transformer protection

Applications l Protection and measurement of 10KV/400V Y/YO Transformers Configuration of Protecting Functions l Quick break protection l Over current protection l Zero sequence current protection (inverse time lag) l Load control l Low frequency load decreasing with low current and lockdown when frequency slipping l Fault recording Characteristics of Module l Providing double CPU structure with self-check and cross-check l Providing a large screen LCD in English l Providing RS-422(485) or RS-232 or CAN communication interface and remote operating function l All protection functions can be switched by software l Protection output can be switched by hard pressure board l Applicable in AC or DC power supply l Preset protection constant value can be modified remotely Main technical Parameters l Presetting range of quick-break: 4A-100A, with level difference of 0.1A Presetting range of quick-break time: 0-5s, with level difference of 0.01s l Presetting range of over-current: 1.0A-50A, with level difference of 0.1A Presetting range of over-current time: 0-10s, with level difference of 0.01s l Presetting range of overload range: 1A-10A, with level difference of 0.1A Presetting range of overload time: 2-60s, with level difference of 0.01s l Zero sequence current: setting 5 points at random with inverse time lag l Presetting range of low frequency: 45-49.9Hz, with level difference of 0.01Hz Presetting range of low frequency time: 1-60s, with level difference of 0.1s l Presetting range of low current closedown: 0.5A-10A, with level difference of 0.1A Presetting range of frequency changing rate closedown: 0-10Hz/s, with level difference of 0.1Hz/s l Contact capacity of output relay: DC220V, 5A l Environment temperature permitted Normal working temperature: 0°C +45°C Utmost working temperature: -10°C- +50°C l Anti-interference: Complying with the regulations of GB7261-87 and IEC255 l Insulation and voltage withstanding: fulfill the regulations of DL478-92 Measuring Functions Measuring current: ia, ic P, Q, COS¢, f, Uab, Ubc Protection electricity: Ia, Ib, Ic, i KWh, KVarh Clock Digital pulse count of electric energy 8-bit telesignalling amount