T-CU19-JAN24-1
Page 13
Electrical
Below table lists recommended wiring sizes for the
condensing unit power supply cables. These wiring sizes are
valid for cable lengths up to 30m.
Table 10: Recommended wiring sizes
Model
Cable size, mm
2
(from network
to unit main switch)
LRMIFS0300AXY1
4
LRMIFS0600AXY1
4
LRMIFS0900AXY1
6
•
Note: Above is just a guideline for wire size. Installer
might specify cable size different from this guideline,
depending on the wire material and length, system
design, ambient temperature, etc.
•
Cables to the condensing unit should wherever possible
be routed through the cable glands supplied on the
rear panel and routed through the wire bush/cable
gland designated for the incoming supply at the control
box casing.
Separate power cables as
much as possible from the
probe and digital input
cables to avoid possible
electromagnetic
disturbance. Never run
power cables and signal
cables in the same conduits.
•
Connect the mains supply to the units as per the wiring
diagrams shown in
Figure 23-25
.
•
Ensure that the power supply corresponds to the unit
and that the power supply is stable.
•
Connect power supply according to the present norm
and legal requirement. Ensure that the unit is properly
connected to the ground.
•
The unit is equipped with a motor circuit breaker with
overload protection for frequency drive. Overload
protection is preset from factory and value can be
found on the wiring diagram adhered on the control
box cover.
•
Unit equipped with manual reset high pressure switch
and auto reset low pressure switch.
•
If system pressure exceeds high pressure switch cut out
pressure, it will immediately break the circuit to digital
input
“Safe Torque Off (STO)” on the drive. When the
STO contact is open, the drive stops operating,
bypassing the software control.
Phase Sequence for Correct
Compression
BLDC scroll compressor requires proper
phase sequence to secure correct rotation
direction and therefore compression. The
phase sequence has to be secured between
the drive and compressor. Compressor rotation direction
is not influenced by the phase sequence between
network and unit drive.
Warning When Touching Unit
When OFF
Frequency converters contain DC-link
capacitors that can remain charged even
when the frequency converter is not
powered. To avoid electrical hazards,
disconnect AC mains and wait at least 5
minutes for the capacitors to fully discharge before
performing any service or repair work. Failure to obey
this instruction before conduct service or repair could
result in death or serious injury.
The digital inputs are not a safety switch. The frequency
converter is still powered even though it was cut off by
digital input via alarms activation. Thus, do not remove 3
phase connections to the frequency converter, compressor
connections or other power connections while the frequency
converter is connected to power.
Earth Leakage Current
This product integrates a frequency converter
which can cause ground leakage currents
exceeding 3.5mA.
According to IEC 61800-5-1 a reinforced
Protective Earth connection must be ensured
with a min. 10mm
2
or an additional PE wire which must
at least same cross section as the mains supply wires-
must be terminated separately.
This product can cause a DC current in the protective
conductor. If a residual current device (RCD) is used for
extra protection on the mains supply side, it must be a Type
B (time delayed). The use of RCD and protective earth for
the frequency converter must always follow national and
local regulations.
