YASKAWA VS-505WII - Page 13

Thyristor Protective
Fuse Replacement
VS -505W 1, 230 V at 180 to 550 A, 460 V at
180
to 550 A
1 . Remove
the two lead clamping screws of the
fuse-blown indicating mocroswitch and free
the leads .
(Fig
. 20)
2 . Remove the two
fuse mounting bolts, and
remove the fuse together
with
the
fuse-blown
indicating microswitch .
3 . Check the replacement
fuse for model and
capacity, and install it by reversing the disas-
sembling procedure .
Surge Absorber
Fuse Replacement
Surge Absorber Replacement
Fig . 20 Main Circuit FuseAssembly
(460 V, 420 A)
1
.
Pull
the fuse
element and remove it . (Fig . 21)
2 . Mount the
replacement fuse, after checking
its model and capacity .
Fig . 21
Surge Absorber Fuse
1 . Remove three
surge absorber mounting
screws
and remove surge
absorber .
2 . Check the
replacement surge absorber for
model and capacity . Mount three surge
ab-
sorbers after connecting M4 pressure termi-
nals to their leads
as shown in
Fig . 22 .
IL
)k,
Thyristor Cooling
Fan Replacement
Fig . 22 Surge
Absorber with Pres-
sure Terminals
Connected to Leads
To replace a thyristor cooling fan with a new one,
proceed as follows
.

(Fig . 23) The VS-505WIL
units

rated 230 V, 25 A ; 460 V, 50
A
are
self-
cooled type .
1 .

Remove the cooling fan power lead .
2 . Unscrew the two fan mountingscrews and
dismount the fan .
3 . Remove the fan by reversing the disassembl-
ing procedure .
(a) 230 V, 45 to 105
A ; 460 V, 90/105 A
FAN
POWER SUPPLY
LEADS (2)
r
. .
(b)

230 V, 180/260 A ; 460 V, 180/260 A
(c)

230 V, 420/550 A ; 460 V,
420/550 A
Fig .
23 Thyristor Cooling Fan
1 3