11
3. INSTRUCTION for the USE
3.1
ELECTRICAL CONNECTION
: by means of plug connector with terminal fixing screws for the cable
have to be of 2,5mm
2
section, mounted in the base of the regulator.
Number of
terminal
Label of
terminal
Description
1
P2
N.O. 5Amps - 250Vac clean contact (resistive load) to be used for control the panel ventilation
2
P1
fans.
3
X1
N.C. 5Amps - 250Vac clean contact (resistive load) to be used for remote alarm signalling.
4
X2
Separate supply required (see chapter 7. ALARMS).
5
C
Common terminal of relays. To be connected to 220Vac auxiliary transformer.
Note: Protect connection with external fuse max. 4Amps.
6
÷
13
8
÷
1
Connection to contactor coils (from 8
th
to 1
st
bank).
14
A
Connection to secondary of C.T.
15
A
C.T. = Current Transformer with 5Amps secondary (see chapter 3.)
16
V
Connection to 0Vac - Protect with external fuse.
17
N.C.
Not connected
18
V2
Connection to 380Vac - Protect with external fuse.
3.2
MECHANICAL FIXING: t
he regulator should be mounted in a cut-out (drilling template 138x138mm.)
using the special fixings supplied.
3.3
POWER of CONTROLLED BANKS:
the regulator works according to binary logic sequence; the
switching on and off of capacitors banks always start from the first bank. For correct operation of the
automatic bank, the power ratio per bank should be:
a. equal to each other
(1-1-1-1-1-1-1-1)
b. double of the previous bank
(1-2-4-8-16-32)
c. equal or double of the previous bank
(1-1-2-2-4-4)
3.4
NUMBER of STEPS:
is determined by the power combination which has been used on single capacitors bank:
Examples:
6 banks in the sequence 1-1-1-1-1-1
make 6 steps
6 banks in the sequence 1-1-2-4-4-4
make 16 steps
6 banks in the sequence 1-2-4-8-16-32 make 63 steps
Note. Where the step sequence is uneven too high a number of steps will result in a high number of switching
operations, which will considerably reduce the life of the equipment. With the first step too high hunting may
occur which again would produce excessive wear and reduced life of the components.
•
NORMALLY 8-16 REGULATIING STEPS IS THE BEST SOLUTION TO ADOPT
Fig. 1
The external connection
•
It is very important to
ensure correct
connection of the CT
(in L1 phase upstream
of the load and phase
shifting capacitors)
and the voltage
connection (on phases
L2 and L3), as shown
in the schematic
below, in order to
ensure a correct
measurement of the
unit.
MPR8
