www.morssmitt.com/rms for the latest product information. Page 5
Due to RMS continuous product improvement policy this information is subject to change without notice. 2V75_User_Guide/Iss C/08/05/23
Introduction
The 2V75 Metrosil module is designed for application with high impedance differential protection
schemes.
An external Metrosil module having a nonlinear resistance characteristic is required for each phase
element to limit the peak voltage appearingacross the secondary differential circuits under internal fault
conditions.
The Metrosil module may also be fitted with resistors either for series connection to establish the
stabilisation voltage of the high impedance scheme or shunt connection to alter the high impedance
scheme sensitivity.
The 2V75 Module provides a compact, simple & cost effective means of fitting a pre-wired Metrosil &
resistor combination into protection panels employing high impedance differential schemes.
Mounting is achieved by first fitting a special panel to the front of the cubicle. This panel is suitable for
19 inch rack or flush mounting.
TheseparateMetrosilmoduleistheninstalledfromtherearofthecubicle&latchedontotheself-aligning
rails on the front rack mounting panel. Retention screws are provided to lock the Metrosil module in
place.
The Metrosil module may, alternatively, be surfacemounted in the rear of the cubicle using the surface
mount bracket.
Heavy duty screw terminals are provided on the rear of the Metrosil module to suit ring or crimp lug
terminals. Internal wiring utilizes 2.5mm2cable.
The rear terminal door may be swung open to access the stabilizing resistors (where fitted) to allow
adjustment.
The completed installation is compact while providing safety isolation, the desired level of ventilationfor
the stabilizing resistors & a means of simple adjustment.
