G - AA Electric

Relay coupler – overview
Relay coupler with plugged relay Derating curve Notes on application
Relay coupler
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Relay couplers with plugged relay have
only limited suitability for use in a highly
oscillating environment. Preference should
be given to relay couplers with soldered
relays.
The transition resistance of the relay contacts
is a key factor contributing to temperature
increase inside the relay modules.
This relationship is illustrated by a
derating curve, defined as the function of
the permissible current plotted against the
ambient temperature.
The permissible current (Curve a) is determined
for the following operating conditions:
– Continuous operation
– Rated input voltage + 10 percent
– Several relay modules working under
load, mounted horizontally in rows on
mounting rail, without any spacing
If the modules are mounted with a spacing
> 20 mm, this results in a higher current
load (Curve b). Curve b also shows
the maximum values for switching or
short-time operation in horizontally
mounted state.
The key data of the triggering device must
be precisely adhered to when using UC
versions in DC circuits. As a result of their
pre-circuitry, UC versions take up larger
quantities of current. The internal current
limit of standard initiators can mean that
the triggered relay couplers are not
switched through.
Relay couplers with 24 V AC/DC input are
not suitable for triggering by initiators;
purely DC versions are recommended for
these applications.
RC combination
Long leads are subject to greater electrical
and electromechanical influences. This
may cause malfunctions and even failure
of the relay modules. One possible remedy
is to insert an RC combination to filter
out the interference. RC combinations are
available for all common relay couplers,
as pluggable (PLUGSERIES) solutions or
WDU 12C and DKU 12C terminals.
Sold by AA Electric 1-800-237-8274 Lakeland, FL • Lawrenceville, GA • Greensboro, NC • East Rutherford, NJ www.A-Aelectric.com
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