Laurel Electronics LTE: Ethernet & 4-20 mA Output Transmitter for AC Phase Angle & Power Factor - Manual

LAUREL ELECTRONICS INC. , 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 1
LAUREL
ELECTRONICS, INC.
Ethernet & 4-20 mA Output Transmitter
for AC Phase Angle & Power Factor
Standard Features
• Ethernet Serial Data I/O, Modbus TCP or Laurel ASCII protocol
• 4-20 mA or 0-10V transmitter output, 16 bits, jumper selectable, isolated
• Dual 120 mA solid state relays for alarm or control, isolated
• 5V, 10V or 24V dc transducer excitation output, isolated
• Transmits phase angle between two AC wave shapes of similar period
• Transmits power factor from 1.000 to 0.000 with sinusoidal signals
• For frequencies from 0.005 Hz to 10 kHz, voltages from 10 mV to 250 Vac
• Phase angle resolution of 1°, 0.° or 0.01°, accuracy of 0.01% at AC line frequency
• Analog output resolution 0.0015% of span (16 bits), accuracy ±0.02% of span
• Universal AC power, 85-264 Vac, or low voltage power, 10-48 Vdc or 12-32 Vac
• Power over Ethernet (PoE) jumper selectable with 10-48 Vdc supply
Description
Phase Angle Measurement
Phase angle in degrees indicates the phase lead or lag
between two periodic signals of the same period, as determined
from their zero crossings. These two signals will typically be the
voltage and current applied to a load. As illustrated, the phase
angle in degrees is +360*P1/P.
The Laureate 4-20 mA phase angle transmitter transmits the lead
or lag in degrees from 0° to 360° between two periodic signals of
the same period. In the illustration, phase angle is 360*P1/P. The
signals are applied to the Channel A and B inputs of the Laureate
dual-channel pulse input signal conditioner board. A resolution of
1°, 0.1° or 0.01° is selectable. Accuracy is 0.01% up to 100 Hz,
0.1% at 1 kHz, and 1% at 10 kHz.
Power Factor Measurement
The power factor of an AC power system is the ratio of real
power in watts (W) divided by apparent power in volt-amperes
(VA). For sinusoidal signals, power factor is the cosine of phase
angle.
The Laureate 4-20 mA power factor transmitter computes power
factor as the cosine of phase angle. Power factor readings can
range from 1.000 to 0.000 with three decimal places and an
accuracy of 0.1% for sinusoidal signals at 50/60 Hz power line
frequency. While power factor is always positive, the meter
assigns a minus sign to power factor for negative phase angles,
and it sets power factor to 0 for phase angles greater than 90°.
Phase angle and power factor are determined by timing crystal
clock pulses over a specified gate time which is selectable from
10 ms to 199.99 s. By selecting the minimum gate time of 10 ms,
the update rate can be up to 20/s for 50/60 Hz AC line frequency.
Improved accuracy is obtained by making the gate time long
enough so that multiple cycles can be averaged.
Standard features of Laureate LTE transmitters include:
• Ethernet I/O, isolated. Supported protocols are Modbus
RTU and ASCII (tunneled via Modbus TCP) and Laurel ASCII.
The latter is simpler than the Modbus protocol and is recom-
mended when all devices are Laureates. Note that RS232 or
RS485 data I/O in lieu of Ethernet is provided by our LT Series
transmitters.
• 4-20 mA, 0-20 mA or 0-10V analog transmitter output,
isolated, jumper-selectable and user scalable. All selections
provide 16-bit (0.0015%) resolution of output span and 0.02%
output accuracy of a reading from -99,999 to +99,999 counts
that is also transmitted digitally. Output isolation from signal
and power grounds eliminates potential ground loop problems.
The supply can drive 20 mA into a 500 ohm (or lower) load for
10V compliance, or 10V into a 5K ohm (or higher) load for
2 mA compliance.
• Dual solid state relays, isolated. Available for local alarm
or control. Rated 120 mA at 130 Vac or 180 Vdc.
• Transducer excitation output, isolated. User selectable
5V@100 mA, 10V@120 mA or 24V@50 mA.
• Universal 85-264 Vac power. Low-voltage 10-48 Vdc or
12-32 Vac power is optional.
Discovery and configuration of Laureate Ethernet Nodes is
easily achieved with Laurel's Node Manager Software, and the
discovered transmitters can then be programmed using Laurel's
Instrument Setup Software. Both softwares run on a PC under
MS Windows and can be downloaded at no charge.