Airwell K CassetteSeries, Service & Installation Manual

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INSTALLATION – cont.
SUPPLY CABLE SIZING – AIR CONDITIONING UNITS
The manual provides a method of selecting cable sizes
which are large enough to ensure adequate voltage at
the unit terminals when starting and during normal full
load operation. The sizes determined are the minimum
acceptable to ECP (Australia) to ensure satisfactory
operation of the equipment.
Local wiring rules may appear to allow smaller wire sizes
to be used; however use of smaller sizes may lead to
operational problems and will void your warranty.
Selection of supply cables must be determined by
the following criteria:
1. Length of run of supply cables.
2. Maximum starting current of unit – cables must
supply adequate voltage at unit terminals for
starting.
3. Method of installation of supply cables.
4. Capability of cables to carry unit full load
current. (Starting and full load currents are
provided on the unit’s circuit diagram.)
Procedure
1. Select minimum acceptable wire size to handle
starting current – graph. 1.
2. Check that wire size from step 1 is adequate
for full load current – increase size as
necessary – graph. 2.
3. Check that larger wire size determined from 1
to 2 is acceptable under local wiring rules.
Graph 1 Graph 2
CURRENT CARRYING CAPACITY – AMPS. (Normal Full Load Current)
Single Phase Three Phase
1.5 2.5 4.0 6.0 Cable Size 2.5 4.0 6.0 10
.0
16 25 35
10 12 16 20 Completely Surrounded By thermal nsulation 12 16 20 25 32 40 50
16 20 25 32 Partially surrounded by thermal insulation 16 20 25 32 50 63 84
16 20 25 32 Enclosed in air (In Conduit) 20 25 32 40 50 80 92
20 25 32 40 Unenclosed in air (Not in Conduit) 20 25 40 50 63 80 100
25 32 40 50 Buried in ground or underground enclosure 25 32 40 63 80 100 120
15
20
25
30
35
40
45
50
55
60
35 40 45 50 55 60
STARTING CURRENT SINGLE PHASE UNITS
CABL
E
RUN (
m
)
WIRE SIZE
6.0 mm²
4.0 mm²
2.5 mm²
1.5 mm²
10
20
30
40
50
60
70
80
90
100
50 75 100 125 150 175 200
STARTING CURRENT THREE PHASE UNITS
CABL
E RUN (m)
WIRE SIZE
6.0 mm²
4.0 mm²
2.5 mm²
10.0 mm²
16.0 mm²
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