Lassen Watthour Meter
Four Wire, Three Phase Wye, 277 Volts to Neutral, 440 or 480 Volts Line to Line
The Lassen meter is used to measure high-voltage, three-phase power that is commonly used in commercial and industrial buildings in North America. This meter can also be used to measure just one or two legs of a three-phase system (a bank of fluorescent lights for example). Just let us know how many CTs you need. Before ordering the Lassen meter, measure the voltage between each leg and neutral to be sure you do not have a high leg (440 or 480 volts to neutral). Order the Shenandoah meter if you do. The Lassen meter consists of an electronics module, three current transformers (CTs) and an electro-mechanical counter that displays the accumulated power used. Enclosures are optional
Available
Configurations
The Lassen meters are available in a variety of configurations. Check the options
in the Part Numbering Guide at the bottom of this page for details.
Current Capabilities
Meters are rated by the maximum current that can flow through the
current transformers. Generally speaking, the meter should be
rated at or above the rating of the breaker that will protect the
circuit to be measured. Meters using solid-core CTs are
available in 20, 100 and 200 amp versions. Meters using
split-core CTs are available in 200, 500, 750, 1000 and 1500 amp
versions.
Resolution
Lassen meters normally come with a resolution of 1.0 kilowatt hours (KWH). They
may also be ordered with a resolution of 0.1 KWH or 0.01 KWH.
Automatic Meter Reading (AMR)
In addition to stand-alone meters that must be manually read, the
meter is available with the following AMR options.
50ms Pulse - An optically isolated output that
closes for 50ms then opens every time the counter advances. These meters are
frequently used with radio data collection systems in apartment buildings.
Dedicated Twisted Pair - A local meter network
that communicates over a twisted pair of wires. Any number of
meters can be connected to an RS-232 interface. The RS-232
interface can be connected directly to a Windows compatible computer,
to a telephone modem, or to a TCP/IP interface module. You can
use the free Microsoft Access application to read the meters or write
your own custom application. See the
documentation section for more info.
Power
Line Carrier - This system is the same as the Dedicated
Twisted Pair except that communication is via the power line instead of
separate wires. Because of interference from nearby ground fault
interrupters and switching power supplies, this system works best in
marinas.
Enclosures
The Lassen meter is available in a variety of enclosures, either for
a single meter or multiple meters. See the enclosures page for
more info.
OEM Versions
The Lassen meter is also available in an OEM version so that it can
be installed in a third party NEMA enclosure. This is usefull
when the meters are to be installed in power pedestals in a marina or
RV park. A stainless steel mounting plate is available for
mounting the display counters in the enclosure.
Alternate Configurations
The Lassen can also be used with just one or two CTs if desired.
If the meter is not to be mounted
in a permanent location, buying a three element meter now gives you the flexibility to use
it anywhere in the future.
Accuracy and Safety Certifications
Davidge Controls certifies that all our watthour meters meet or exceed
the accuracy standards of ANSI C12.1(2001), the national standard for
watthour meters that applies to all the utility companies in the
country.
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