Type A vs. Type B
Comparing 2 standards across 5 specifications. 3 key differences identified.
Type A is the ungrounded 2-flat-pin plug standard in North America, Central America, and Japan -- NEMA 1-15, rated 15A/125V. It's a physical subset of Type B: any Type A plug fits directly into a Type B socket, the ground pin recess simply unused.
Type B adds a round grounding pin to Type A's two flat blades -- NEMA 5-15, the most common outlet in North America. The ground pin is deliberately longer than the power blades, so it connects before and disconnects after them, a safety-sequencing feature shared with several other grounded plug types worldwide.
Specification Comparison Table
5 Parameters| Parameter / Spec | ||
|---|---|---|
|
Pin Count
|
2 flat parallel blades, non-coplanar, 12.7mm apart | 2 flat blades + 1 round ground pin (longer than the blades) |
|
Rated Current
|
15 A | 15 A |
|
Rated Voltage
|
125 V | 125 V |
|
Grounded
|
No | Yes |
|
Common Regions
|
USA, Canada, Mexico, Central America, Japan | USA, Canada, Mexico, Central America, Japan (grounded appliances) |