ADR241S – Self Powered Relay For RMU

  • numerical self powered protection relay
  • ADR241S-Vertical cabinet
  • Self Powered relay Draw Out Cabinet

General Description

ASHIDA is a leading Indian manufacturer & supplier of complete range of Numerical, Static & Auxiliary Protection Relays. ADR241S is second generation of Numerical Self Powered OC / EF IDMT/DT Relay. The ADR241S gives maximum benefit/cost ratio. This self-powered relay gives all the advantages of numerical relay at affordable cost.

The ADR241S is self powered relay, communicable 3 OC and 1 EF with Instantaneous high set specially designed for Protection of Ring Main Unit or compact sub-station where no any external power supply is not available.

The self-powered relay (ADR241S) is designed for Over Current Protection Function with three independent states (I>1, I>2 & I>3). Each stage can be programmed as IDMT or Definite Time (DT). All major international IDMT curves are available.

The self-powered relay includes undercurrent elements that can be used to provide additional functions to prevent damage to the power system. This function allows typical applications such as loss of load.During switching of load, there is sudden surge of magnetizing inrush current. The self-powered relay is designed to block this inrush current to avoid the false tripping.

In self-powered relay, thermal overload protection is designed to prevent the electrical equipment when operating temperature is exceeded the maximum designed temperature. The fundamental currents are measured and analyzed to monitor the thermal state.

In normal condition the relay displays actual current flowing through the relay. If current is in fault range the self-powered relay gives trip command. The type of the fault is displayed on LCD display. All settings can be done locally as well as remotely via communication port and saved in non-volatile memory.

The self-powered relay continuously keeps track on its internal hardware and at the movement it detects any failure of any component, it gives message on LCD display. This feature is very useful to give pre information to avoid any mal-operation.

ANSI Protection Functions
50 Instantaneous Over current Protection (OC-Inst.)
50N Instantaneous Earth Fault Protection (EF-Inst.)
51 Time Over current Protection (Phase) (OC-IDMT.)
51N Time Over current Protection (Earth) (EF-IDMT.)

Model Functional Details Cabinet Style
ADR241S Communicable self powered Numerical Over current / Earth fault Relay. Horizontal – 260mm x 140mm x 182mm (With Clamps)

ADR241S Communicable self powered Numerical Over current / Earth fault Relay. Vertical – 161mm x 182mm x 145mm (With Clamps)

ADR241S Communicable self powered Numerical Over current / Earth fault Relay. Draw Out – 174mm x 160mm x 196mm (With Mounting)

Numerical Self Powered Protection Relay For RMU : ADR241S


  • 4 Element (3 Phase + EF) over current IDMT with instant trip.
  • Display of fault current. / Load current.
  • Selection of Curve: Six selectable curves (Normal Inverse1 (C1), Normal Inverse2 (C2), Very Inverse (C3), Extremely Inverse (C4), Long Time Inverse (C5) & Definite Time (C6).
  • Separate curve selection for phase and EF.
  • Latching of fault current up-to last 5 fault.
  • Programmable Annunciation Contact
  • SCADA compatibility. IEC60870-5-103 protocol.