... , Ukraine, Poland, UK. Italy, etc. WTO6 series surge protective device (in short :SPD, alias : surge protector, surge arrester) is suitable for TN ... the module of surge protective device. When the SPD fails in breakdown for over-heat and over-current ,the failure release ... when has operating voltage. Shanghai CET Group have 7 branches in China to produce:Circuit breaker: mcb, rccb, mccb, rcbo.AC ...