LCP
RG66006889-Rev.01
18
6 ELECTRICAL
CONNECTIONS
6.1 GENERALITIES
Before carrying out any job on electrical parts, make sure the power supply is
disconnected.
Check that the mains electricity supply is compatible with the specifications (voltage, number of phases,
frequency) shown on the unit rating plate.
The power connection is made by means of a three-core cable plus neutral and earth cable or single-
core cables (one per phase) + earth according to the minimum cross section sizes specified in the wiring
diagram, which is an integral part of the documentation accompanying the chiller; the diagram code also
appears on the rating plate inside the compressor compartment.
The size of the cable and line protections must conform to the specifications provided in
the wiring diagram.
The supply voltage may not undergo fluctuations exceeding ±5% and the unbalance between phases
must always be below 2%.
The above operating conditions must always be complied with: failure to ensure said
conditions will result in the immediate invalidation of the warranty.
The electrical connections must be made in accordance with the information shown in the wiring diagram
provided with the unit and current regulations.
Electrical connections and preliminary checks:
Put on the main switch, turn the ½-turn locking screws of the electric enclosure and open it.
Introduce the power cable 400/3/50+N through the hole provided on the left side of the unit (after first
removing and making a hole in the aluminium square based on the diameter of the electric cable) and
secure it with a cable gland.
Connect the power supply and earthing wire to the terminals of the main switch.
Open the fuse carriers F1 and F2 (or Q1 and Q2 for the motor overload cutouts) of the compressors (F1-
F2-F3-F4 for the fuses or Q1-Q2-Q3-Q4 for the overload cutouts in the case of LCP 4 compressor models)
to prevent them from starting up in the wrong direction in the event of an incorrect phase sequence.
Switch on the power supply by turning the main switch (QS) to ON.
Verify whether the phase sequence R-S-T is correct by checking, on the phase sequence relay situated in
the middle of the electric control board, that the green power on LED and yellow LED indicating the correct
sequence both light up; if this does not occur, disconnect the chiller power supply from the external
distribution panel and swap over two phases; then repeat the operation. IN NO CASE SHOULD YOU
TAMPER WITH THE WIRING DOWNSTREAM FROM THE MAIN SWITCH since this may alter the correct
sequence of other devices, e.g. pump(s).
Close the fuse carriers F1 and F2 of the compressors (F1-F2-F3-F4 in the case of LCP 4 compressor
models).
Close the electric enclosure and lock it by means of the ½- turn locks.
An earth connection is required by law. The installer must connect the earthing wire using the earthing
terminal situated on the electric control board (yellow and green wire).
The power supply to the control circuit is shunted from the power line through an insulating transformer
situated on the electric control board.
The control circuit is protected by suitable fuses.
A
standard
feature of all units is a phase sequence relay that verifies the correct phase sequence; this is
necessary to assure that the chiller is completely functional before enabling a compressor start-up.
