Electric meter ratings (amperage)

[nss70]

Curiosity question.( seen in DIY shop )

What do the markings mean on a standard single phase meter?

e.g. " 15 (45)A "

Is that a 15A or a 45A meter, and why the two different numbers?

 

 

[Crossy]

The first number is the calibration current (where it's most accurate), the second is the maximum current.

 

In reality meters are incredibly robust, a 100% overload won't cause issues other than a loss of accuracy (bet they don't read low).

 

Most 15/45 meters are on a 63A main breaker.

 

[lopburi3]

As above - the meter/service is called 15A

[nss70]

Thank you gents.