R9 Series Power Monitoring Unit
for Multi-channel Online & Offline Data Logging

model: R9xWTU
  model: R9xWTU  
  • Basic unit can measure up to 8 heavy current circuits on a common voltage input.
  • Single-phase/2-wire and 3-wire, and three-phase/3-wire system use
  • Easy setup with clamp-on current sensors for input
  • Flexible range of 5 to 600 A input
  • Time-stamped data logging in SD card
  • Extension unit for eight additional current circuits or 8 discrete I/O can be attached.
Model Network Function Spec
R9EWTU Modbus TCP (Ethernet) PDF


Multi-channel Power Monitoring
Discrete I/O extension unit
model: R9WTU-EP model: R9WTU-ED
  • Specification Sheet
  • Specification Sheet

The R9 Series Power Monitoring Unit is a compact all-in-one module that can measure up to 8 heavy current circuits with a common voltage input. An extension unit for additional 8 circuits (model: R9WTU-EP) can be attached to the side of basic unit. At the maximum of 16 measuring input unit provides for cost-effective multi-channel power monitoring solution for office buildings and manufacturing plants.

A discrete I/O extension unit (model: R9WTU-ED) is also available for 8 pulse inputs and 8 contact outputs. Pulse count signals such as gas/air pressure and water flow from other utility equipment, and production unit count signals can be taken in all together to the R9 unit for use with energy consumption rate calculation and energy efficiency improvement analysis of an entire manufacturing line.

Clamp-on Current Sensor Input
model: CLSE
  model: CLSE  
  • Specification Sheet

Current sensors that can take in a flexible range of 5 to 600 amperes directly to the unit can be fitted easily without need of extensive installation work. They are purchased independently to minimize introduction cost of the energy monitoring system that can be expanded later when more measuring points are needed.

Offline Monitoring
SD memory card slot

The unit is equipped with a SD memory card slot. Data stored in its internal memory are transferred to the card at 0 minute every hour. A 4-GB SD memory can store information of 8 channels for approximately 16 years.

Energy (watthour) and pulse count input data per hour for each channel are stored with date/time. Voltage, current and power in addition to energy and pulse count per minute are also stored. All data are exported to the SD memory card every hour and saved in a CSV format file.

Online Monitoring

Modbus RTU, Modbus/TCP, CC-Link or LONWORKS Modbus RTU, Modbus TCP (Ethernet), CC-Link or LONWORKS interface types are available as standard. All parameters can be polled from a SCADA system on the PC: current, voltage, active/reactive/apparent power, power factor, frequency, active/reactive/apparent energy, harmonic distortion and date/time.

Contact outputs at the discrete extension I/O unit can be controlled from the host via the network for alarm and external count purposes.

Configuration Single-phase/2-wire and 3-wire, three-phase/3-wire
Voltage input Delta voltage: 400V AC (line to line)
Phase voltage: 230V AC (line to neutral)
Selectable primary range: 50 to 400000V
Current input

Clamp-on current sensor model CLSE: 5A, 50A, 100A, 200A, 400A and 600A
Selectable primary range: 1 to 20000A

Auxiliary power supply 100-240V AC or 110-240V DC
Operating temperature -10 to +55°C (14 to 131°F)
Operating humidity 30 to 90% RH (non-condensing)
Mounting Surface or DIN rail
Accuracy (except current sensor accuracy) Voltage, current, power: ±0.5% of rating
Energy: ±1%
Power factor: ±1.5%
Frequency: ±0.1% of rating
Harmonic contents: ±2% of rating
Sampling time Harmonic contents & frequency: 1 sec. or less
Other: 500 msec. or less
Insulation resistance 100 MΩ or more with 500V DC
Dielectric strength 1500V AC @1 minute
Dimensions Basic unit: 125x122x80 mm (4.92”x4.80”x3.15”)
Extension unit: 93x122x80 mm (3.66”x4.80”x3.15”) when attached to the basic unit
(DIN rail mount)
Recommended SD card Hagiwara Sys-Com NSDA-004GT
Apacer Technology AP-ISD04GIS4B-T
Application Example
Product Cost Analysis
Building Energy Management System (BEMS)
Product Bulletins (R9 Series)
A4: PDF Letter: PDF
Data Sheet