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Dinel, s.r.o. PDU–4xx–W
The unit is not equipped with an internal fuse or power supply circuit breaker. Because of this an exter-
nal time-delay cut-out fuse with a small nominal current value must be used (recommended bipolar,
max. 2A) and a power supply circuitbreaker located near the unit. In the case of using a monopolar
fuse it must be mounted on the phase cable (L).
The power supply network cable diameter must be selected in such a way that in the case of a short
circuit of the cable from the side of the unit the cable shall be protected against destruction with an
electrical installation fuse.
Wiring must meet appropriate standards and local regulations and laws.
In order to secure against accidental short circuit the connection cables must be terminated with ap-
propriate insulated cable tips.
Tighten the clamping screws. The recommended tightening torque is 0.5 Nm.
Loose screws can cause fire or defective operation. Over tightening can lead to damaging the connec-
tions inside the units and breaking the thread.
Due to possible significant interference in industrial installations appropriate measures as
-
suring correct operation of the unit must be applied. To avoid the unit of improper indications
keep recommendations listed below.
• Avoid running signal cables and transmission cables together with power supply cables and ca-
bles controlling inductive loads (e.g. contactors). Such cables should cross at a right angle.
• Contactor coils and inductive loads should be equipped with interference protection systems, e.g.
RC-type.
• Use of screened signal cables is recommended. Signal cable screens should be connected to the
earthing only at one of the ends of the screened cable.
• In the case of magnetically induced interference the use of twisted pair of signal cables is recom-
mended. Twisted pair (best if shielded) must be used with RS-485 serial transmission connec-
tions.
• In the case of measurement or control signals are longer than 30m or go outside of the building
then additional safety circuits are required.
• In the case of interference from the power supply side the use of appropriate interference filters
is recommended. Bear in mind that the connection between the filter and the unit should be as
short as possible and the metal housing of the filter must be connected to the earth with the larg-
est possible surface. The cables connected to the filter output must not be run with cables with
interference (e.g. circuits controlling relays or contactors).
