1.3 Wiring (for looms other than towel weaving machine)
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1.3
Wiring (for looms other than towel weaving machine)
1.3.1
In-plant Electric Facilities
The in-plant electric facilities shall be set up as specified below to make the most of the loom perfor-
mances while maintaining safety.
For details, consult with electric specialists or electric companies.
[ 1 ] Power Requirements
The power supply voltage fluctuation shall be the contracted voltage
±
5%, the frequency fluctuation
shall be 50/60 Hz
±
2.5% and the voltage unbalance between phases shall be within 3% continu-
ously. Be especially careful in the electric set-up work so that the supply voltage and frequency do
not go out of the specified ranges above even instantaneously.
[ 2 ] Earth leakage breaker
Install an earth leakage breaker in the power supply circuit to prevent hazards which may be caused
by leakage current.
Select the earth leakage breaker in consideration of the high frequency component generated by
the inverter. Please consult with a specialized company.
The loom with an electronic shedding motion leaks larger current than the conventional looms.
Leakage current measured at our laboratory (reference):
The electronic shedding loom leaks current of about 40 to 80 mA, and the cable between the earth
leakage breaker and the loom control box leaks about 10 mA. The leakage current, therefore, totals
to 50 to 90 mA.
Since the leakage current varies with the cable connection method and the cable length, use the
earth leakage breaker with a rated capacity of 200 mA or over (only for the electronic shedding
loom).
[ 3 ] Class D grounding
Connect the grounding wires to the grounding terminal (marked PE) in the control box.
[ 4 ] Capacities of non-fuse circuit breakers on switch board
When starting the loom in the delta mode, a rush current at approx. 20 times the motor rated current
flows instantaneously.
Select a circuit breaker whose rating is at least four times the nominal rated current of the motor for
installation on the switchboard.
If the capacity is insufficient, frequent tripping will occur.
[ 5 ] Cable capacity selection
Frequent warp miss or loom malfuction may occur upon starting of the loom in the delta mode
because of instantaneous voltage drop.
Select a cable capacity so that the total of supply voltage fluctuation and the voltage drop by the
cable is within 10% of the contracted voltage.
