Laurel Electronics for Digital Panel Meters, Counters, Timers, Transmitters, Digital Displays

Digital Panel Meters - Counters - Timers - DIN Rail Transmitters - Large Digit Displays

   

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Laureate™ True AC RMS Voltage
& Current Digital Panel Meter

0.2 V - 600 V and 2 mA - 5 A full-scale ranges

CE Mark   UL Mark RoHS Mark Made in California

Standard Features

Product Info

Specs
Mechanical
Serial I/O options
Power options
Relay options
Analog output option
Meter manual
Serial manual
Modbus manual
Setup software
Pricing
  • 0.2, 2, 20, 200 & 600 V ranges
  • 2, 20, 200 mA & 5 A ranges
  • 4-1/2 digit resolution
  • 99.9% accuracy of full scale
  • AC coupled input
  • Crest factor of 2.4 at full scale
  • Priced competitively with less capable averaging AC meters
  • Scalable for external current shunts or current transformers
  • Peak or valley display
  • 85-264 Vac universal AC power
  • Green or red display
  • NEMA 4X, 1/8 DIN case
  • Certified to UL 61010C-1 (UL mark), EN 61010-1 (CE mark), and RoHS).
    Options:
  • Low voltage power: 10-48 Vdc or 12-30 Vac
  • Dual relays: Form C contact or Form A solid state
  • Analog output: Isolated, 4-20 mA, 0-20 mA, 0-10V, -10 to +10V
  • Serial communications: RS232, RS485, Modbus RS485, USB, USB-to-RS485 converter

Description

The Laureate™ True RMS meter offers a high-accuracy 4-1/2 digit display for five voltage ranges and four current ranges. It is suited for AC applications where there is considerable distortion of current waveforms from nonlinear loading. The input is AC coupled to read only the AC component, such as ripple on a power supply.

Signal conditioner board for Laurel True AC RMS Voltage & Current digital panel meterThe True RMS meter uses precision circuitry to compute the root-mean-square of complex waveforms from 10 Hz to 10 kHz. Spikes up to 2.4 times the maximum of each range are accurately measured. This provides a crest factor (Vp / Vrms) of 240 for a signal amplitude of 1% of full scale, decreasing to 2.4 at 100% of full scale.

Use with Current Transformers

High common mode rejection allows stable readings with current shunts located on the high side of the line. Five amp input capability allows the output of 5 A current transformers to be applied directly to the meter, with no need for a stepdown transformer. The current reading can easily be scaled to display the input to the current transformer. Digital scaling and calibration eliminate zero and span drift associated with potentiometers in non-microcomputer based meters.

High Accuracy

Frequency and amplitude operating range of Laurel True AC RMS Digital Voltmeters and Ammeters

Maximum error as a function of frequency
and signal amplitude

The typical accuracy is 99.9% of full scale, decreasing to 99.8% for low frequency at high amplitude, or high frequency at low amplitude. The above graph shows that maximum error is 0.1% of full scale over all frequency ranges of interest to AC power measurement. Error increases to 0.2%, represented by the two shaded areas, at low frequency and high amplitude, or high frequency and low amplitude.

Crest factor increases in inverse proportion to signal amplitude. As shown on the same graph, the maximum crest factor (Vp / Vrms) is 2.4x at full-scale amplitude, increasing to 240 at 1% of full-scale amplitude.

The Laureate RMS meter utilizes the same high-speed analog-to-digital conversion method as all other Laureate panel meters. However, the meter settling time and control response to a step change in AC amplitude are limited by the RMS converter circuit to approximately 1 second.

Interface Options

Plug-in isolated analog output, dual relay, and serial communications options can upgrade the Laureate from a simple monitor to system interface and control.

Built-in Flexibility & Safety

Laureates may be powered from 85-264 Vac or optionally from 12-30 Vac or 10-48 Vdc. They are available with red or green LEDs. They are housed in a 1/8 DIN case that meets NEMA 4X (IP65) specifications from the front when panel mounted. Any setup functions and front panel keys may be locked out for simplified usage and security.

Specifications

AC Voltage (1% to 100% of full scale)

AC Voltage Range Resolution Input
Ohms
Typ Error at 25°C
10 Hz to 10 kHz
200.00 mV
2.000 V
20.000 V
200.00 V
  600.0 V *
300.0 V
10 µV
100 µV
1 mV
10 mV
100 mV
100 mV
22 M
22 M
1 M
1 M
1 M
1 M
0.15% FS
0.15% FS
0.15% FS
0.15% FS
0.15% FS
0.15% FS
 
          * Range does not include U/L certification.

AC Current (1% to 100% of full scale)

AC Current Range Resolution Input
Ohms
Typ Error at 25°C
10 Hz to 10 kHz
2.0000 mA
20.000 mA
200.00 mA
5.000 A
0.1 µA
1.0 µA
10 µA
1.0 mA
100
10
1
0.01
0.15% FS
0.15% FS
0.15% FS
0.25% FS

Both AC Voltage & Current

Display
Readout
Range
Indicators
5 LED digits, 7-segment, 14.2 mm (.56"), red or green
-99999 to 99999 or -99990 to 99990 (count by 10)
2 red LED lamps
Accuracy
Span Tempco
Zero Tempco
Crest Factor
0.005% of reading/°C
0.1 count/°C
2.4x at 100% of full scale
Response Time
RMS to DC
A-to-D rate
Output Update
Display Update
1 s conversion settling time
60/s at 60 Hz, 50/s at 50 Hz
56/s at 60 Hz, 47/s at 50 Hz
3.5/s at 60 Hz, 3/s at 50 Hz
Maximum Signal
Max applied voltage
Current protection
600 Vac for 20, 200, 600V ranges, 125 Vac other ranges
25x for 2 mA, 8x for 20 mA, 2.5x for 200 mA, 1x for 5 A
Power
Voltage, standard
Voltage, optional
Frequency
Power Isolation
85-264 Vac or 90-300 Vdc (DC operation not UL approved)
12-30 Vac or 10-48 Vdc
DC or 47-63 Hz
250V rms working, 2.3 kV rms per 1 min test
Excitation Output (standard)
5 Vdc
10 Vdc
24 Vdc
Output isolation
5 Vdc ±5%, 100 mA
10 Vdc ±5%, 120 mA
24 Vdc ±5%, 50 mA
50 Vdc to meter ground
Analog Output (optional)
Output levels
Current compliance
Voltage compliance
Scaling
Resolution
Isolation
4-20 mA, 0-20 mA, 0-10V, -10 to +10V (jumper selectable)
2 mA at 10V ( > 5 kOhm load)
12V at 20 mA ( < 600 Ohm load)
Zero and full scale adjustable from -99999 to +99999
16 bits (0.0015% of full scale)
250V rms working, 2.3 kV rms per 1 min test
Dual Contact Relay Outputs (optional)
Relay Type
Load Rating
Isolation
Form C
8A at 250 Vac or 24 Vdc
250V rms working, 2.3 kV rms per 1 min test
Dual Solid State Relay Outputs (optional)
Relay Type
Load Rating
Isolation
Form A, SPST, normally open
130 mA at 140 Vac or 180 Vdc
250V rms working, 2.3 kV rms per 1 min test
Serial Data I/O (optional)
Board Selections
Protocols
Data Rates
Digital Addresses
Isolation
RS232, RS485, Modbus RS485, USB, USB-to-RS485 converter
Modbus RTU, Modbus ASCII, simpler Laurel ASCII
300 to 19200 bps
247 (Modbus), 31 (Laurel ASCII),
250V rms working, 2.3 kV rms per 1 min test
Signal Connections
Environmental
Operating Temperature
Storage Temperature
Relative Humidity
Protection
0°C to 60°C
-40°C to 85°C
95% at 40°C, non-condensing
NEMA-4X (IP-65) when panel mounted

AC line monitoring using a LaurelAC RMS Voltmeter, AC RMS Ammeter, and AC Line Frequency Meter

Using Laureate Meters and Counters to Instrument an AC Line

 
Why Measure AC Power?

Many AC loads, such as electrical motors, will only operate reliably if the AC line voltage and frequency are within specified tolerances. Otherwise permanent damage to expensive plant equipment may occur. Motor generators and UPS systems will only operate reliably with the load for which they are rated. Drops in line voltage or frequency may indicate an excessive load and the possibility of equipment damage.

Laureate meters and counters are low-cost means to instrument AC power lines with great accuracy:
  • AC RMS Voltmeter. Full-scale ranges of interest are 200.00 V with 10 mV resolution and 600.0 V with 100 mV resolution. True RMS capability allows the display of RMS voltage for non-sinusoidal waveshapes, such as square waves from a UPS.
     
  • AC RMS Ammeter. A built-in 5 A range can be used to display currents up to 5.000 A with 10 mA resolution, or to accept the output of 5 A current transformers. The 200.00 mV range can be used with external current shunts. With either transformers or shunts, scaling to the input current is easily accomplished via the meter's front panel pushbutton switches.
     
  • Frequency Meter. Inverse period is used to determine AC line frequency to six-figure accuracy (60.0000 or 50.0000) in a few line cycles plus 30 ms.
      
  • Phase Angle Meter. Two signals with identical periods are applied to Channels A and B of the Laureate phase angle meter. A display from -180º to +180º is obtained by timing the rising edge of one channel and the falling edge of the other channel. A resolution of 1º, 0.1º or 0.01º is selectable. Accuracy is .01% up to 100 Hz, .1% at 1 kHz, and 1% at 10 kHz.

Using Laurel Meters to Synchronize Two Motor Generators

Using Laureate Meters to Synchronize Two Motor Generators

Successful synchronization of two motor generators requires that the voltage outputs of the generators be close to each other, that the two frequencies be identical, and that the voltage waveshapes be in phase.
  • The two voltages can be measured by two Laureate AC RMS Voltmeters, which offer 200.00 V and 600.0 V ranges. Or a single meter can be multiplexed by using an external toggle switch.
     
  • The two frequencies can be measured to six-figure accuracy by a single Laureate Dual Channel Counter, where each channel monitors a generator. The two AC neutrals must be tied to meter ground. Pressing a front-panel key toggles the reading between the channels.
     
  • Phase angle can be measured using the Laureate Phase Meter.

Ordering Guide
Laureate™ True AC RMS Voltage & Current Panel Meters
 Click on the radio buttons to build a model number with pricing (shown below the Ordering Guide).

Quantity

DPM
Type
L    Laureate Digital Panel Meter $220
Main
Board
Standard Main Board, Green LEDs
Standard Main Board, Red LEDs
NC
NC
Power Isolated 85-264 Vac
Isolated 12-30 Vac or 10-48 Vdc
NC
$30
Relay
Output
None
Dual 8A Contact Relays
Isolated Dual Solid State Relays
NC
$80

$55
Analog
Output
None
Isolated 0-20 mA & 0-10 V
NC
$90
Digital
Interface
None
Isolated RS232
Isolated RS485
Isolated Modbus RS485
USB
USB-to-RS485 converter
NC
$60

$80

$90
$60
$100 
Signal
Input
True AC RMS Amps
RMV1  200.00 mV
RMV2  2.0000 V
RMV3  20.000 V
RMV4  200.00 V
RMV5  600.0 V (range does not include U/L certification)
RMV6  250.0 V
 
$35
True AC RMS Amps
RMA1  2.0000 mA
RMA2  20.000 mA
RMA3  200.00 mA
RMA4  5.000 A
 
$35
Note: The same AC RMS signal conditioner can be user configured for AC Volts or AC Amps. It is precalibrated in EEPROM for all AC Volt and AC Amp ranges listed.
Add-on
Options
EB  Extra-bright Red LED Display
BL  Blank Lens without Button Pads
CBL01  RJ11-to-DB9 Cable
CBL02  USB-to-DB9 Adapter
CBL05  USB Cable, A to B
IPC  Splash-proof Cover

BOX1  NEMA-4 Enclosure
BOX2  NEMA-4 Enclosure plus IPC
$30
NC

$19
$39
$15
$40
$140
$180
 
Configured model number L20000RMV1
Configured price per model $255
Quantity 1
Extended price $255


 

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laurels Logo Laurel Electronics, Inc.
Industrial Instrumentation & Displays
3183-G Airway Avenue
Costa Mesa, CA 92626, USA
Tel:      
Fax:
     
(714) 434-6131
(714) 434-3766

  
© 1996-2009 Laurel Electronics, Inc.