82.031.0101.0 WIELAND ELECTRIC, 82.031.0101.0 Datasheet - Page 442

• Manufacturer Part Number: 82.031.0101.0
• Description: COUPLING MODULE
• Manufacturer: WIELAND ELECTRIC

Specifications of 82.031.0101.0

• Connector Type: Modular
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

flare
To avoid harmful discharge processes, it is
necessary to prevent a sudden disruption
in the flow of current and simultaneously
ensure that the voltage rise at the contact,
which is limited by the degradation of the
magnetic field, takes place at a slower rate
than the opening of the contact. This
counteracts the occurrence of a discharge
process and an air gap is therefore created
as quickly as possible after the opening of
the contact whose igniting voltage far
exceeds the voltage building up at the
contacts. An RC element which lies
parallel to the contact can also be used for
this purpose.
RC element for inductive load
When the contact opens, a charging
current which is subsiding after an e
function, flows into the capacitor. This
slows down the absorption of the current
that is flowing through the inductor and
the peak value of the voltage at the
contact is simultaneously reduced. The
following serves as a practical,
approximate value for the rating of the
capacitor
C ( F)
where I represents the respective
switching current. The resistance must be
rated so that the combined total of the
capacitor discharge current and the
switching current is again less than the
permitted starting current.
Another possibility is the parallel
connection of an RC element to the load
itself (see diagram above). This protective
measure is equally effective. The
disadvantage of both arrangements is the
use of relatively large and therefore
expensive capacitors.
RC circuit for a.c. load
A VDR resistor (Voltage Dependent
Resistor) or varistor can be connected in
parallel to the load in this application in
order to protect the contact. The
resistance of this component is low for
high voltage levels and high for low
voltage levels. Varistors are therefore
extremely suitable for the suppression of
arcs in a.c. circuits. Table 2 gives an
overview of further possibilities for arc
suppression.
440
Relay modules
flare
I
2
/10 (A)
Table 2: Overview of protective measures on the switch output
Diode:
Benefit: Can be used for all capacities,
Disadvantage: Very high resetting time
Diode and Zener diode:
Benefit: Low overvoltage (defined by
Disadvantage: Cannot be used for large
capacities
Protective circuit
for load
Diode
Series-connected medium to short
diode / Zener
diode
Suppressor diode medium to short
Varistor
RC
Combination
low overvoltage, compact, cost-
effective
Zener diode), low resetting time
Additional
dropout delay
long
medium to short
medium to short
Defined limit for
induced voltage
yes (UD)
yes (U
yes (U
yes (U
no
ZD
ZD
VDR
)
)
)
Varistor:
Benefit: Low resetting time, cost-
Disadvantage: Cannot be used for all
operating voltages and capacities
RC combination:
Benefit: Low overvoltage, low resetting
time
Disadvantage: High current loading of the
contacts at start-up, more costly and time-
consuming with increased capacity
Bipolar
attenuation
no
no
yes
yes
yes
effective
Benefits /
Disadvantages
Benefits:
Simple implementation
Cost effective
Reliable
Non-critical dimensioning
Small induced voltage
Disadvantages:
Attenuation only via load
resistance
Long dropout delay
Benefit:
Non-critical dimensioning
Disadvantage:
Attenuation only above U
Benefits:
Cost effective
Non-critical dimensioning
Suitable for AC voltage
Limit of positive peaks
Disadvantage:
Attenuation only above U
Benefits:
High absorption of energy
Non-critical dimensioning
Suitable for AC voltage
Disadvantage:
Attenuation only above U
Benefits:
HF attenuation of stored
energy
Suitable for AC voltage
Attenuation is not dependent
on the level
Disadvantages:
Exact values required
High inrush current
Sensitive to harmonic waves
ZD
ZD
VDR