Different Power Supply Types - ABB AC 31 Technical Manual

1.5. Different power supply types

ABB Control - AC 31
1SBC 260400 R1001-b 06.99
Installation
The main differences between them concerns the connection of the neutral and the metallic
parts to the earth:
- T-T neutral: The neutral is connected to the earth. All the metallic parts are earthed
(see Figure 4-10).
- I-T neutral: The neutral is isolated in relation to the earth and the metallic parts are
earthed (see Figure 4-11).
Each cabinet (including the 24 V version), in a disturbed environment, should be fitted with an
isolated shielded transformer.
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