Power Supply System Requirements - ABB IRC5 Product Manual

2 Installation and commissioning

2.5.2 Power supply system requirements

2.5.2 Power supply system requirements
Definition of the power supply system
IEC 60364 defines three different types of mains grounding using the two-letter
codes. These are TN, TT, and IT.
First letter
T
I
Second letter
T
N
In the following section the transformer configuration refers to the transformer
secondary side. Configuration of the transformer primary side is not discussed in
this context.
Recommended power supply systems
The following systems are recommended by ABB:
TN−S system
PE and N are separate conductors that are
connected together only near the transformer.
xx1700001310
Not recommended power supply systems
The following systems are not recommended by ABB:
TT system (separate ground rods)
If this kind of system must be used, the
grounding path resistance between ground
1 and 2 shall not exceed 0.1 Ohm, for more
information refer to UL1740.
Continues on next page
64
Type of ground connection
Direct connection of one point to ground.
Not connected to ground or connected to ground via a high impedance.
Connection between ground and the device being supplied
Direct connection of one point to ground.
Direct connection to neutral at the origin of installation, which is connec-
ted to the ground
L1
L2
L3
N
PE
© Copyright 2007-2024 ABB. All rights reserved.
TN−C system
A combined PEN conductor is used as both
a PE and an N conductor.
xx1700001311
Resistance grounded secondary system
If this kind of system must be used, the
voltage variations between any line and PE
should not exceed ±10% of the nominal line
voltage, for more information refer to EN
50160.
Product manual - IRC5 Panel Mounted Controller
3HAC047137-001 Revision: AB
L1
L2
L3
PEN