Protection Of Transformers
The simplest diaph nozzle schema is a differentiational stack that is used when it meets the sensitivity requirements. If this condition is not met, the longitudinal defensorship uses a relay like a NT.
RNT relays have saturated transformers (NTs) that reduce the currents caused by the currents of moisture and the currents of the inequilibrium created during the transition process with external short circuits and compensate for the inequities of secondary current transformers.
Pressure regulators with load or multi-multiple transformers with multi-mouths where, due to large currents of non-balance in the relays in the exterior short circuits, protection with saturated transformers does not provide the required response, provision is made for dyphproof protection with braking and reset of the type of DDT.
Preliminary protection shall be calculated for the case of relay without braking.
If it is not sufficiently sensitive, the relays shall be applied with a minimum number of brakes providing the required response. The longitudinal defensive response point shall be detached from the currents of nebalance and the currents.
Protection of power transformers against internal damage
In order to protect against internal damage (vibrous circuits in gas-discharged boilers) and from lower oil levels on 6,300 kVA and above transformers, and 1,000 to 4,000 kVA transformers with no dysfunctional or cut-off, and if the maximum current protection has a delay of 1 s and more, the gas-tight warning shall be applied when the gas is actuated. The use of gas protection is mandatory on 630 kVA and above in-house transformers, regardless of other fast-track protections.
Gas protection shall be installed on transformers, transformers and oil refrigeration reactors with extensions, and shall be carried out by means of floating, blade and viscous gas relays. Gas protection is the only protection of transformers from steel fires, a magnetic wire that occurs when the isolation is broken between steel sheets.
Permissible gas protection a signal, both with weak and strong gas formation, on transformers with dysfunctional or non-concluding dysfunctions and 1,600 kVA intrace capacity and less with protection against short circuits by the power source.
