Figure 4-3 An Example Of Power Supply Wiring With An Isolation Transformer Mounted In The Programmable Controller Cubicle - Hitachi HSC-2100 Hardware Manual

4 WIRING
Case 2 -- an isolation transformer is mounted in the programmable controller cubicle:
Power supply:
100 to 120 VAC,
single phase, 50/60 Hz
Figure 4-3 An Example of Power Supply Wiring with an Isolation Transformer Mounted
in the Programmable Controller Cubicle
Note 1: The grounding metal piece must be electrically insulated from the programmable
controller cubicle.
Note 2: The mount base must be electrically insulated from the programmable controller
cubicle.
Note 3: The sizes of the cables used must be as follows:
Power cable: 2 mm
Ground wires: 2 mm
Power distribution panel
NFB
Cubicle ground
Class D grounding
Symbols: NFB, non-fuse breaker; TB, terminal block.
2
or more
2
or more in cubicle;
2
5.5 mm or more outside of cubicle.
Programmable controller cubicle
Isolation
NFB
transformer
TB
(collecting
LG wires)
Cubicle ground
(connected to
cubicle)
Cubicle ground
Class D grounding
4-4
H
LPU unit or
CPU unit
N
LG FG
H
I/O unit
N
LG FG
Grounding metal
piece (insulated
from cubicle)
Class D grounding
TB
(collecting
FG wires)