Guidelines For Fuses/Circuit Breakers; Fusing The Controller And Remote I/O Base; Figure 2-4 Fuse/Circuit Breaker Placement - Siemens SIMATIC TI555 System Manual

2.4

Guidelines for Fuses/Circuit Breakers

Fusing the
Controller and
Remote I/O Base
TI545/TI555 System Manual
Use the following guidelines for installing fuses/circuit breakers; see
Figure 2-4. The sizes and types of fuses/circuit breakers depend on the
specified power distribution requirement.
A circuit breaker before isolation transformer (isolation transformers
may not be required if your power distribution system does not have a
high level of noise).
A fuse after isolation transformer.
An external fuse before each power supply.
Input Power Line 110/220 VAC

Figure 2-4 Fuse/Circuit Breaker Placement

NOTE: In order to ensure a proper level of safety compliance, observe local
installation code practices and guidelines.
Isolation
Transformer
Optional
Grounds
P/S
(Line)
(Neutral)
(Ground)
P/S
(Line)
(Neutral)
(Ground)
Controller
Remote I/O Base
Pre-installation Guidelines
2-7