Undervoltage & Overload Standard

British Standard 7697.

The one you obviously don't have, but should.

Get a copy of the standards and read them.

And why do you hide behind a mask of an anonymous poster. What are you afraid of????

I think the permissible under and over voltage it is referred to the supplied equipment.

For instance, Rotating Equipment Standard IEC 60034-1 Fig.12 states -for frequency from 100 to 102% of rated-1.05 maximum overvoltage 0.95 of rated under-voltage. However, for a limited duration 110% over-voltage and up to 90% [under voltage] it is still permitted.

The overload depends on permissible insulation temperature limits and in turn on ambient temperature.

For cable the permissible maximum load [ampacity] depends on many factors but the limit is the maximum insulation permissible temperature for steady state, emergency or short time.

NEC ARTICLE 100-DEFINITIONS states: "The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment."

Try this.

It depends on what part of the world you are referring to as the standards vary. From memory, for Australasia it's AS/NZS 3000.

I meant ANSI/IEEE std

And the reason a search using keywords can not be carried out at that end in order to find it is what, please?

Oh, then I'm not sure as I don't normally have to refer to these series of standards.

Have you tried a quick internet search or a look online at one of the standards store?

Undervoltage and overvoltage would be naturally related. Undervoltage and overload are separate categories.

For Voltage Levels see:

ANSI C84.1, Voltage Ratings for Electric Power Systems and Equipment (60Hz).

For overload see NEC [Art.430 for motors or 310 for cables or other articles for specific equipment-lighting and so on]