Bas
i
c app
li
cat
i
on
3 7
4.3 M
a
i
n
c
ont
ac
to
r
w
iri
ng opt
i
ons
There are var
i
ous w ays of
i
mp
l
ement
i
ng contactor contro
l
. Each method has advantages and d
i
sadvantages.
P
l
ease study the rest of th
i
s sect
i
on carefu
ll
y before choos
i
ng the contro
l
method.
See a
l
so 1 4.9.1 W
fferent to EL1/2/3. (E.g. Lo w vo
4.3.1 Ma
i
n contactor
i
so
l
at
i
ng A C stack supp
l
y
A dvantages
The aux
ili
ary supp
li
es are permanent
l
y energ
i
sed. Th
i
s a
ll
o w s the synchron
i
sat
i
on
c
i
rcu
i
ts to
l
ock onto the supp
l
y pr
i
or to the app
li
cat
i
on of po w er to the motor. Th
i
s resu
l
ts
i
n a fast re
l
ease of
current to the armature because
i
t avo
i
ds the synchron
i
sat
i
on de
l
ay. A
l
so the f
i
e
l
d can rema
i
n energ
i
sed after
contactor drop out, a
ll
o w
i
ng dynam
i
c brak
i
ng and/or condensat
i
on prevent
i
on
i
n standby f
i
e
l
d mode.
D
i
sadvantages
The f
i
e
l
d w
i
nd
i
ng
i
s not e
l
ectromechan
i
ca
ll
y
i
so
l
ated by the ma
i
n contactor, w h
i
ch
may contravene safety codes w
i
thout add
i
t
i
ona
l
measures. The f
i
e
l
d standby
l
eve
l
may not be set to a
l
o w
enough
l
eve
l
by the user and cou
l
d cause overheat
i
ng of the f
i
e
l
d w
i
nd
i
ng. Phase forw ard may occur before
contactor has c
l
osed caus
i
ng fau
l
t current. (T
i
me de
l
ay from ST ART command to phase forw ard
i
s 7 5mS.)
4.3.2 Ma
i
n contactor
i
so
l
at
i
ng A C stack and aux
ili
ary supp
li
es
A dvantages
The f
i
e
l
d w
i
nd
i
ng
i
s e
l
ectromechan
i
ca
ll
y
i
so
l
ated by the ma
i
n contactor. Some retro f
i
t
i
nsta
ll
at
i
ons are on
l
y ab
l
e to prov
i
de the 3 ma
i
n phases because the ma
i
n contactor
i
s remote
l
y
l
ocated to the
dr
i
ve pane
l
,
i
n w h
i
ch case th
i
s w
i
r
i
ng method may be preferred.
The PL/X cannot phase forw ard unt
il
the contactor has c
l
osed because EL1/2/3 take t
i
me to synchron
i
se.
Motor
Arm
L
i
ne
reactor
L1
L2
L3
EL1
EL2
EL3
Ma
i
n
Contactor
F-
F +
A ux
ili
ary
Fuses
Motor
F
i
e
l
d
Ma
i
n
Fuses
A +
A-
EL1/2/3 are w
i
red after the
ma
i
n fuses to ensure the
phase
l
oss funct
i
on w orks
i
f
a ma
i
n fuse b
l
o w s
D C Sem
i
conductor fuse for
regenerat
i
ve app
li
cat
i
ons
L
i
ne
reactor
L1
L2
L3
EL1
EL2
EL3
Ma
i
n
Contactor
F-
F +
A ux
ili
ary
Fuses
Motor
F
i
e
l
d
Ma
i
n
Fuses
Motor
Arm
A +
A-
D C Sem
i
conductor fuse for
regenerat
i
ve app
li
cat
i
ons
Summary of Contents for PLX
Page 2: ...2 Contents ...
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