14
Recommended Wiring Scheme
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4.5
Wiring Notes
WARNINGS!
When mains voltage is connected to the RVS-DXM, even if control voltage is
disconnected, full voltage may appear on the starter load terminals.
Therefore, for isolation purposes, it is necessary to connect an isolating device
before the starter.
Power factor correction capacitors and overvoltage devices must not be
installed on starters load side. When required, install capacitors or overvoltage
devices
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4.5.1
Short Circuit Protection
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for semiconductor protection to protect the RVS-DXM from a
short circuit.
Fuses for semiconductor protection give excellent results because they have low I²t values and high
interruption ratings.
Recommended fuse selection procedure:
(1)
Fuse rated voltage
: Choose minimum fuse rated voltage which is above the rated voltage of
the mains.
(2)
Fuse rated current:
Select a fuse which is able to carry 7 times the rated RVS-DXM current
for 30 seconds (this is double the maximum RVS-DXM current for the maximum acceleration
time).
(3)
Fuse I²t:
Verify that the I²t value of the fuse is less than or equal to the I²t value of the
thyristor in the RVS-DXM as shown in the table below.
RVS-DXM
Model
Max. Thyristor I
2
t
[A2Sec]
RVS-DXM
Model
Max. Thyristor I
2
t
[A2Sec]
210 135,500
515 1,820,000
240 135,500
590 1,820,000
310 845,000
720 1,820,000
360 845,000
840 1,820,000
414 1,130,000
960 4,260,000
477 1,130,000
1100 4,260,000
4.5.2
Transient Protection
Line transient voltages can cause a malfunction of the starter and damage to the thyristors. All RVS-
DXM starters incorporate Metal Oxide Varistors (MOV) to protect from normal line voltage spikes.
When higher transients are expected, additional external protection should be used (consult factory).
4.5.3
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4.5.3.1
General
information
When the RVS-DXM
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series with the individual motor windings (6 conductor connections as with the star-delta starter). The
soft starter must only conduct about 67 % (=1\1.5) of the rated motor current. This ensures the use of
a significantly smaller device.
For example:
For a motor with a rated current of 1050A motor, a 110
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1050 x 67% = 703A) and select a 720A starter.
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4.5.3.2
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-wire to the motor.
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Wrong motor connection will cause serious damage to the motor windings.
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When installing the RVS-DXM
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contactor in series to the RVS-DXM or upstream (after motor protection) in order to
avoid a destruction of the motor in case of a shorted SCR in the RVS-DXM.
