Power Cables Connection; Apcl1 And Apcl2 Boxes; Figure 3.3. Connection Of Several Banks In Parallel - ABB APC Series Installation, Operation And Maintenance Instructions

CT1
TO FEEDER
The switching delay time of each master unit must slightly differ from the other ones.
If the controllers are set to normal mode, we recommend using a switching time delay difference of 1 sec.
(e.g. 40s, 41s, 42s, ...)
If the controllers are set to integral mode, we recommend using a switching time delay difference of at least
21 sec. (e.g. 120s, 141s, 162s, ...)
Note that each bank may include either a single master unit or a master unit plus a slave unit.
3.4.3.

Power cables connection

When selecting the appropriate cable size due consideration should be given to possible future extension of
the equipment. Cables and isolating switchgear should be rated at 1.5 times the nominal capacitor current of
the total capacitor bank and should always be coordinated with the current rating of the back up fuses.
Cross section of supply cables
The different parameters like localization, temperature, etc... and other factors which may exist, do not allow
to cover all the possible cases of installation and simple rules. The standards in force in the concerned
country have to be taken into consideration keeping in mind that the current must be considered as a
minimum 1.5 times the nominal current.
Master switch and fuses
At the location of the bank installation, the power of the network short-circuit must be taken into consideration
to define the main connection fuses, or rating of the circuit breaker.
To disconnect the unit from the network, we suggest preferably a circuit breaker. A 3-phase disconnecting
fuse or a 3-phase switch with fuses may nevertheless be used.
The apparatus should be chosen with a nominal current rating of minimum 1.5 times the rating of the
capacitor bank.
It is to be noted however that the fuses, if any, must be calibrated to protect the cables and at least at 1.6
times the rating current of the capacitor bank.
3.4.3.1.

APCL1 and APCL2 boxes

APCL1 and APCL2 are factory mounted with a bottom cable entry.
A knock out is provided for this purpose.
14
TO LOAD
BANK1 BANK2

Figure 3.3. Connection of several banks in parallel

CT1 CT2
TO FEEDER
BANK1
APC - Chapter 3. Installation
TO LOAD
BANK2