1. Introduction
The reactive power electronic relay RC4 allows the delayed insertion of 4 capacitor
banks, automatically with the changing of power factor, measured on the supply line, or
manually by means of commutators set on the front of the board.
The presence of signal-leds allows a simple knowledge of the maneuvers and of the
measures carried out from the relay.
The insertion of the capacitor banks is made according to a logic that optimizes the
number of maneuvers and does not stress the operating organs of the p.f.c. plant.
2. Arrangements
For a correct operation of the regulator it is necessary to preset the following parameters:
- Target power factor
It represents the power factor value that you want to obtain in the plant: the regulator inserts
the capacitor banks till reaching the pre-set power factor value. The presetting is made by 2
micro switches on the front by choosing one of the three possible values: 0.92 - 0.96 – 1.00.
Attention: the 2 switches moved on the left do select the value 0.92. Do not set both
switches on positions on the right 0.96 - 1.00.
- C/K
It represents the relation between the capacitance of the first bank (kvar) and the ratio
(K) between the primary current and the secondary of the CT.
Example:
The RC4 allows the choice among the 7 possible values of C/K:
0.07 - 0.08 - 0.1 - 0.2 - 0.4 - 0.5 – 1
A good choice of the C/K value is essential for a correct operation of the regulator. It is
important to install a CT with a primary current value as close as possible to the nominal
current value of the plant, in order to permit a precise measurement of the power factor
value and of C/K coefficient of sensitiveness.
Attention: the 6 switches moved on the left select a C/K value = 1. Do not set more
than a switch on the right.
ITALFARAD S.p .A. via IV novembre n.1 Minerbio (BO) It aly
capacitance 1st bank = 20 kvar
K = 100/5 = 20
C/K = 1
12
GB