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| Relays |
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| General Information on Relays |
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There are numerous applications
for relays in Telemetering Technique. They are necessary for the
conversion of pulses
from one form into another (e.g. S0 into bipolar current), for
multiplying individual pulses and distributing them to
multiple receivers (customer / public utility company) or for pulse
value modulation (150 pulses / kWh to 100 pulses /
kWh). Some of our relays offer all three applications combined into one
unit.
Note:
Ordering of HG components only on former explicit request.
Available Housing Types
The first three characters of the relay name provide information on the
type of housing used for that relay. The practical
differences are as follows:
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2NW
4NW
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Smallest housing type, for
top hat rail installation
(according to DIN EN 50022) of the more simple relays such as control
relays.
Dimensions:
2NW 18mm × 90mm × 60mm (W × H × D)
4NW 36mm × 90mm × 60mm (W × H × D)
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7FR
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Special housing for wall
installation, or for installation direct on the
terminal block of the meter.
Dimensions: 110mm × 262mm × 90mm (W × H × D)
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7PA
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Compact housing for wall or
top hat rail installation. 10 connection
terminals provide place for simple conversion, value modulation and
multiplication relays.
Dimensions: 45mm × 76mm × 96mm (W × H × D)
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7PD
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For complex combinations of
relays, providing up to 22 connection
terminals. For wall or top hat rail installation.
Dimensions: 75mm × 73mm × 118mm (W × H × D)
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7PW
RWD
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Compact housing for wall or
top hat rail installation (according to DIN EN 50022) with 16
connection terminals.
Dimensions: 75mm × 76mm × 116mm (W × H × D)
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Modular
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Special housing for top hat
rail installation (according to DIN EN 50022). Types: ITR244, ITR220,
ITR221.
Dimensions: 105mm × 90mm × 60mm (W × H × D)
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KLN
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Special housing for top hat
rail installation (according to DIN EN 50022) with 24 connection
terminals.
Dimensions: 40mm × 79mm × 107mm (W × H × D)
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19"
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Relays for installation in
19"-system mounting racks or in wall
mounted housings.
Types: ITR141 and ITR242
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Survey
of Products Relays as a PDF File
(Filesize[an error occurred while processing this directive] )
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| Inputs / Transmission Distance |
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The S0-interface is
relatively unproblematic and
meant for shorter distances (up to 10m). S0 inputs are active elements.
They supply the pulse detector with a signal, but also with an
auxiliary power supply (our relais use ca. 12VDC). S0 elements can
contain a complete electronic package without the complication of an
extra power supply connection. The S0 specifications comply with DIN
43864 current and voltage limits.
Longer distances (up to 100m)
are better bridged with wipe pulse- (115VAC or 230VAC) or bipolar
current relays for some km (± 24VDC)
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| Auxiliary Power Supply |
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If an auxiliary power
supply is available, then it is best to use relays with wear-resistant
electronic contacts..
Relays that do not use an auxiliary power supply have limited uses
(passive wipe pulses- and outputs or bipolar current
with doubling of the interpreted value) and only allow for low pulse
frequencies (up to about 5Hz).
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The 7PA... relays are
recommended if wall or top hat rail installation is possible. They are
both compact and relatively
inexpensive and usually provide the most practical alternative.
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| Outputs |
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The best results are
provided with wear-resistant
electronic contacts, but they are only available as make contacts at
the present time. Our electronic wipe pulse outputs behave similarly to
relay contacts, meaning that they can carry any kind of current up to a
maximum of 265VAC/DC with 100mA. If double-throw contacts are
required, then the
mercury-wetted reed contacts provide the only alternative.
These contacts are increasingly disapproved of, because of the negative
environmental impact.
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| Galvanic Isolation |
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If the outputs have to be
isolated from each other (e.g. to prevent problems from the customer
side from traveling to the
public utility net), then wipe pulse outputs should be selected. Relays
with bipolar current outputs normally have only
one power supply, meaning that the outputs cannot be isolated from each
other.
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| Pulse Frequency |
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All relay types can be used
up to about 5Hz. For higher frequencies the electronic relays with S0
inputs, and wipe pulse
or bipolar current outputs should be used. Bipolar current inputs
internally produce a 90ms pulse with every pole change
and, because of this, must be specially made with a shortened pulse
length if they are to be used here. Wipe pulse inputs
must be excluded here, because of the long debounce time required when
alternating current is used.
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| Pulse Gear (Pulse Value
Modulator) |
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The values of pulses can be
changed using a pulse value modulator.
Example: A meter delivers 75 pulses per kWh. Each pulse is evaluated as
0.01333 kWh. When a relay with a pulse value
modulator is added, then the resulting pulses can be given values of
e.g. 0.01 kWh, which can be processed by adding
simple tariff units to the system.
Pulse values can be set directly on our tariff units, making pulse
value modulators unnecessary.
At the link
you are find a brief description and some examples for calculation and
adjustment.
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| Pulse Timer |
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Some relays have built-in
"Timers", that make the output pulse length independent of the input
pulse length.
They typically produce 90ms pulses, which is important when the
5Hz-Technic is used. Other pulse values are available
upon request.
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