Page 589 - Wago_Rail-MountedTerminalBlockSystems_Volume1_2015_US.pdf

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• Current-Carrying Capacity Curve (Derating Curve) to IEC/EN 60512-5-2
Both the design requirements and the connnector‘s current-carrying capacity must be checked by the user when selecting connec-
tors.
This data depends on the connected wire size, ambient temperature, number of simultaneously loaded poles, and connector‘s
internal resistance, as well as PCB layout and connector materials if required. In accordance with IEC/EN 60512-5-2, the rela-
tionship between current, ambient temperature and temperature rise up to the connector‘s upper temperature limit is illustrated via
current-carrying capacity curve (derating curve). The connector must only be operated up to this temperature limit (sum of the
self-generated heat and the ambient temperature) without being damaged or destroyed during operation.
Functioning of a current-carrying capacity curve (derating curve) according to EN 60512-5-2 is shown by an application using a
derating curve for the X-COM -SYSTEM: This application requires each pole of a 4-pole connector be subjected to a load of
®
32A. Based on the basic curve determined for this number of poles with a conductor cross-section of 4 mm², it has been deter-
mined the maximum ambient temperature is 42°C. The current must be reduced at higher ambient temperatures, e.g., to 19A at
an ambient temperature of 80°C.

Test current (A)

50
45 2-pole
40 4-pole
35 Rated voltage of the conductor 5-pole
30 6-pole
15-pole
25
20
15
10
5 1-conductor/
Ambient operating 1-pin carrier terminal block 769-176
0 temperature (°C)
0 10 20 30 40 50 60 70 80 90 100 Conductor cross section: 4 mm² “f-st” (AWG 12)
1-conductor female plugs 769-102 to 769-115
Conductor cross-section: 4 mm² “f-st” (AWG 12)
Conductor loop length: 1m

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