ROOTECH - Energy Solution for Human and Nature

Digital Power Meter

Display
Shows real–time measurement data on the FND display screen
Voltage
Line–to–neutral voltage, Line–to–line voltage, Fundamental frequency, Harmonics, Phasor diagram, THD¹
Symmetrical components(positive–, negative–, zero–sequence),Voltage unbalance based on symmetrical components, voltage unbalance according to the NEMA standard, Residual voltage
Current
Phase current, Fundamental frequency, Harmonics, Phasor diagram, THD¹, TDD²
Symmetrical components(positive–, negative–, zero–sequence), Current unbalance based on symmetrical components, Current unbalance according to the NEMA standard, Residual current
Power
Active, Reactive, and Apparent power
Power Quality
Voltage / Current harmonics	Magnitude of each harmonic up to the 50th order, THD, Current TDD, Crest factor, K–factor
Unbalance(voltage/current)	Unbalance according to the NEMA standard, Negative–/zero–sequence unbalance based on symmetrical components
Phasor	Voltage and current phasor
Waveform	Voltage and current waveforms
	12 cycles of waveforms(128 samples/cycle)
Events
Detection of fuse fail, phase open, blackout, and over-temperature events
Max. number of event logs	50
Saved event data	Saves event data, including timestamps in nonvolatile memory
Aggregation of Measurement Data
Aggregation intervals	7 fixed intervals		1 and 5 seconds, 1 and 5 minutes, 1 and 6 hours, and 1 day
Aggregation for average value	Average value		Average value of the values measured for 0.2 seconds
	Max/Min value		Max/Min value of the values measured for 0.2 seconds
Aggregation for the latched value¹	Last latched value		Provides the last measured data by latching the value
Data displayed on the FND screen	Average value		Average values of the values measured for 0.2 seconds in the 1-second aggregation interval
	Max/Min value		Max/Min values of the displayed average values aggregated at 1-second intervals after resetting the values
Connections of IO Modules
Users can check the measurement data and connection status of the connected IO modules with the function to automatically detect module connection status and set up module IDs.
Max. number of IO modules connectable to the back of the meter		2
External Communication with the Host System
Ethernet communication⁴	Communicates with the host system using the Modbus TCP protocol at 100 mbps
	Transfers a large amount of measurement data to the host system at high speeds
	Two ports allow for Ethernet connection between Accura 3550 devices.
	Wiring: Star, Daisy–chain, Ring connections (RSTP⁵ support)
RS-485 communication	Communicates with the host system using the Modbus RTU protocol
	1,200 / 2,400 / 4,800 / 9,600 / 19,200 / 38,400 / 57,600 / 115,200⁶ bps
Power Supply
Installation category	CAT Ⅱ
Power Consumption
Power supply voltage⁷	AC 100 ― 240 V 50/60 Hz, DC 100 ― 300 V		Power supply option:AC/DC 110 - 220 V
	DC 48 V		Power supply option: DC 48 V
Power consumption	Max. 4 W when there are no IO modules connected
	Max. 12 W when there are 2 IO modules connected

1. THD(Total Harmonic Distortion). Voltage THD:

, Current THD:

:fundamental voltage,

:fundamental current
2. TDD(Total Demand Distortion). Current TDD:

:peak demand current
3. For specific measurement parameters including energy, demand, and IO modules’ digital input and output data,
the device provides the data measured for the last 0.2 seconds by latching the data.
4. The built-in switch allows for Ethernet connection between Accura 3550 devices without a separate external switch.
5. RSTP(Rapid Spanning Tree Protocol), IEEE 802.1D–2004
6. At 115,200 bps, a master can communicate with up to 16 slave devices, and the maximum distance between the master and
the slave is 600 m.
7. The device conforms to UL standards for the tested AC power supply voltage.

IO Modules

Accura 3550 comes with various IO modules that can be easily connected to the back of the device. Up to four modules can be attached regardless of connection sequence, and the same types of modules can be redundantly connected.
Model	Number of Channels		Specifications	Power Consumption
DC module	DC voltage input	1	0 – 200V	2.0 W
	DC current input	2	–100 – 100 mV(shunt resistance required)
	Digital input	4	Internal DC 24 V power supply(Self excitation), redundant circuits
	Digital output ¹	1	Dry contact(external excitation)
DIO module	Digital input	8	Internal DC 24 V power supply(Self excitation), redundant circuits	2.2 W
DIO module	Digital output ¹	2	Dry contact (external excitation)	2.2 W
Accura 3550 DI module	Digital input	12	Internal DC 24 V power supply(Self excitation), redundant circuits	3.2 W
DO module	Digital output ¹	6	Dry contact (external excitation)	0.4 W
AI module	Analog input	6	DC 0 – 20 mA	0.6 W
AO module	Analog output²	6	DC 0 – 20 mA	3.6 W
A4D2 module	Analog output²	4	DC 0 – 20 mA	2.6 W
A4D2 module	Digital output ¹	2	Dry contact(external excitation)	2.6 W
A2D4 module	Analog output²	4	DC 0 – 20 mA	1.7 W
A2D4 module	Digital output ¹	4	Dry contact(external excitation)	1.7 W
RTD module	RTD input	3	PT100, PT1000 4–wire, 3–wire, 2–wire module	0.8 W
ELD module	Leakage current input	6	AC 0 – 2,000mA	0.7 W
ELD module	Digital output ¹	1	Dry contact(external excitation)	0.7 W
TEMP module	Collects temperature and humidity data(Up to 6 Accura TSEN/THSEN³ devices can be connected to the TEMP module with communication ports.)			0.9 W⁴
Accura TSEN	Measures temperature with the IC temperature sensor			0.12 W
Accura THSEN	Measures temperature and humidity with the IC temperature and humidity sensor			0.12 W
Operation
Digital/Analog input detection cycle	1 msec
Digital output (energy pulse) control cycle	1 sec
Analog output (measurement) control cycle	200 msec
Analog output (communication) control cycle	20 msec
Power Supply
Receives power from Accura 3550

1. DO channels support latches, pulses, and energy pulses.
2. The values measured by Accura 3550 or the command values provided via communication are converted into values between 0 and 20 mA or 4 and 20 mA to output analog signals.
3. The communication cables used to connect the TEMP module to Accura TSEN/THSEN devices are not provided.
4. It indicates the power consumption when 6 Accura TSEN/THSEN devices are connected to the TEMP module.

Digital Power Meter

Voltage Input
Port name	V₁, V₂, V₃, V_N
Connector type	Terminal block¹
Wire specification	0.34 – 2.5 mm²(22 – 14 AWG), copper
Wire temp rating	Above 70 ˚C
Measurement catagory	III
Withstand voltage	AC 3,000 V RMS, 60 Hz for 1 minute
Impedance	10 MΩ/phase
Burden	0.01 VA/phase @ 220 V
Wiring method	3P4W, 3P3W, 1P3W, 1P2W
Current Input
Port name	1S, 2S, 3S ports on the power supply side, 1L, 2L, 3L ports on the load side(internal busbar)
Connector type	Terminal block²
Wire specification	2.5 – 6.0 mm²(14 – 10 AWG), copper
Wire temp rating	Above 70 ˚C
Rated current	5 A nominal/10 A full scale 3~ continuous	Accura 3550-5A	per UL 61010, 100 A for 1 second (thermal)
	1 A nominal/2 A full scale 3~ continuous	Accura 3550-1A
Burden	0.01 VA/phase @10 A
Basic Measurement
Frequency measurement	Measuring range	42 – 69 Hz
Basic measurement	Measurement cycle(gapless)	0.2 sec(12 cycles @60 Hz, 10 cycles @50 Hz)
Voltage	Sampling	512 samples/cycle
	Rated voltage (Un)	AC 230 V L–N
	Measuring range(accuracy guaranteed)	35 – 277 V L–N
		60 – 480 V L–L (for unearthed Delta & Y systems)
	Accuracy	±0.2 % Reading	IEC 61557-12 Class 0.2
	Min. measured value	5 V Line–to–neutral
	Measurement data	Line-to-neutral, Line-to-line voltage
		Fundamental, Harmonics(up to the 50th order)³
		Phasor, THD
		Symmetrical components (positive-, negative-, zero-sequence components)
		Unbalance according to symmetrical components/ the NEMA standard
Residual voltage	Measuring method	Calculation of the sum of sampled three–phase line–to–neutral voltages
	Measurement data	RMS, Fundamental
	Accuracy / Operating range	±0.2% Un⁴ / Up to 277 V Line–to–neutral
Current	Sampling	256 samples/cycle
	Measuring range (accuracy guaranteed)	1 % In – 200 % In⁵	Accura 3550-5A
		5 % In – 200 % In⁵	Accura 3550-1A
	Accuracy	±0.2 % Reading	IEC 61557-12 Class 0.2
	Min. measured value	0.1 % In⁵
	Measurement data	Phase current
		Fundamental, Harmonics(up to the 50th order)
		Phasor, THD, TDD
		Symmetrical components (positive-, negative-, zero-sequence components)
		Unbalance according to symmetrical components/the NEMA standard
Residual current	Measuring method	Calculation of the sum of sampled three–phase currents
	Measurement data	RMS, Fundamental
	Accuracy / Operating range	±0.2% In / Up to 200 % of phase current In
Power	Accuracy of active power	IEC 61557–12 Class 0.5
	Accuracy of reactive power	IEC 61557–12 Class 1
	Accuracy of apparent power	IEC 61557–12 Class 0.5
Energy	Active	Accuracy	IEC 62053–22 Class 0.5S
		Type of energy	Received, Delivered, Net, Sum(total) energy
	Reactive	Accuracy	IEC 62053–24 Class 0.5S
		Type of energy	Energy in quadrant 1, 2, 3 and 4
	Apparent	Accuracy	IEC 61557–12 Class 0.5
Demand	Current, Apparent power⁶	Demand, Peak demand, Predicted demand⁷
	Demand time setup	Demand time = Demand sub–interval * the number of demand sub–intervals
Aggregation of Measurement Data
Aggregation intervals	7 fixed intervals	1 and 5 seconds, 1 and 5 minutes, 1 and 6 hours, and 1 day
Aggregation for average value	Average value	Average value of the values measured for 0.2 seconds
	Max/Min value	Max/Min value of the values measured for 0.2 seconds
Aggregation for the latched value⁸	Last latched value	Provides the last measured data by latching the value
Data displayed on the FND screen	Average value	Average value on the values measured for 0.2 seconds (1-second aggregation interval)
	Max/Min value	Max/Min value of the average values for the 1-second aggregation interval after resetting the values
Power Quality
Voltage/current harmonics	Harmonics order	Up to the 50th order
	Measurement data	Magnitude of each harmonic, voltage/current THD, current TDD, Crest factor, K-factor
Voltage/current unbalance	Measurement data	Unbalance according to the NEMA standard
		Negative-/zero sequence unbalance according to symmetrical components
Phasor	Voltage/current	Phasor for the fundamental frequency
Waveform	Voltage/current	12 cycles of waveforms (128 samples/cycle)
Events
Measurement events	Type	Fuse fail, phase open, blackout, and over temperature events
	Event detection / time delay	Determined with the voltage/current data measured for 0.2 seconds (definite time: 1 second)
	Saves 50 measurement events in nonvolatile memory
System events	Events on module control, communication status, setup, etc.
	Up to 1,000 system events can be saved in nonvolatile memory.
IO Module Control
Module control	Maximum number of connectable modules: 2
	Automatically detects the connection status of modules and performs the module ID setup function
	Collects measurement and status data from connected IO modules
Display
FND	1st, 2nd, and 3rd rows	4–digit 7–segment
	4th row	5–digit 7–segment
External Communication with the Host System
Ethernet communication	Protocol	Modbus TCP protocol
	Port	2 ports, Ethernet switching⁹
	Connector type	RJ45 connector
	Communication cable	Ethernet cable Cat 5e FTP, STP, SFTP¹⁰
	Cable length	Up to 100 m
	Communication speed	100 Base–TX(100 Mbps/Full Duplex)
	Wiring mode	Star, daisy chain, ring topology(RSTP¹¹support)
	Max. number of connectable modules	20
RS–485 communication	Protocol	Modbus RTU protocol
	Port	1 port/Ta, Tb
	Connector type	Screw-type terminal
	Communication cable	UL 2919 RS–485 1P/2P 24 AWG
	Cable length	Up to 1,219 m (4,000 ft)
	Communication speed	1,200 / 2,400 / 4,800 / 9,600 / 19,200 / 38,400 / 57,600 / 115,200 bps¹²
	Max. number of connectable modules	32 per bus¹²
Power Supply
Port name	L+, N–
Connector type	Screw-type terminal (pluggable)
Wire specifications	0.25– 4.0 mm² (24 –12 AWG), copper
Wire temperature rating	Above 70 °C
Installation category	CAT II
Operating environment	Pollution degree 2
Withstand voltage	AC 3,000 V RMS, 60 Hz for 1 minute
Power consumption	Max. 4 W when there are no IO modules connected
	Max. 12 W when there are 2 IO modules connected
Power Supply Option	AC/DC 110 - 220 V		DC 48 V
Power supply voltage (Us)¹³	AC 100 – 240 V 50/60 Hz, DC 100 – 300 V		DC 48 V
Operating voltage range	0.9 x Us – 1.1 x Us		0.75 x Us ― 1.3 x Us
Inrush current¹⁴	Peak 31 A, duration no more than 1 msec (AC 220 V)		Peak 5 A, duration no more than 200 μsec (DC 48 V)
	Peak 11 A, duration no more than 200 μsec (DC 110 V)
General
Weight	500 g

1. The maximum tightening torque of the terminal screws of the barrier-type terminal is 1.1 Nm(12 kgf-cm, 10 Ibf-in).
2. The maximum tightening torque of the terminal screws of the barrier-type terminal is 1.4 Nm(14 kgf-cm, 12 Ibf-in).
3. The measured harmonic component indicates the magnitude of the line-to-neutral voltage in 3P4W mode and the magnitude of line-to-line voltage in 3P3W mode.
4. The rated voltage Un is 280V Line–to–Neutral.
5. The rated current In is 5 A/1 A.
6. For active power demand, Received or Net active power can be selected.
7. The predicted demand is calculated based on the thermal demand, and the response speed for thermal demand can be set.
8. For specific measurement parameters including energy, demand, and IO modules’ digital input and output data, the device provides the data measured for the last 0.2 seconds by latching the data.
9. The built-in switch allows for Ethernet connection between Accura 3550 devices, without the need for an external switch.
10. FTP(Foiled Shield Twisted Pairs), STP(Braided Shield Twisted Pairs), SFTP(Braided Foiled Shield Twisted Pairs)
11. RSTP(Rapid Spanning Tree Protocol), IEEE 802.1D-2004.
12. At 115,200 bps, a master can communicate with up to 16 slave devices, and the maximum distance between the master and the slave is 600 m.
13. The device conforms to UL standards for the tested AC power supply voltage.
14. When installing a fuse at the voltage input line, it is recommended to use a fuse above 2 A/500 V due to inrush current.

General Specifications of IO Modules

DC 0–20mA Analog Input
Item	Description
Connector type	Screw–type terminal(pluggable)
Wire specification	0.25 – 4.0 mm² (24 – 12 AWG), max 0.51 Nm (5.2 kgf–cm, 4.5 Ibf–in)
Input type	Internal DC 24 V power supply(external excitation)
Current draw	1st channel: 10 mA, other channels: 5 mA
Insulation	Max. AC 2,000 V 1 minute
Min. pulse width	100 msec (settable)
Digital Output
Item	Description
Connector type	Screw–type terminal (Pluggable)
Wire specification	0.25 – 4.0 mm² (24 – 12 AWG), max 0.51 Nm (5.2 kgf–cm, 4.5 Ibf–in)
Output type	Dry contact(external excitation)
Maximum Rating	AC/DC 240 V 350 mA (max. 1 A)¹
Insulation	Max. AC 3,000 V for 1 minute
Output signal type	Latch, pulse, energy pulse
Minimum pulse cycle	20 msec
Minimum pulse width	10 msec
DC 0–20mA Analog Output
Item	Description
Connector type	Screw–type terminal (pluggable)
Wire specification	0.25 – 4.0 mm² (24 – 12 AWG), max 0.51 Nm (5.2 kgf–cm, 4.5 Ibf–in)
Input type	DC current 0 – 20 mA
Internal input resistance	150 Ω
DC 0–20mA Analog Output
Item	Description
Connector type	Screw–type terminal (pluggable)
Wire specification	0.25 – 4.0 mm² (24 – 12 AWG), max 0.51 Nm (5.2 kgf–cm, 4.5 Ibf–in)
Output type	DC Current 0 – 20 mA
Allowable load resistance	No more than 450 Ω

1. It indicates the Peak AC or DC value. Max. 1 A indicates current flowing once during a current–carrying time of 100 ms.

Specifications of Individual IO Modules

DC Module
DC voltage/current input
Number of channels	3
Port name	I_OUT+ I_OUT– / I_BAT+ I_BAT– / V_DC+ V_DC–¹
DC Shunt resistance	Max. DC 100 mV		Full scale: 100 mV
DC Voltage	Max. DC 200 V		Full scale: 200 V
Accuracy	±0.5 % Full Scale
Min. measured value	0.5 % Full scale
Digital Input			Digital Output
Number of channels	4(redundant circuits per channel)²		1
Port name	DI₁ DI₂ DI₃ DI₄ DI_G³		DO DO_G
DIO Module
Digital Input			Digital Output
Number of channels	8 (redundant circuits per channel)²		2
Port name	DI₁ DI₂ DI₃ DI₄ DI_G / DI₅ DI₆ DI₇ DI₈ DI_G³		DO₁ DO_1G / DO₂ DO_2G⁴
DI Module
Digital Input
Number of channels	12 (redundant circuits per channel)²
Port name	DI₁ DI₂ DI₃ DI₄ DI_G / DI₅ DI₆ DI₇ DI₈ DI_G / DI₉ DI₁₀ DI₁₁ DI₁₂ DI_G²
DO Module
Digital Output
Number of channels	6
Port name	DO₁ DO_1G / DO₂ DO_2G / DO₃ DO_3G / DO₄ DO_4G / DO₅ DO_5G / DO₆ DO_6G⁴
AI Module
Analog Input
Number of channels	6
Port name	AI₁ AI_1G / AI₂ AI_2G / AI₃ AI_3G / AI₄ AI_4G / AI₅ AI_5G / AI₆ AI_6G⁵
AO Module
Analog Output
Number of channels	6
Port name	AO₁ AO_1G / AO₂ AO_2G / AO₃ AO_3G / AO₄ AO_4G / AO₅ AO_5G / AO₆ AO_6G
A4D2 Module
Analog Output			Digital Output
Number of channels	4		2
Port name	AO₁ AO_1G / AO₂ AO_2G / AO₃ AO_3G / AO₄ AO_4G		DO₁ DO_1G / DO₂ DO_2G³
Accuracy	±0.5 % Full scale	Full scale: 20 mA	-
A2D4 Module
Analog Output			Digital Output
Number of channels	2		4
Port name	AO₁ AO_1G / AO₂ AO_2G		DO₁ DO_1G / DO₂ DO_2G / DO₃ DO_3G / DO₄ DO_4G⁴
Accuracy	±0.5 % Full scale	Full scale: 20 mA	-
RTD Module
RTD Analog Input
Number of channels	a₁ A₁ B₁ b₁ / a₂ A₂ B₂ b₂ / a₃ A₃ B₃ b₃
RTD sensor	PT100, PT1000
Wiring method	4-wire, 3-wire, 2-wire connection
Accuracy	±0.5 % Full Scale		Range: –100 to 200 °C, Full Scale: 200 °C
Min. measured value	0.5 % Full scale
ELD Module
ZCT Analog Input			Digital Output
Number of channels	6		1
Port name	Z₁ Z_1G / Z₂ Z_2G / Z₃ Z_3G / Z₄ Z_4G / Z₅ Z_5G / Z₆ Z_6G⁵		DO, DOG
Leakage current input	Voltage output type ZCT 200 mA/100 mV @ 1.2 kΩ burden⁶
Accuracy	±0.5 % Full Scale	200 mA/100 mV, Range: 0 – 2 A, Full Scale: 2 A
Min. measured value	0.5 % Full scale
TEMP Module
RJ45 communication port	Used to connect the TEMP module to Accura TSEN/THSEN
Connector type	RJ45 connector
Protocol	Dedicated protocol of the manufacturer
Connection with Accura TSEN/THSEN⁶	Can be connected with up to 6 Accura TSEN/THSEN devices in a daisy chain at a maximum distance of 100 m.⁷
Accura TSEN/THSEN
RJ45 communication port	Port name	RJ45A, RJ45B(The ports have the same function.)
	Connector type	RJ45 connector
	Protocol	Dedicated protocol of the manufacturer
	Communication cable	Ethernet cable Cat 5e FTP, STP, SFTP⁸
	Cable length	Max. 100 m
	Accura TSEN/THSEN ID	ID available for communication	1 – 6
		Standby ID	0 (default value, communication unavailable)
LED	Green	Blinks when the module operates normally
Power supply	Supply method	Receives power from the TEMP module via the RJ45 communication cable
Accura TSEN
Temperature measurement	Temperature sensor	Located at the bottom end of the device
	Accuracy	Typ. ±1.0 °C
	Measuring range	–20 – 100 °C
	Response time [τ 63%]	Max. 30 seconds
Accura THSEN
Temperature/humidity measurement	Temperature/humidity sensor	Located at the bottom end of the device
	Accuracy	Temperature	Typ. ±1.0 °C
		Humidity	Typ. ±2.0 %RH @°C
	Measuring range	Temperature	-20 ― 100°C
		Humidity	0 ― 100 %RH
	Response time [τ 63%]	Max. 8 seconds

1. The inputs of each channel features differential inputs, and the common-mode voltage should be no more than 200 V.
2. Each channel features redundant circuits. Thus when two inputs differ, the module processes the event as a redundancy error and provides maintenance notifications.
3. The DIG ports are internally connected and are the common ground ports of all channels.
4. Each DO channel is electrically insulated.
5. The inputs of each channel features differential inputs, and the common–mode voltage should be less than 2 V.
6. The internal resistance(default: 1.0 kΩ) and burden resistance of the ZCT(default: 1.2 kΩ) can be set up.
7. The communication cables used to connect the TEMP module to Accura TSEN/THSEN devices are not provided.
8. FTP(Foiled Shield Twisted Pairs), STP(Braided Shield Twisted Pairs), SFTP(Braided Foiled Shield Twisted Pairs)

General Specifications

Environmental Conditions
Installation location	Indoors
Operating temperature	–20 – 70℃(–4 – 158℉)
Operating environment	Pollution degree 2
Safe operating temperature ¹	–20 – 60℃(–4 – 140℉)
Storage temperature	–40 – 85℃(–40 – 185℉)
Operating humidity	5 – 95%(non–condensing)
Operating altitude	Up to 2,000 m
Ingress protection against dust and water	IEC 60529 IP54(Accura 3550)
General
Warranty Period	2 years