Page 618 - Wago_PCB_TerminalBlocksConnectors_Volume2_2015_US

General Technical Information
13 on Electrical Equipment Used in Hazardous Areas (continued)
616
It is expressly prohibited to use insulating Table 1: Creepage Distances and Clearances
parts for transferring contact forces!
Terminal blocks with sharp edges which Voltage Minimum creepage distance Minimum clearance
1)
could damage supply lines and those RMS value for mm mm
types that can be rotated, turned or per- AC voltage Material group
manently deformed when fixed in place or DC voltage
are not permitted for use. Terminal blocks V I II III a
for internal connections in electrical 10 2) 1.6 1.6 1.6 1.6
equipment must not be subjected to 12.5 1.6 1.6 1.6 1.6
1.6
1.6
16
1.6
1.6
excessive mechanical stress. These items 20 1.6 1.6 1.6 1.6
must fulfill the requirements for terminal 25 1.7 1.7 1.7 1.7
blocks used for external electrical con- 32 1.8 1.8 1.8 1.8
ductors. 40 1.9 2.4 3.4 3 1.9
2.1
2.1
50
2.6
Clearances between conductive parts 63 2.1 2.6 3.4 2.1
having different potentials must be at 80 2.2 2.8 3.6 2.2
3
least 3 mm for external connections, as 100 2.4 3.2 3.8 4 2.4
2.5
125
2.5
specified in Table 1. 160 3.2 4 5 3.2
200 4 5 6.3 4
Creepage distances depend on the oper- 250 5 6.3 8 5
10
8
320
ating voltage, surface geometry of the 400 (440)* ) 6.3 8 10 12.5 6
6
insulating parts and tracking resistance of 500 (550)* ) 10 12.5 16 8
the insulating material. 630 (690)* ) 12 16 20 10
Grooves on the surface may only be con- 800 16 20 25 12
sidered if they are at least 2.5 mm deep 1000 20 25 32 14
18
1250
32
26
22
and wide; ribs on the surface only if their 1600 23 27 32 20
height is at least 2.5 mm and their width 2000 25 28 32 23
corresponds to the mechanical strength 2500 32 36 40 29
3200
36
40
50
45
of the material, however not smaller than 4000 50 56 63 44
1 mm. 5000 63 71 80 50
6300 80 90 100 60
8000 100 110 125 80
10000 125 140 160 100
1) The voltages given here are taken from IEC 60664-1. The working voltage *) may not exceed the voltage level
given in the table by more than 10%. This is based on reduction of the supply voltages in accordance with Table
3b in IEC 60664-1.
The listed values for creepage distances and clearances are based on a maximum limit deviation for supply volt-
age of ± 10 %.
2) The CTI value does not apply for 10 V and values below this, and materials that do not fulfill the requirements set
forth by material group IIIa may also be used.
Classification of insulating materials Table 2: WAGO PCB terminal blocks fulfill this
according to their tracking resistance is Tracking Resistance for requirement.
made on the basis of their comparative Insulating Materials According to EN 60069-7/DIN VDE
tracking index (CTI) and is defined in 0170, Part 6, connecting electrical equip-
Table 2 as follows: ment to terminal blocks having an
This classification applies to insulating Material Comparative increased safety “e” protection type must
parts without ribs or grooves. group tracking index not lead to a reduction of the clearances
If the insulating parts have ribs or and creepage distances.
grooves sufficiently large to be consid- I 600 ≤ CTI Based on experience gained with use of
ered, the minimum creepage distances II 400 ≤ CTI < 600 equipment in aggressive atmospheres in
must be set according to values for the III a 175 ≤ CTI < 400 the chemical industry, we recommend
insulating materials in the next-higher lev- using either gas-tight crimped, tinned cop-
el, for example Group I, instead of per ferrules or tinned pin terminals made
Group II. Conductor Types and of copper with fine-stranded conductors
Considering the ambient temperature of Conductor Preparation for connection of terminal blocks in corro-
40 °C (104 °F) specified for electrical In accordance with EN 60079-14/DIN sive atmospheres.
equipment, the current-carrying capacity VDE 0165-1, the ends of stranded and
of rubber-insulated conductors is reduced fine-stranded conductors must be protect-
to 82 %, based on DIN VDE 0298-4: ed against splaying (e.g., via cable lugs
2003-08, Table 10 and to 87 % for PVC- or ferrules) or by the type of terminal
insulated conductors for the current-carry- blocks used. Soldering alone is not suffi-
ing capacity defined for 30 °C (86 °F) cient.
in accordance with Item 4.3.3 in DIN The conductor introduction funnels of
VDE 0298-4: 2003-08.