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12 Posts in this encyclopedia categoryDevice service life
Mechanical service life indicating the permissible number of switching operations with de-energised relay contacts.
DGUV Regulation 3
A prerequisite for the safe, fault-free operation of electrical
systems and equipment is the permanent assurance of their proper
condition. The types of tests and test intervals required for this are
specified in the accident prevention regulation DGUV Vorschrift 3
(formerly BGV A3). Corresponding implementation instructions (DA) help
to achieve the protection goals.The types of inspection include:Visual inspection for externally visible defectsTesting and measuring protective measures, insulation resistance and loop resistanceFunctional testThe test results must be documented, e.g. by means of a test report.Further information can be found here Always be documented, e.g. by means of a test report.Further information can be found here
Diagnostic Coverage (DC)
Diagnostic coverage represents the ratio of the failure rate of noticed
dangerous failures and failure rate of total dangerous failures.
Differential current monitor
Differential current monitors, also called RCMs (residual current
monitors), are used in earthed networks (TN networks). Here, residual
current monitoring is carried out according to the principle of residual
current measurement and primarily serves to avoid expensive downtimes
and to prevent fire hazards that are latent due to creeping insulation
faults. The residual current measurement is carried out via the external
residual current transformer. However, integrated residual current
transformers are also available from Dold. This guarantees a higher
level of operational and system safety. Insulation monitors are used for
insulation monitoring in unearthed systems.
DIN EN 61508
DIN EN 61508 considers the safety-related functions over the entire
life cycle of a product / system from design to decommissioning
(probabilistic aspects). It is a basic safety standard from which
industry-specific or sector-specific standards, such as DIN EN 61511 for
the process industry, DIN EN 61513 for nuclear power plants or DIN EN
62061 for the mechanical engineering industry, are derived.
DIN EN 62061
Functional safety of safety-related electrical, electronic and
programmable electrical control systems. Application-specific sector
standard for the mechanical engineering industry. The requirements for
safety-related performance relevant to the application area of machine
safety in DIN EN 61508 are concretised in DIN EN 62061 with regard to
significant hazards of machines.
DIN EN ISO 13849
Safety of machinery - Safety-related parts of control systemsPart 1: General design principlesPart 2: Validation
Discrepancy monitoring
Tolerates the non-simultaneity of related signals through a defined
time window. The term simultaneity monitoring is also used. Monitoring
of signal transmitters is used to increase functional safety. It is
carried out by checking the signal change of the sensors within the
specified time. If this time is exceeded, no enable signal is given.
Such monitoring is mandatory for some safety devices (two-hand control).
Distributor housing
The distribution boxes meet all requirements in the field of modern
building automation. The distribution boxes have an installation depth
of 70 mm and 55 mm and a width of 8.8 to 140 mm. They are suitable for
installation in distributions according to DIN 43 880. A major highlight
is their variable connection technology.All common connection
technologies, including heavy-current terminals with a current-carrying
capacity of up to 40 A and a connection cross-section of up to 10 mm²,
are available and can be combined in one distribution enclosure. The
changeable front can be selected in crystal clear or grey. BUS and EIB
connections and individual enclosure openings, e.g. ventilation slots or
cut-outs for LEDs, potentiometers or displays, can be integrated on
request. Accessories such as suitable knobs for potentiometers and light
guides for LEDs can also be easily ordered.
Drive monitoring
The speed monitors of the SAFEMASTER S series detect and signal the
standstill and speed of machines and systems in automatic as well as in
set-up mode. Dold offers efficient and economical solutions for safe
sensorless drive monitoring as well as speed monitoring via proximity
switches.
Drying
The relays can be dried in a stream of warm air at a temperature of
approximately 50 °C. To speed up the drying process, the relays can be
blown off with a jet of compressed air at max. 1.5 bar, which also
removes the residues of the washing medium located between the relay
base and the PCB.