Distance Relays

Reactance relays cant be made directional. A directional element cant be added to them since these relays operate under normal load condition and U.PF.

Reactance relays are used for ground faults because a ground fault relay should be independent of ground fault resisntance. ( which is variable).

Used for < 10 miles ( Short T.L.).

Mho relay or admittance relays ( for 50 miles +) is used for phase fault condition.

Arc resistance affects an impedance relay more than a reactance relay but less than Mho relay.

Bundled conductors

Advantages:-

• Reduced reactance.( L is reduced)
• Reduced voltage gradient. 
• Reduced corona losses.
• Reduced Radio intrerference.
• Reduced surge impedance.
• Oncreased capacity of transission.