A hybrid air-gap / solid-state circuit breaker, comprising: a solid-state device; an air-gap disconnect unit connected in series with the solid-state device, the air-gap disconnect unit including: a holster having a first electrical contact; a holster retraction spring connected to the holster; a solenoid including a plunger; a holding member attached to the plunger; and a second electrical contact; and a control circuit configured to control whether the solid-state device is switched ON or is switched OFF, wherein: during normal operating conditions, the holding member is configured to hold the first electrical contact in contact with the second electrical contact, and to prevent the holster retraction springs from pulling the first electrical contact and the second electrical contact out of contact, and upon sensing that a fault or overload condition is present or developing in a load circuit, a control circuit is configured to transmit an electrical pulse to the solenoid, to cause it to reposition the plunger, causing the holding member to disengage from the holster thereby allowing the holster retraction springs to retract the holster so that the first electrical contact is separated from the second electrical contact, forming an air-gap therebetween. a solid-state device; an air-gap disconnect unit connected in series with the solid-state device, the air-gap disconnect unit including: a holster having a first electrical contact; a holster retraction spring connected to the holster; a solenoid including a plunger; a holding member attached to the plunger; and a second electrical contact; and a holster having a first electrical contact; a holster retraction spring connected to the holster; a solenoid including a plunger; a holding member attached to the plunger; and a second electrical contact; and a control circuit configured to control whether the solid-state device is switched ON or is switched OFF, wherein: during normal operating conditions, the holding member is configured to hold the first electrical contact in contact with the second electrical contact, and to prevent the holster retraction springs from pulling the first electrical contact and the second electrical contact out of contact, and upon sensing that a fault or overload condition is present or developing in a load circuit, a control circuit is configured to transmit an electrical pulse to the solenoid, to cause it to reposition the plunger, causing the holding member to disengage from the holster thereby allowing the holster retraction springs to retract the holster so that the first electrical contact is separated from the second electrical contact, forming an air-gap therebetween. during normal operating conditions, the holding member is configured to hold the first electrical contact in contact with the second electrical contact, and to prevent the holster retraction springs from pulling the first electrical contact and the second electrical contact out of contact, and upon sensing that a fault or overload condition is present or developing in a load circuit, a control circuit is configured to transmit an electrical pulse to the solenoid, to cause it to reposition the plunger, causing the holding member to disengage from the holster thereby allowing the holster retraction springs to retract the holster so that the first electrical contact is separated from the second electrical contact, forming an air-gap therebetween.