Typical relay specifications break down maximum current into maximum carry current and maximum-switched current.
Carry current is defined as the current that can be passed by previously closed contacts. The cross-sectional area of the path from pin to pin through the switch limits carry current.
Switched current is the maximum current that can be interrupted by the relay. Contact plating and material are the primary factors in the switched current specification. If a high current is switched constantly across the contacts, the heat rises and arcing at the contacts degrades them at a rapid rate. In extreme cases, the contacts may weld together.
If the specified life of the relay is to be attained, power rating of the relay must also be complied with the current and voltage values.