Standalone Mutual Drainage Reactor

The Standalone Mutual Drainage Reactor is designed to protect communications equipment against the high voltages which may be induced onto telephone pairs, within a telecommunication cable during power fault conditions.

The Mutual Drainage Reactor provides a direct drainage path to ground for common mode induced voltages while maintaining a high impedance to AC differential telephone signals (typically 60 to 4000 Hz). The result is safe, uninterruptible communication before, during, and after fault conditions (ideally used on class “A” circuits).

Product Number CLEI Code Description
751200 PWUYACBMAA Standalone Mutual Drainage Reactor

The Mutual Drainage Reactor

The Mutual Drainage Reactor is generally intended to be installed outside the zone of influence of high voltage environments, in Central Offices (COs), and field cabinets.

NOTE: Please note that the installation procedure from the installation guide has been updated.


  • When the Mutual Drainage Reactor is connected across a telephone pair with its center tap grounded, the Mutual Drainage Reactor presents a high impedance to differential (metallic) AC signals on the line, while presenting a low impedance to ground for common mode (longitudinal) noise
  • The center tap may be grounded either directly or through a three element gas tube, depending on the application
  • The Mutual Drainage Reactor’s two coils are wound on a single core, and are fully interleaved. Each coil consists of two windings, with the inner winding of one connected to the outer winding of the other, to form one half of the Mutual Drainage Reactor. This form of coil construction ensures good transient response, even to lightning induced surges on the line
  • High drainage capability without signal distortion is achieved by ensuring that the separate coils are perfectly balanced and tightly coupled, and are of sufficient impedance to give satisfactory longitudinal balance and insertion loss figures at audio frequencies
  • The Mutual Drainage Reactor is encased in a plastic mold with attached metal flanges


Keyword Internal Search

Type the name or product number