Page 598 - Wago_Rail-MountedTerminalBlockSystems_Volume1_2015_US.pdf

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

596 Electrical Tests (continued)

• Power-Frequency Withstand Voltage Test to IEC/EN 60998-1
This test procedure verifies creepage distances. Creepage distances, i.e., the distances of creeping currents, are caused by con-
ductive impurities on the surface of the insulation housing. Apart from the amount of impurities to which a terminal block is sub-
jected, for example, the plastic material and housing design are also involved in generating creeping currents. The insulation
material of the housing may be carbonized by a creeping current, which increases conductivity even more.
The specimen is tested using a power-frequency withstand voltage for a short time. For example, a rail-mounted terminal block
designed to operate at 800V nominal voltage is usually tested using 2000V alternating voltage for one minute. The test is consid-
ered to be passed if no flashovers or breakdowns have occurred.

• Rated Impulse Withstand Voltage Test to IEC/EN 60664-1
This test verifies the clearances of a product. In simplified terms, a clearance is the distance between two poles of a terminal
block. If this distance is too small, voltage peaks may cause flashovers or breakdowns. The arrangement of the rated impulse
withstand voltage test is identical to that of the power frequency withstand voltage test; the test voltages, however, are compara-
tively higher and the testing times shorter, e.g., 7.3kV over 50µs (see figure).

Voltage pulse; measurement curve (red) and auxiliary curve (black) for calculating
% u
100 the rate of rise of the pulse and the resulting (virtual) peak of the curve.
90
50 û T Time interval for calculating the rate of rise
30 T 1 Front time (duration between start of impulse and reaching the peak)
0 T 2 Total pulse duration
T
T 1 =1.2 µs
T 2 = 50 µs
The test values are the values at sea level as specified in the relevant test specification.
The values indicated in the catalog correspond to an altitude of 2000m.
The test is considered to be passed if no flashovers or breakdowns have occurred.

• IP Ratings for Electrical Equipment to IEC/EN 60529
Alphanumeric nomenclature for type of protection
Code letters Protection against touch and solid IP (Ingress Protection)
IP objects or water
First digit Indicates degrees of protection against If indicating the degree of protection requi-
0 to 6 touch or solid objects. res only one digit, the other (second) digit
Second digit Indicates degree of protection against must be substituted for with an X.
0 to 8 water.
First digit: Second digit:
IP0X No protection against touch, IPX0 No protection against water
or solid objects IPX1 Protected against vertically IP vs. NEMA
IP1X Protected against solid objects > 50 mm falling water
IP2X Protection against solid objects > 12 mm IPX2 Protected against dripping IP Code NEMA
(e.g. finger) water - 15° angle 10 1
IP3X Protected against solid objects > 2.5 mm IPX3 Protected against water spray 11 2
IP4X Protected against solid objects > 1 mm IPX4 Protection against water splash 54 3
IP5X Dust-protected (limited ingress, no IPX5 Protected against water jet, 14 3R
harmful deposits) e.g., from a nozzle 54 3S
IP6X Dust-tight (totally protected against dust) IPX6 Protected against flooding 55 4&4X
IPX7 Protected against temporary 52 5
immersion 67 6&6P
IPX8 Protected against continuous 52 12&12K
immersion 54 13