# Difference between ACB and VCB

**URL:** <https://forumautomation.com/t/difference-between-acb-and-vcb/13857>\
**Category:** Electrical\
**Tags:** circuitbreaker\
**Created:** [January 29, 2026, 2:32pm UTC](https://forumautomation.com/t/difference-between-acb-and-vcb/13857 "2026-01-29T14:32:43Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Rabert](https://forumautomation.com/user_avatar/forumautomation.com/rabert/32/6784_2.png) [@Rabert](https://forumautomation.com/u/Rabert)\
**Post date:** [January 29, 2026, 2:32pm UTC](https://forumautomation.com/t/difference-between-acb-and-vcb/13857/1 "2026-01-29T14:32:44Z")

</div>

## Difference between ACB and VCB

The difference between ACB and VCB are:

 ![3](https://cdn.forumautomation.com/original/2X/4/4104e44514e142ccc05ccbf0f6a90b674bea5439.jpeg)

| **Feature** | **ACB (Air Circuit Breaker)** | **VCB (Vacuum Circuit Breaker)** |
| --- | --- | --- |
| Full form | Air Circuit Breaker | Vacuum Circuit Breaker |
| Arc quenching medium | Air (at atmospheric pressure) | Vacuum (inside sealed interrupter bottle) |
| Voltage level | Used mainly in Low Voltage (LV) systems (up to 690 V) | Used in Medium Voltage (MV) systems (3.3 kV to 33 kV) |
| Typical current rating | 400 A to 6300 A | 630 A to 4000 A |
| Breaking capacity | Moderate (50–100 kA typical) | Very high interrupting capacity |
| Size | Large and bulky | Compact and smaller |
| Maintenance | High (contacts exposed to air, more wear) | Very low (sealed vacuum interrupter) |
| Contact erosion | Higher due to arc in air | Very minimal due to arc extinction in vacuum |
| Operating mechanism | Spring / motorized / manual | Spring / magnetic / motorized |
| Electrical life | Lower | Higher |
| Mechanical life | Moderate | Very high |
| Safety | Lower compared to VCB (arc exposure risk) | Higher (arc contained inside vacuum bottle) |
| Cost | Lower initial cost | Higher initial cost but economical long-term |
| Typical applications | LT panels, PCC, MCC, DG panels | HT panels, substations, transformers, motors |
| Insulation medium | Air | Vacuum bottle + air/epoxy insulation |
| Switching frequency | Moderate | Suitable for frequent switching |

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