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Power Solid-State Relays from Weidmüller: New non-wearing one- and
three-phase PSSR modules reliably switch AC loads up to 20 A in
industrial environments and high temperatures.
Weidmüller’s new Power Solid-State Relays (PSSR) are available as
single- and three-phase versions. In comparison with contactors and
standard relays PSSRs switch without any wear and are totally silent. The
modules have a high peak load rating and as such have sufficient
reserves to trip line-side fuses. They can easily cope with capacitive and
inductive current spikes.
With integrated zero-voltage switching, single-phase PSSRs are eminently
suitable for switching resistive loads up to 20 A in 55 °C heat. Example
applications: pulsing cartridge heaters in injection molding machines
manufacturing plastic components or switching infrared emitters in
hardening plants or sewage works. These modules are distinguished by a
low zero-voltage switching range. Three-phase PSSRs are designed with
instantaneous switching functionality and are suitable for use in motor
controls deployed in mechanical and systems engineering applications.
Both PSSR 1PH and PSSR 3PH versions are ‘ready-to-use’; that means
users simply snap them onto the mounting rail and connect them. In other
words, the modules do have to be laboriously mounted onto a mounting
plate or the wall of an electrical cabinet.
Power Solid-State Relays offer several advantages in comparison with
electromagnet relays. They operate extremely reliably over a long service
lifespan, they are compact, have low drive power requirements and extremely
fast response times. PSSRs switch loads silently and bounce-free. They are
insensitive to shock impact and vibration. And, in addition, they do not subject
adjacent component groups to electromagnet emissions or switching sparks
during switching operations. During the switching operation, the optocoupler is
triggered by the control circuit. That in turn ensures the electrical isolation to
the load circuit. The optocoupler output activates a power semiconductor,
TRIAC or anti-parallel connected thyristors in the load circuit. An integrated
suppressor circuit comprising varistors and RC combinations protect the load
Weidmuller Ltd, 1 Abbey Wood Road, Kings Hill, West Malling, Kent, ME19 4YT
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Technical: 0845 094 2007
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circuit against overvoltage surges. Power Solid-State Relays are predestined
to switch higher load currents. Weidmüller’s PSSR modules have a high peak
load rating and as such have sufficient reserves to trip line-side fuses. They
are capable of withstanding capacitive and inductive interference. Technical
data: PSSR 1PH -> I²t = 312 A²s, 10 ms; PSSR 3PH -> I²t = 1500 A²s, 10 ms.
In many industrial applications the switching capacity of electromagnet
contactors is insufficient to switch loads reliably over longer periods of time.
Single-phase Power Solid-State Relays are deployed, for example, to pulse
cartridge heaters in injection molding machines to regulate the heating power.
In comparison with electromechanical elements Weidmüller’s PSSRs do not
wear out, which means they have an unrestricted operating lifespan. The
example ‘pulsing a cartridge heater in an injection molding machine’ illustrates
the point; switching 60 times a minute whilst operating 12 hours a day for 250
days a year results in 10 800 000 switching operations per annum. A
conventional standard contactor states a mechanical lifespan of 30 million
switching operations, which corresponds to a mere three years. Moreover, the
switching noise made by contactors in systems engineering applications or in
processes close to where people work is often found to affect their
concentration or is considered downright annoying. In such cases, Power Solid
State Relays are a first-class choice as they are absolutely silent when
switching. Three-phase PSSRs are utilised to control motor loads, heating
systems and transformers. And the same applies here, their silent and non
wearing switching functionality are compelling advantages of these Power
Solid-State Relays.
Both PSSR 1PH and PSSR 3PH versions are ‘ready-to-use’; that means users
simply have to snap them onto the mounting rail and connect them. The
Power Solid-State Relays offered by other manufacturers do not have this
simple ‘handling’ capability. Their modules are frequently installed on the outer
walls or doors of the electrical cabinets to allow the heat to dissipate better –
which is costly in terms of both time and materials. In addition, this form of
installation requires the use of a thermal compound – so the amount of soiling
this causes is correspondingly high. Weidmüller’s Power Solid-State Relays do
Weidmuller Ltd, 1 Abbey Wood Road, Kings Hill, West Malling, Kent, ME19 4YT
Sales: 0845 094 2006
Technical: 0845 094 2007
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not need any thermal compound whatsoever. This solution means that
residues, contamination and soiling have been confined to history.
Weidmüller has two types of single-phase PSSRs on offer: PSSR 24VDC/1PH
AC 20A and PSSR 230VAC/1PH AC 20A. And there are two variants of the
three-phase PSSRs available: PSSR 24VDC/3PH AC 15A and PSSR
230VAC/3PH AC 15A. Each module is fitted with a green LED to indicate the
operating state. Single-phase modules can operate in ambient temperatures
between -30 and +80 °C, and the three-phase modules can operate in
temperatures ranging between -40 and +80 °C without restriction. With
Weidmüller’s PSSRs the nominal switching current in the load circuit has been
rated with industrial applications in mind; the nominal switching current is
based on an ambient temperature value of 55 °C. Weidmüller’s PSSR carry
the CE mark; cURus approval is being prepared. All modules are suitable for
extensive marking with equipment markers.
The new Power Solid-State Relays are a part of our progressive and extensive
palette of products designed to meet customer requirements in the field of
functional electronics. This includes analogue signal conditioning modules,
relays and optocouplers, power supplies, overvoltage protection solutions,
PLC interfaces and fieldbus products. The components are designed to be
utilised in industrial, process automation and power generation applications
requiring protection class ratings IP 20 and IP 67.
Key word: Power Solid-State Relays from Weidmüller
For more information: www.weidmueller.com
Weidmuller Ltd, 1 Abbey Wood Road, Kings Hill, West Malling, Kent, ME19 4YT
Sales: 0845 094 2006
Technical: 0845 094 2007
Visit our website and see what`s new! Our address is www.weidmuller.co.uk
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Captions:
Fig. 1: Power Solid-State Relays from Weidmüller: New single- and threephase PSSR modules designed for reliable long-term load switching.
Fig. No.: Sä 280210D
Fig. 2: Power Solid-State Relays from Weidmüller: Single-phase Power
Solid-State Relays are used to pulse cartridge heaters in injection
molding machines.
Fig. No.: Sä 280211D
Weidmuller Ltd, 1 Abbey Wood Road, Kings Hill, West Malling, Kent, ME19 4YT
Sales: 0845 094 2006
Technical: 0845 094 2007
Visit our website and see what`s new! Our address is www.weidmuller.co.uk