Zones of Protection device 
• An electric powered powered powered powered powered power device is break up into numerous zones of safety. Each region of safety, consists of one or more additives of a power device further to 2 circuit breakers. 

• When a fault takes location withinside the boundary of a particular region, then the safety device liable for the safety of the arena acts to isolate (through way of method of tripping the Circuit Breakers) each device internal that region from the relaxation of the device. 

• The circuit Breakers are inserted some of the trouble of the arena and the relaxation of the power device. Thus, the place of the circuit breaker permits to outline the limits of the zones of safety. 

· Different neighbouring zones of safety are made to overlap every other, which make certain that no a part of the power device stays with out safety. However, occurrence of the fault with withinside the overlapped area will provoke a tripping series of severa circuit breakers sincerely so the minimal vital to disconnect the defective element.

Types of Protection (Primary and Back-up Protection)

Primary Protection 
The primary protection scheme ensures rapid and selective clearing of any fault withinside the restrictions of the circuit element, that the location is wanted to protect. Primary Protection maximum likely is furnished for each phase of an electrical installation. 
However, the primary protection may additionally moreover moreover furthermore fail. The primary cause of failure of the Primary Protection device are enumerated below. 
1. Current or voltage supply to the relay. 
2. D.C. tripping voltage supply 
3. Protective relays 
4. Tripping circuit 
5. Circuit Breaker 
Back-up Protection 
Back-up protection is the choice given to a protection which backs the primary protection on every occasion the later fails in operation. The back-up protection with the beneficial useful beneficial aid of using definition is slower than the primary protection device. The format of the back-up protection desires to be coordinated with the format of the primary protection and essentially it`s miles the second line of defence after the primary protection device.

The over voltage stresses carried out upon the power tool, are normally quick in nature. Transient voltage or voltage surge is described as surprising sizing of voltage to a excessive top in very quick duration. The voltage surges are quick in nature, which means they exist for distinctly quick duration. The important purpose of those voltage surges in power tool are because of lightning impulses and switching impulses of the tool. But over voltage withinside the power tool can also be added approximately by, insulation failure, arcing floor and resonance etc. 
The voltage surges seem withinside the electric power tool because of switching surge, insulation failure, arcing floor and resonance aren`t very big in magnitude.