PR300 Power and Energy Meter

This panel-mounted power and energy meter with a large, three-row LED display integrates all the measuring functions required for power management in locations such as factories and buildings into a single unit.

With the objective of working toward the preservation of the global environment by saving energy and performing equipment maintenance, the PR300 is designed to display and output the energy of various types of electrical equipment.

Large Triple Display and Multimeter Function

Combine three desired measurement items and show them all at once on the large LED display. Just one PR300 unit can take the place of two or more meters, dramatically contributing to savings in cost, space and wiring.

PR300 comes with measurement functions for reactive power, apparent power, demand current, demand power, and other items, as well as with a transducer function.

SET/ENT The user can optionally select an item to be displayed for each line of the display. Even during measurement, the display parameter can be changed with one touch using the SET/ENT key.

Examples of Display Item Combinatons

* Use SEL key to view phase Amps and Volts.

Wide Choice of Measurement Items

*denotes optional.

Universal Design

PR300 versatilely supports a wide range of phases and wire systems, from a single-phase two-wire system to a three-phase four-wire system. The phase and/or wire system, including CT/VT ratios, can be selected or changed on site using the panel keys. For panel mounting, PR300 supports various standards with different shapes and sizes.

These make your power monitoring even more efficient!

Other RS-485 devices can be connected to the network using Ethernet–serial gateway function.

PR300 comes complete with functions necessary for efficient power monitoring, including power integration over a desired period, a transducer function (4 to 20 mA DC output), an integrated pulse output of electric energy, demand current/power alarm output functions, RS-485 communication (Modbus/PC link), and Ethernet communication.

Optional integrating function

Power is integrated while a control signal for optional integration is on. When the control signal is switched from off to on, the optional integrated value indication is reset and integration starts. (The integrated value prior to the reset is held in a register.) The integrated value cannot be guaranteed in the event of a power failure occurring during integration.

Demand measurement (when demand measurement is specified)

The PR300 measures average power or average current within a set demand period. The maximum demand value for the demand measuring time is held until the power is turned off, remote reset is executed, or the next demand measurement is started.

Display and Operation Specifications

(1)	Measured Value Display	5-digit, 3-row, 7-segment LED display Display color: red
		Measured Value display	Measurement Item Display Active energy [kWh, MWh] *1 Reactive energy ±[kvarh, Mvarh] *2 Apparent energy [kVAh, MVAh] *1 Regenerative energy -[kWh, MWh] *2 Optional active energy [Wh] Active/regenerative power (instantaneous, maximum, and minimum values) [W, kW, MW] *2, *3 Reactive power (instantaneous, maximum, and minimum values) [var, kvar, Mvar] *2, *3 Apparent power (instantaneous, maximum, and minimum values) [VA, kVA, MVA] *1, *3 Voltage (instantaneous, maximum, and minimum values) [V, kV] *1, *3 Current (instantaneous and maximum values) [A, kA] *2, *4 Power factor (instantaneous, maximum, and minimum values) LEAD: d[COSφ] LAG: G[COSφ] *3 Frequency (instantaneous, maximum, and minimum values) [Hz] *3 Demand power Maximum demand power [W, kW, MW] [DEMAND] *4 Demand current Maximum demand current [A, kA] [DEMAND] *4 *1: Without sign, but with a decimal point *2: With a sign and a decimal point ("+" is not indicated). Regenerative power (energy) always shows " − " negative indication. The position of a decimal point differs depending on the primary rated power, VT ratio, and CT ratio. *3: "MAX" lights up for the maximum value and "MIN" lights up for the minimum value. *4: "MAX" lights up for the maximum value.
		Measured Value screen	Display pattern	The measurement items you want to display are assigned to each of the upper, middle, and lower displays to provide indications using three display rows as one pattern. Up to eight display patterns can be set. The initial values are as shown in the following table. (Combinations other than those shown in the following table are also available if the parameters are set.)
			Number of display patterns	Can be set in the range of 1 to 8. Pressing the SET/ENT key switches the display from "display pattern-1," "display pattern-2," and so on in order according to the number of patterns set. The initial value is "1" and only display pattern-1 is displayed when this value is set.
			Display Pattern-1 Display Pattern-2 Display Pattern-3 Display Pattern-4 Display Pattern-5 Display Pattern-6 Display Pattern-7 Display Pattern-8 Upper display Current (Phase switch indication)* Active power Active energy Current-1 Voltage-1 Current (Phase switch indication)* Current (Phase switch indication)* Active power Middle display Voltage (Phase switch indication)* Reactive power LEAD reactive energy Current-2 Voltage-2 Voltage (Phase switch indication)* Active power Maximum demand value Lower display Active power Power factor Apparent energy Current-3 Voltage-3 Frequency Power factor Demand value * The display of current (phase switch indication) is switched between current-1, current-2, and current-3 each time the SEL key is pressed. The display of voltage (phase switch indication) is switched between voltage-1, voltage-2, and voltage-3 each time the SEL key is pressed.
		VT ratio/CT ratio	If the VT ratio and CT ratio are set, input to the PR300 is displayed after converting it to the primary input value before VT or CT. The VT and CT ratios can be set via communication or using the operation keys. VT ratio setting range: 1 to 6000* CT ratio setting range: 0.05 to 32000* * Set the VT ratio and CT ratio so that [secondary rated power] x [VT ratio] x [CT ratio] is smaller than 10 GW.
(2)	Unit Lamps	The relevant unit lamp lights up according to a measurement item and measured value. Display color: red
(3)	MAX and MIN Lamps	Either the MAX or MIN lamp lights up when a maximum or minimum measured value is displayed. Display color: red
(4)	Phase Indication Lamps	Indicate the phase to which the measured value corresponds. (The A, B, and C indications or R, S, and T indications should be specified in accordance with the suffix code.) Display color: red
		Phase and Wire System Voltage-1 Voltage-2 Voltage-3 Current-1 Current-2 Current-3 Single-phase two-wire system A (R) - - A (R) - - Single-phase three-wire system A, B (R, S) B, C (S, T) - A (R) C (T) - Three-phase three-wire system A, B (R, S) - B, C (S, T) A (R) - C (T) Three-phase four-wire system A (R) B (S) C (T) A (R) B (S) C (T) Three-phase four-wire system (2.5 element) A (R) - C (T) A (R)* - C (T)* * Can be measured only when the current is in a state of equilibrium. Blinks (4 times/sec) until it returns to normal when the communication error occurs. Display color: green
(5)	Power Lamp	Lights up when power is supplied.
(6)	Commu-nication Lamp	Blinks during communication (RS-485 or Ethernet). Display color: green
(7)	Pulse Output Lamp	Lights up when output is produced during pulse output, and goes out when no output is produced. Display color: green
(8)	Demand Alarm Lamp	If a demand value exceeds the demand alarm point at a time other than during the alarm mask time, the OVER lamp lights up to indicate the occurrence of an alarm. Display color: red
(9)	Phase and Wire System Lamps	The lamps of the phase and wire system that have been set light up. Display color: green
(10)	Input Range Lamps	The input voltage range (150 V, 300 V, or 600 V) and input current range (1 A or 5 A) that have been set light up. Display color: green
(11)	DEMAND Lamp	Lights up when a demand value is displayed. Display color: red
(12)	Operation Keys		Used to switch measured value display patterns. This key is also used for setting parameters.
			Used to move the display digit during energy indication. This key is also used for setting parameters.
			Used to display the maximum or minimum measured value. These keys are also used for setting parameters.
			Used to switch phase indications when the PR300 displays a voltage or current for which phase indication can be changed. (Phase switch indication is not available for single-phase two-wire system.) This key is also used for setting parameters.
			Used to start/stop demand measurement. The lamp in the key lights up during demand measurement. Display color: green
Indicator-out Mode Setting		This function turns off LEDs after a certain time elapses, with the exception of the power lamp (LED). The ON/OFF setting of the indicator-out mode function and the wait time before entering the indicator-out mode can be set using the operation keys. (Cannot be set via communication.) Indicator-out mode: ON/OFF (initial value: OFF) Indicator-out mode wait time: 1 to 60 minutes (resolution: 1 minute) (initial value: 10 minutes)
A/D Sampling Rate, Data Update Interval		A/D sampling rate: 4.8 kHz Internal measurement data: display/communication data is updated at an interval of 1 second or less

Communication Specifications

RS-485 communication

Example

Example of Connection Diagram

Notes:
The PR300 employs a two-wire system for RS-485 communication.
 SG: The SG terminal is connected to match the signal level of the RS-485 communication line.
 FG: All shielded wires must be connected and then grounded at one place to provide noise protection for RS-485 communication lines.

Ethernet communication (when the Ethernet communication function is specified)

Example:

Function	Ethernet communication enables you to use the command/response method to read a variety of measurements and write various settings. The PR300 can be connected to IEEE802.3-compliant networks (10BASE-T/100BASE-TX).		Higher-level device (PC etc.)
		Application layer	MODBUS/TCP
		Transport layer	TCP, UDP
		Network layer	IP, ICMP, ARP
		Data link layer	Ethernet
		Physical layer	10BASE-T/100BASE-TX
Communication Specifications	Protocol	Modbus/TCP
	Access Control	CSMA/CD
	Baud Rate	10 Mbps/100 Mbps
	Maximum Segment Length	100 m (distance between the hub and module)
	Maximum Connecting Configuration	Maximum of 4 levels of cascading (for 10BASE-T) or maximum of 2 levels of cascading (for 100BASE-TX (Number of hubs that can be cascade connected)
IP Address	IP addresses can be set using the operation keys on the front of the PR300.
Modbus/TCP Function	Code	Function	Description
	03	Reads data from multiple D registers	Capable of reading data from up to 64 registers continuously.
	06	Writes data into D register	Capable of writing data into one register.
	08	Performs loopback test	Capable of performing a communication test.
	16	Writes data into multiple D registers	Capable of writing data into up to 32 registers continuously.
Overview of Modbus/TCP Protocol	The structure of Modbus/TCP protocol is as follows:
			The Simple Protocol Data Unit (PDU) is the same as Modbus/RTU (Modbus protocol via serial communication).
	The Modbus Application Protocol Header(MBAP Header) is made of the following seven bytes:
	Byte No 0 1 2 3 4 5 6 Description Transaction ID Protocol ID Number of bytes Unit ID
	Transaction ID: Set any value for identifying the transaction. The PR300 returns a value received from a higher-level device as a response. Protocol ID: Specify "0" for the Modbus/TCP protocol. Number of bytes: Number of bytes after the unit ID (byte number 6) Unit ID: The PR300 returns a value received from a higher-level device as a response.
Ethernet- Serial Gateway Function	The PR300 has an RS-485 communication terminal in addition to an Ethernet communication connector. Modbus/TCP commands received by Ethernet are relayed to the RS-485 terminal. This enables the PR300 to connect to a device with an RS-485 communication function (Modbus/RTU protocol) via a network.
	RS-485 communication Protocol Modbus/RTU Baud Rate 9600 bps Parity Even, odd, or none Stop Bit 1 bit Data Length 8 bits

Connection Diagrams

A phase and wire system can be selected by specifying the parameters. If measurement input does not exceed 600 V AC or 5A AC, direct input without using a VT or CT is possible. Do not ground the input circuit when a VT or CT is not used. Perform wiring for the voltage and current in the same circuit.

Single-phase two-wire system

Single-phase three-wire system

Three-phase three-wire system

Three-phase four-wire system

Three-phase four-wire system (2.5 element)

External Dimensions

ANSI 4-inch round form size (when a bezel is attached)

panel cutout dimensions

Normal Allowable Deviation= ± (Value of JIS B 0401-1999 tolerance grade IT18)/2

DIN 96-square instrument size

panel cutout dimensions

Normal Allowable Deviation= ± (Value of JIS B 0401-1999 tolerance grade IT18)/2