Siemens Reyrolle 7PG23 High Impedance Protection Relay

The 7PG23 High Impedance Protection unit protection principle ensures sensitive, high speed operation for internal faults and guaranteed stability during external faults. The stability of the scheme depends upon the operate voltage setting being greater than the maximum voltage that can appear across the relay under a through fault condition. To ensure stability a setting calculation is required for every application to select the protection operate voltage and current settings.

A combination of stabilizing resistors, setting resistors and nonlinear voltage limiting resistors may be required to be connected into the high impedance circuit. The software tool simplifies the calculation and specification process and provides a method for recording the data, saving the engineer time. The High Impedance Software tool has been developed as part of the Reyrolle software suite and is free to download from the website.

The 7PG23 electro-mechanical single phase circulating current protection is used to detect earth faults in high impedance protection schemes. The relay is typically applied used in transformer protection schemes.One relay per phase can be applied to detect both phase and earth faults e.g. on reactors and stator windings of large machines.

The relay is a voltage operating device and has a user selectable operate voltage setting. The relay can be used in conjunction with an external shunt setting resistor where a higher operate current is required. An integral non-linear resistor limits over-voltages occurring during system faults. Operation flag indicator. Relays are housed in size E3 cases.

Protection Functions

• High impedance restricted earth fault

FEATURES

• One relay per phase can be applied to detect both phase and earth faults e.g. on reactors and stator windings of large machines.
• The relay is a voltage operating device and has a user selectable operate voltage setting. The relay can be used in conjunction with an external shunt setting resistor where a higher operating current is required. An integral non-linear resistor limits over-voltages occurring during system faults. Operation flag indicator. Relays are housed in size E3 cases.
• User selectable voltage setting
• Integral voltage limiting device
• Operation flag indicator

The comprehensive range of Reyrolle products provides the total protection requirements of distribution markets and industrial applications – ranging from overcurrent protection via transformer protection and voltage control to a full spectrum of auxiliary and trip relays. The portfolio includes many famous products such as “Argus, “Duobias”, “Solkor”, “Rho, etc. Through successive generations, Reyrolle numerical products have been developed to increase value to system operators. Discover the portfolio!