User Guide

3RT1 contactors/3RH1 control relays
SIRIUS System Manual
GWA 4NEB 430 0999-02 DS 01
3-41
3.3.5 3RT16 capacitor contactors
Field of application 3RT16 capacitor-switching contactors are used to switch power capacitors
that are used in reactive-current compensation.
Frame sizes The capacitor-switching contactors are available in frame sizes S00, S0 and
S3 with the rating levels 12.5, 25 kvar, and 50 kvar at 400 V.
Fig. 3-18: Capacitor contactors (frame sizes S0 and S2)
Auxiliary contacts The auxiliary contact block attached onto the capacitor contactor contains
three leading NO contacts and a normal NO contact that can be assigned as
you wish. In Frame size S00, an additional 1 NC contact is available in the
base unit. A 2-pole auxiliary switch block can also be attached to the side of
the frame size S3 capacitor contactors (variants: 2 NO contacts, 2 NC con-
tacts, or 1 NO + 1 NC contact).
Switching capacitors/
banks of capacitors
A single capacitor can normally be switched on because the current is lim-
ited by the inductance of the upstream transformer and the cables. It is
more difficult to switch banks of capacitors (parallel connection of a capaci-
tor to capacitors already present) because the current is now only limited by
the low inductance of the connecting leads and the capacitors.
This problem is solved with capacitor-switching contactors using precharg-
ing resistors.
Precharging resistors The precharging resistors are an integral part of the contactor in 3RT16
capacitor-switching contactors. They are switched on via leading auxiliary
contacts before the main contacts close. This results in damping down to
approximately 10 % of the undamped peak currents. Damping of peaks in
the making current prevents disturbances to the network.
S00
S3
RT-01022
RT-01023