Baldwin B r i d g e r , J r . , P . E . and Seni o r Member IELX Powell E l e c t r i c a l Manufacturing C o . 8550 Mosley D r . Houston, TX 77075 U.S.A. Abstract-Electro--mechani c a l p r o t e c t 1 vc, rf,l ays ai-.. r e q u i r e t h e s e r e l a y s t o o p e r a t e normally w h i l e exposing them t o t i l t i n r : and o s c i l l a t o r y motion. A v a r i e t y o f e l e c t r o -m e c h a n i c a l and s o l i d --s t a t e p r o t e c t i v e r e l a y s were t e s t e d for-pickup and time d e l a y c h a r a c t e r i s t i c s w h i l e t i l t e d i n s e v e r a l d i r e c t i o n s from v e r t i c a l and whi IC undrrKoinr: o s c i ll a t o r y motion. These tests showed t h a t indui-tion d i s k arid i n d u c t i o n cup r e l a y s were s e r i o u s l y a f f r c t e d by t i l t i n g and motion, b u t t h a t hinged armature and s o l i ds t a t e r e l a y s were not a f f e c t e d .