Gossen MetraWatt 702 - Manual (Page 12)

12 GOSSEN METRAWATT GMBH
5 Classification of Devices Under Test
5.1 Safety Classes
Devices assigned to all of the following safety classes are equipped with
basic insulation, and provide for protection against electrical shock by
means of various additional precautions as well.
Safety Class I Devices
Exposed, conductive parts are connected to the protective conductor so
that they are not charged with voltage if the basic insulation should fail.
Safety Class II Devices
These devices are equipped with double insulation or reinforced
insulation.
Safety Class III Devices
These devices are powered with safety extra-low voltage (SELV). Beyond
this, no voltages are generated which exceed SELV. These devices may
not be connected to the mains.
Note: The DUT may only be connected to the test instrument at jacks 1
through 3 (Feature F01). Only a visual inspection, an insulation resistance
measurement or a measurement of the supply voltage can be performed,
see parameter “SC III U
V
” on page 27.
Parameter Classification (in the Sequence... menu)
The SECUTEST
®
SII always tests in accordance with the strictest limit val-
ues of the respectively selected safety class. The test is failed if this limit
value is exceeded. However, devices under test exist for which higher limit
values are allowable.
If parameter classification is activated (= x), the user is asked if higher limit
values are allowable for the DUT. If “Yes” is entered, reevaluation ensues
and the DUT may pass the test.
Examples
If the insulation resistance test is failed, or if interference suppression
capacitors have been replaced, equivalent leakage current measurement
must be performed on DUTs with heating elements in accordance with
DIN VDE 0702.
The test is failed by a DUT with 300 kW with deactivated classification
function (= _), but it is passed with activated classification function (= x) if
the question is answered accordingly.
Similar possibilities for passing the test, although it might otherwise be
failed, are included in DIN VDE 0701, part 1.
If the DUT is connected via the jacks instead of the test socket, other limit
values apply because higher power consumption is possible in this case
(e.g. part 1 specifies a limit value of 1 mA per kW for equivalent leakage
current).
See also table: “Maximum Allowable Limit Values for Equivalent
Leakage Current in mA” on page 20.
5.2 Application Parts (electrical medical devices)
Type B Application Parts (body)
Devices of this type are suitable for both internal and external patient
applications, except for use in direct proximity to the heart.
These devices provide for adequate protection against shock especially
as regards:
• Reliable leakage current
• Reliable protective conductor connection if utilized
Devices of the following safety classes are allowable: I or II.
Type BF Application Parts (body float)
Same as type B, but with type F insulated application parts.
Type CF Application Parts (cardiac float)
Devices of this type are suitable for use directly at the heart. The
application part may not be grounded.
Devices of the following safety classes are allowable: I or II.