8
Installation
Check that the instrument operating voltage marked on the rear panel is suitable for the local
supply. Should it be necessary to change the operating voltage, proceed as follows:
1) Disconnect the instrument from all voltage sources.
2) Remove the screws which retain the top cover and lift off the cover.
3) Change the connections on both transformers following the appropriate diagram below:
BROWN
BLUE
BROWN
BLUE
BROWN
115V
230V
4) Refit the cover and the secure with the same screws.
5) To comply with safety standard requirements the operating voltage marked on the rear panel
must be changed to clearly show the new voltage setting.
6) Change all three fuses to ones of the correct rating, see below.
Fuse
The AC inlet fuse is located in the fuse drawer in the lower part of the IEC inlet connector. To
change the fuse remove the line cord and open the fuse drawer with a suitable tool.
QL355, QL355P, QL564 & QL564P
The correct mains fuse type is 20 x 5mm 250V HBC time-lag with the following rating:
for 230V operation:
1.6A (T) 250V HBC
for 115V operation:
3.15A (T) 250V HBC
QL355T, QL355TP, QL564T & QL564TP
The correct mains fuse type is 20 x 5mm 250V HBC time-lag with the following rating:
for 230V operation:
4A (T) 250V HBC
for 115V operation:
8A (T) 250V HBC
In addition, the two transformers are individually fused inside the power supply. To access these
fuses remove the cover as described above; both fuses are clipped to the small PCB which is
fitted directly onto the pins of the IEC inlet connector itself.
The correct fuse type is 20 x 5mm 250V HBC time-lag with the following rating:
for 230V operation:
1.6A (T) 250V HBC
for 115V operation:
3.15A (T) 250V HBC
Make sure that only fuses with the required current rating and of the specified type are used for
replacement. The use of makeshift fuses and the short-circuiting of fuseholders are prohibited.
