BD01 System – 40 ... 160 A - GRUP DAP

© Siemens AG 2007
Appendix
Glossary
Interlock of opposing contacts
(see also IEC/EN 60947-1; 2.4.11 / IEV 441-16-12)
Isolating function
(see also IEC/EN 60947-1; 2.1.19)
Losses
(see also IEV 151-03-18)
Mechanical shock resistance
Minimum command time
Opening delay
(see also IEV 441-17-36)
Overvoltage category
(see also IEC/EN 60947-1; 2.5.60)
Pollution degree
(see also IEC/EN 60947-1; 5.5.58)
Positive opening
(see also IEC/EN 60947-1; 2.4.10 / IEV 441-16-11)
This ensures that the auxiliary contacts of a switching device are
always in the switching position corresponding to the open or closed
position of the main contacts. The contacts of contactors are interlocked
opposing contacts, provided they are mechanically linked in
such a way as to ensure that normally closed contacts and normally
open contacts can never be closed simultaneously. This arrangement
must also ensure that minimum contact separation of 0.5 mm is maintained
over the entire endurance of the device, even during a fault
(e.g. welding of one contact). The pertinent German Trade Association
requires the use of contactors with interlocked opposing contacts for
control systems on power presses in the metal processing industry.
Equipment is deemed to possess this isolating function provided their
switching contacts, when in the open position, achieve the separation
distance prescribed for the isolation of electrical circuits, and their
creepage paths and clearance distances are of the required size. The
power supply to the entire installation or a section of the installation can
thus be cut off for safety reasons, e.g. during maintenance.
The difference between the input power and the output power of a
device. The main type of loss in electrical equipment and operating
media in power distribution is current heat loss.
The capacity of an equipment to withstand pulse-like motions without
changing its operating status or sustaining damage. No contact lifting
must take place on devices in the On position, the main contacts must
not knock against one another in the Off position. A protective switch
must not trip, and control circuit switches must not change their switching
status.
Minimum period of time for which a trip-initiating factor (control pulse,
short-circuit current) must be present in order to effect the corresponding
reaction, e.g. the short-circuit duration necessary to initiate tripping.
The interval of time between the specified instant of initiation of the
opening operation and the instant when the arcing contacts have separated
in all poles. The opening delay is the sum of the tripping delay
and the inherent delay of the contacts.
Conventional number for prospective overvoltages as might be
caused, for example, as a result of lightning or switching processes.
The overvoltage category applicable to industrial switchgear is III. The
applicability of switchgear according to the overvoltage categories is
as follows:
• Overvoltage category IV:
Use directly at the termination point of the installation (directly affected
by any lightning), e.g. at an overhead line connection point.
• Overvoltage category III:
Operating media with special requirements as to the serviceability for
connection in fixed installations which are protected by overvoltage diversion
measures, e.g. switches in low-voltage distribution systems or
in control systems for industrial use.
• Overvoltage category II:
Power consumers for connection to fixed installations, e.g. household
appliances, electrical tools.
• Overvoltage category I:
Operating media for connection to circuits with overvoltage protection
schemes, e.g. electronic devices.
Conventional number for the prospective quantities of conductive dust
and humidity, which can lead to a reduction in the control circuit reliability
of a switching device. The pollution degree is defined by the following
factors:
• Pollution degree 1:
No pollution or only dry, non-conductive pollution occurs. The pollution
has no effect on the control circuit reliability.
• Pollution degree 2:
Usually, only non-conductive pollution. However, transient conductivity
through condensation is to be expected.
• Pollution degree 3: (switchgear for industrial use)
Conductive pollution or dry, non-conductive pollution, which is rendered
conductive through condensation.
• Pollution degree 4:
The pollution leads to long-term conductivity, e.g. pollution through
conductive dust, rain or snow.
An opening operation which ensures that the main contacts of a switching
device have attained the open position when the actuator is in the
Off position.
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