DC circuits, the current doesn’t cross zero, so the arc tends to persist unless something actively drives it off the contact surfaces. The coil designed for this purpose creates a magnetic field that pushes the arc into the arc chute as the contacts separate. That controlled deflection speeds de-energization and reduces wear on the contacts.

Other coils perform different roles: a hold-in coil helps keep the contactor energized after pull-in, a booster (or booster) coil adds extra pull during energization to overcome friction or load, and a shunt coil handles other timing or control tasks. But none of those are specifically built to generate the arc-blowout effect like the arc-blowout coil.