Installation 213
14.9 Wiring instructions
Note. The PL/X controller is an open chassis component for use in a suitable enclosure. Only qualified
personnel should install, commission and service this apparatus according to the safety codes in force.
1) All units must be protected by correctly rated semi-conductor fuses. (3 main fuses and 3 auxiliary fuses)
Failur e to do so will invalidate warra nty. See 14.3 Semiconductor fuse ratings. A D C armature fuse for
regenerative applications is highly recommended. See 14.3.3 D C semi-conductor fuses.
2) Po wer wiring should utilise cables with a minimum rating of 1.25 X full load current. Control wiring should
have a minimum cross-section of 0.75mm
2
. Copper conductors must be rated 60C, or 75C over 100 A mps.
3) A substantial ground or earth connection shoul d be made to the earth terminal on the drive i dentified by
the internati onal ground symbol. A control clean protective earth connection must be made to terminal 13.
4) A 3 phase contactor must be connected in the main A C supply with suitable voltage and current ratings.
(AC1). The contactor is not required to switch current and is employed in the sequencing and carrying of
po wer to the unit. The contactor coil must be provided with a suitable control supply which is applied by the
controller to the contactor coil using terminals 45 and 46. If for safety r easons it is mandated that the
contactor coil must be able to be de-energi sed externally to the drive, then it must be arranged that the
CSTOP terminal 35 is opened at least 100mS prior to the opening of the main contactor. Failure to achieve
this will prevent the armature current from being able to commutate to zero prior to supply removal and may
result in damage to the unit. Failur e to heed this warning will invalidate warranty. See 4.3 Main contactor
wiring options, for advice on using D C side contactors, or other po wer sequencing options.
5) For contactor coils with a V A rating that exceeds the ratings of terminals 45 and 46, it is necessary to
utilise a slave relay of suitable rating to drive the contactor coil.
Note. If the users main contactor has a final closing time delay of greater than 75mS, then it is essential that
a n auxiliary normally open contact on the main contactor is inserted in series with the RUN input on T31,
alterna tivel y use contactor wiring method shown in 4.3.2.
This will prevent the unit fr om trying to deliver power until the main contact has c losed.
6) A 3 phase line reactor must be in series with the A C supply, bet ween the contactor and po wer terminals.
This also helps to avoid main contactor mechanical operating shock being transmitted to PL /X busbars.
7) The phase rotation of the 3 phase supply is not important. However it is essential that there is pha se
equivalence for L1 to EL1, L 2 to EL2 and L3 to EL3. Particular care must be taken if L1/2/3 and EL1/2/3 are
fed from different sides of a transformer. If the transformer is star delta then there will be a phase mismatch
and the unit will fail to operate correctly. Only use star - star or delta - delta transformers.
8) For PLX units used in appli cations in which regeneration occurs for most or all of the time, it is
recomme nded to also fit a DC side semi-conductor fuse. Thi s will further protect the unit in the event of an
unsequenced power loss when regeneration is taking place.
9) All connections to control terminals 1 to 36 must be referred to earth.
10) If it is necessary to perform high voltage or diele ctric tests on the motor or wiring, then the drive unit
must be disconnected first. Failure to do so will invalidate warranty.
14.9.1 Wiring diagram for A C supply to L1/2/3 different to EL1/2/3. (E.g. Low voltage field)
It is not uncommon for the armature voltage and the field voltage of motors to be sufficiently different to
merit supplying them with different levels of A C voltage. This is particularly true for old motors.
The PL/X is provided with independent control bridges and supply inputs for the armature (L1/2/3) and field
(EL1/2/3). Normally the L1/2/3 and EL1/2/3 ports are fed with the same A C supply voltage, and if for
example, the field voltage is lower than w ould normally be expected for the prevai ling supply, then the
control loop will phase back the output voltage accordingly.
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