ABB ACH580-01 Series, Руководство по оборудованию

Страница: 173 / 396

Electrical installation – North America 173
UL
NEC
Note:
• ABB does not guarantee the EMC category because the EMC filter screws have
been disconnected.
• ABB does not guarantee the functioning of the ground leakage detector built
inside the drive.
• In large systems the residual current device can trip without a real reason.

Identifying different types of electrical power systems
To identify the electrical power system type, find out the supply transformer
connection. If that is not possible, measure these voltages at the distribution board
before you connect power to the drive:
1. input voltage line to line ( U
L-L
)
2. input voltage line 1 to ground ( U
L1-G
)
3. input voltage line 2 to ground ( U
L2-G
)
4. input voltage line 3 to ground ( U
L3-G
).
The line-to-ground voltages in relation to the line-to-line voltage of the electrical
power system types are shown below. See the diagrams on page
171 .
U
L-L
U
L1-G
U
L2-G
U
L3-G
Electrical power system type
X 0.58·X 0.58·X 0.58·X Symmetrically grounded TN system
(TN-S system)
X 1.0·X 1.0·X 0 Corner-grounded delta system (non-
symmetrical)
X 0.866·X 0.5·X 0.5·X Midpoint-grounded delta system (non-
symmetrical)
X Varying level
versus time
Varying level
versus time
Varying level
versus time
IT systems (ungrounded or high-
resistance-grounded [>30 ohms]) non-
symmetrical
X TT system (the protective earth
connection for the consumer is
provided by a local earth electrode, and
there is another independently installed
at the generator.