Benning ST 755+ - Contact Current of the Welding Circuit; Prcd

Functions
7.7 Individual tests
5284 / 08/2023 en BENNING ST 755+ / ST 760+ 47
The device uses a digital potentiometer to realise the load of the welding device. The load starts
as soon as at least half of the limit of the welding voltage has been reached. The load duration
is 3seconds.
The device measures the AC or DCwelding voltage, the peak value of the welding voltage and
the welding current between the two poles.
7.7.11 Contact current of the welding circuit
EN50678 (VDE0701)
EN50699 (VDE0702)
EN62353
(VDE0751‑1)
EN60974‑4
(VDE0544‑4)
ClassI ClassII ClassIII ClassI ClassII ClassI ClassII
- - - - - X X
The contact current of the welding circuit is tested to check for compliance with the rated values
of devices according to VDE0544‑4 [}page94].
For this purpose, the following measuring methods may be used:
• Direct current measuring method (direct measuring method)
• Differential current measuring method
• Alternative leakage current measuring method
7.7.12 PRCD
EN50678 (VDE0701)
EN50699 (VDE0702)
EN62353
(VDE0751‑1)
EN60974‑4
(VDE0544‑4)
ClassI ClassII ClassIII ClassI ClassII ClassI ClassII
X - - - - - -
A portable residual current protection device (PRCD) provides protection against hazardous
body currents in the downstream circuit in case of direct contact. The rated value for the tripping
fault current is max.30mA [}page95].
The device provides an automatic test procedure [}page104] for each PRCDtype. The
PRCDtest includes the following tests and measurements:
PRCD
type
A F B B+ K S S+ AC 2-pin 3-pin
Tripping type AC/
pulsating
direct currents
DC/
universal
current-
sensitive
AC
Tests
Tripping current at
0° and 180°
Tripping times
X X X X X X X X X X
X X X X X X X X X X
V
Cont
X X X X X X X X X X
Tapping the TRIP
key
X X X X X X X X X X
Interrupting the
Lconductor
X X X X X
Interrupting the
Nconductor
X X X X X
Interrupting the
PEconductor
X X X X