– 7 –
[Changing over the voltage between 100 V and 200 V]
WARNING :
To prevent personal injuries caused by electric shock hazards or abrupt start of the sewing machine,
carry out the work after turning OFF the power switch and a lapse of 5 minutes or more. To prevent
accidents caused by unaccustomed work or electric shock, request the electric expert or engineer of
our dealers when adjusting the electrical components.
By making the following two changes, the SC-921 can
be used with three different power supplies, i.e., single-
phase 100 - 120 V, single-phase 200 to 240 V and
3-phase 200 to 240 V.
* Only the control box which uses PWR-T PCB can
be changed.
1
Replacement of the power cords
2
Changing-round of connector
1
on the PWR PCB
1) Turn OFF the power with the power switch after
checking that the sewing machine has stopped.
2)
Draw out the power cord from the power receptacle
after checking that the power switch has been turned
OFF. Then wait for 5 minutes or more.
3) Loosen the screws which are used to secure the
rear lid of the control box cover. Carefully open the
rear cover.
4) Changing procedure of the power voltage
(Caution) If the supply power changing is carried
out in a wrong manner, the control box can
break. Be extremely careful when taking the
supply voltage changing procedure.
A. To change over the supply voltage from 200 - 240 V
to 100 - 120 V
¡
Change the power cord with the JUKI genuine cord
with the part number (M90355800A0). Change
the earth cord with the one with the part number
(M90345800A0).
¡
Change over supply voltage changeover connector
1
mounted on the PWR PCB with the connector for 100 V.
¡
Connect the crimp style terminal of AC input cord to
the power plug as shown in the gure A.
B,C. To change over the supply voltage from 100 - 120
V to 200 - 240 V
¡
Change the power cord with the JUKI genuine cord
with the part number
(
M90175800A0).
¡
Change over supply voltage changeover connector
1
mounted on the PWR PCB with the connector for 200 V.
¡
Connect the crimp contact of the AC input cord to the
power plug as illustrated in Fig. B for the 3-phase power
supply or as illustrated in Fig. C for the single-phase one.
5) Before closing the rear lid of the cover, ascertain again
that the relevant parts have been correctly changed
without fail.
6) Close the read lid while pressing it, taking care not to
allow the wiring to be caught between the read lid of
the cover and the main body of the control box. Then,
secure the lid with the screws.
1
1
2
3
Wiring for the 3-phase 200 V
A
B
C
* The illustration below shows the PWR-T PCB.
The type of PCB differs by destination.
(Plug side)
WHITE
BLACK
RED
GREEN/
YELLOW
WHITE
BLACK
GREEN/
YELLOW
(Plug side)
WHITE
BLACK
RED
GREEN/
YELLOW
WHITE
BLACK
RED
GREEN/
YELLOW
(Plug side)
WHITE
BLACK
RED
GREEN/
YELLOW
GREEN/
YELLOW
1
2
3
WHITE
BLACK
Wiring for the single-phase 100 V
Be sure to connect the wire between 1 and 2.
If it is connected between 1-3 or 2-3, the sewing
machine will be inoperative.
Wiring for the single-phase 200 V
Be sure to connect the wire between 1 and 2.
If it is connected between 1-3 or 2-3, the sewing
machine will be inoperative.
(Caution) Be sure to remove the
connector while holding its
locking section with your
ngers. Be extremelycare-
ful not to pull the connector
forcibly.
Locking section
(Box side)
(Box side)
(Box side)
1
2
3