Ngwa JR28 usoro thermal overload relay dabara adaba maka oke ibu na nchekwa ọdịda nke AC Motors nwere ugboro 50/60Hz, voltaji ruo 690V, ugbu a ruo 0.1-630A n'okpuru ọrụ awa 8 ma ọ bụ ọrụ anaghị akwụsị akwụsị.Ọrụ nke relays ndị a na-enye, bụ nchebe ọdịda nke oge, ihe ngosi ON/ Gbanyụọ, nkwụghachi okpomọkụ, na akwụkwọ ntuziaka/akpaghị aka. Ọkọlọtọ mba ụwa: IEC 60947-4-1 Enwere ike itinye relays na kọntaktị ma ọ bụ tinye ya dị ka otu nkeji.