Page 592 - Wago_Rail-MountedTerminalBlockSystems_Volume1_2015_US.pdf

14 Tests and Testing Procedures per IEC/EN Standards (continued)

590 Electrical Tests (continued)

• Insulation Parameters to IEC/EN 60664-1
Clearances and Creepage Distances Overvoltage categories for electrical equipment:
The following generally applies: A specific overvoltage category must be defined on the basis of the following, gener-
The equipment specification contains al description:
data for the measurement of clearances – Equipment in overvoltage category I is intended to be connected to the fixed
and creepage distances, or refers to the electrical installations of buildings. Protective means are taken outside the equip-
data contained in the basic standard DIN ment – either in the fixed installation or between the fixed installation and the
EN 60664-1/VDE 0110, part 1. equipment – to limit transient overvoltages to the specific level.
DIN EN 60664-1/VDE 0110, part 1, – Equipment in overvoltage category II is to be connected to the fixed electrical
contains the clearances and creepage installations of buildings.
distances in compliance with insulation Note: Examples of such equipment are household appliances, portable tools and
coordination requirements. That is, the similar loads.
insulation parameters of equipment are – Equipment in overvoltage category III is part of the fixed electrical installations
assigned to: and other equipment where a higher degree of availability is expected.
Note: Examples of such equipment are distribution boards, circuit breakers, wiring
– the anticipated surge voltages, systems (IEV 826-06-01, including cables, bus-bars, junction boxes, switches, sock-
– the parameters of the protection device et-outlets) in the fixed installation and equipment for industrial use and other equip-
against surge voltage ment, e.g., stationary motors with permanent connection to the fixed installation.
– the anticipated environmental condi- – Equipment in overvoltage category IV is for use at or in the proximity of the ori-
tions and the protection measures gin of the electrical installations of buildings upstream of the main distribution
against pollution. board.
Note: Examples include electricity meters, primary overcurrent protection devices
This standard is based on and ripple control units.
IEC 60604-1.

Clearances, Rated Surge Voltages, The rated surge voltage shall be selected from Table 1 corresponding to the overvolt-
Overvoltage Categories, Pollution age category specified and to the rated voltage of the equipment.
Degrees Table F.1- Rated surge voltage for equipment energized directly from the low-voltage
mains (DIN EN 60664-1/VDE 0110, Part 1)
Surge voltages (table 1) are a decisive 1 Voltage curve: 1.2/50 µs per IEC60060-1/VDE 0432, Part 1.
factor in determining air distances.
Nominal voltage of Voltage line to neutral Rated surge voltage 2)
The basis forms the overvoltage cate- the supply system 1) derived from nominal
gory, i.e., the allocation of the equip- (mains) based on IEC 60038 3) voltage a.c. or d.c. up to
ment to the expected surge voltage, and and including Overvoltage category 4)
the conductor-ground voltage derived
from the rated line voltage in installations
Three-
Single-
with a grounded Y (star) point. phase V phase V V V I II III IV
V
V
V
50 330 500 800 1500
In ungrounded installations, or installa-
tions where the conductor is not ground- 100 500 800 1500 2500
ed, the voltage between conductors is 120-240 150 5) 800 1500 2500 4000
applicable in the same way as conductor
voltage to ground. 230/400 277/480 300 1500 2500 4000 6000
1 Voltage pulse 1.2/50 400/690 600 2500 4000 6000 8000
1000 1000 4000 6000 8000 12000
1) See Annex B for application to existing different low-voltage mains and their nominal voltages.
2) Equipment with these rated overvoltage levels can be used in installations in accordance
with IEC 60364-4-443.
3) The / mark indicates a 4-wire three-phase distribution system. The lower value is the voltage line-to-neutral,
% u
100 while the higher value is the voltage line-to-line. Where only one value is indicated, it refers to 3-wire,
90 three-phase systems and specified the value line-to-line.
4) See 4.3.3.2.2 fo an explanation of the overvoltage categories.
50 û 5) The nominal voltages for single-phase systems in Japan are 100V or 100 - 200V.
30 The value for the rated surge voltage is, however, derived from the voltage gaps line-to-neutral
0 for a voltage level of 150V (see Annex B)
T
T 1 =1.2 µs
T 2 = 50 µs
The nominal supply voltage and the corresponding rated surge voltage values apply
acc. to EN 61180-1 / VDE 0432, Part 10 for grounded and ungrounded circuits.