Measuring The Touch Current - Unitest Telaris 0751 Instruction Manual

6.4 Measuring the Touch Current

6.4.1 General Information regarding the
Touch Current
The touch current measurement for appliances
of protection class I may only be performed
after successful PE resistance test.
The UUT is put into operation during this test,
i.e. the UUT will be supplied with mains volt-
age. Therefore, the UUT must be switched on.
UUTs equipped with motor drives or with heat-
ing units may present a danger to the controller
(please observe the instruction manual of the
UUT!).
In compliance with DIN VDE 0701:2000-09,
the touch current measurement represents an
additional measurement to determine the in-
sulation properties for appliances of protection
class I and II. In compliance with DIN VDE
0702, this represents a substitute measure-
ment to the insulation measurement for appli-
ances of protection class II, for which the in-
sulation measurement may not or cannot be
performed.
TaTable 3 Limit Values
Touch current in compliance with DIN VDE 0701/0702, Part 1
Touch current in compliance with DIN VDE 0701/0702, Part 240
Measuring the Touch Current
The touch current measurement is performed
for appliances of protection class II with touch-
able, conductive parts or for appliances of pro-
tection class I, equipped with touchable, con-
ductive parts, not connected to the PE.
The measurement has to be performed for both
positions of the mains plug . The higher of both
values has to be considered. The UNITEST
TELARIS 0751 displays the
as a reference.
The touch current measurement using the
UNITEST TELARIS 0751 is performed by
means of the direct measurement procedure in
compliance with DIN VDE 0701/0702. The
UNITEST TELARIS 0751 measures the cur-
rent, flowing from the probe (2) to the PE con-
nector of the mains plug (1).
The limit value for the touch current in compli-
ance with DIN VDE 0701/0702 amounts to 0.5
mA. In compliance with DIN VDE 0701, Part
240, the limit value amounts to 0,25 mA. The
measurement has to be performed for both po-
sitions of the mains plug.
At measurements with faulty appliances or ap-
pliances with high leakage currents a preced-
ing RCD (Residual Current Device) could trip.
0,5 mA
0,25 mA
symbol (22)
31