Common alarm system for a plurality of circuit interrupters

Apparatus comprising:

• a plurality of circuit interrupters each having an on condition, an off condition, and a tripped condition, and each having an associated means for providing an indication of said tripped condition comprising a handle having an on position when the associated interrupter is in said on condition, and off position when the associated interrupter is in said off condition, and a tripped position when the associated circuit interrupter is in the tripped condition, and wherein said circuit interrupters are arranged with said handles of said plurality of circuit interrupters aligned when in said tripped condition;
• common alarm means responsive to said means providing an indication of said tripped condition associated with each circuit interrupter for generating a common alarm indication when any of at least selected ones of said circuit interrupters is in said tripped condition, said common alarm means comprising beam generator means generating a beam of radiant energy, detector means responsive to said beam of radiant energy, said beam generator means and detector means being positioned such that said beam of radiant energy impinges on said detector means except when any of said handles is in the tripped position, whereupon said detector means generates a common trip signal, common alarm indication means activated by said common trip signal, and delay means preventing generation of said common trip signal in response to momentary blocking of said beam of radiant energy from impinging on said detector means when a handle is moved through, but does not remain in said tripped position for more than a predetermined time interval.