• YOKOGAWA

CW120 and CW121, Precision Power Clamp-on Meters
Maintenance and long term monitoring of electrical equipment and electrical systems

As energy conservation becomes increasingly important, we are pleased to present low-cost clamp-on power meters designed to meet user needs for simple tools capable of measuring power values and instantaneous values

Yokogawa CW120 Clamp-on Power Analyzers
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Features

  • Compact & Light weight body with large back-lit LCD
  • Current clamps in a range of sizes(small to large diameter)
  • Support for large-capacity ATA flash memory (equipped with PC card slot)
  • Wiring error check function
  • 2 or 3-load system
  • Simultaneous measurement of multiple use possible by external control terminal
  • Parameters setting tool is included to set measurement conditions through PC
  • IIII [+] more
    • Periodically save data as often as once a second

      Data can be saved as low as 1-second interval. This capability allows the CW120 Series to respond quickly to load fluctuations and measure transient responses in equipment
    • Check equipment operating conditions

      The CW120 Series has an instantaneous value filing function (enabling multiple data records to be saved in a single file when multiple measurements are taken) which is useful for determining equipment operating conditions
    • Works even with small electric energyvalues

      Easily change the decimal position (the number of digits following the decimal point) and display unit (Wh,kWh, MWh, GWh) on the electric energy display
    • Load measurements on multiple systems

      In addition to support for a variety of connection types, The CW120 Series can simultaneously measure the loads* (facilities, equipment) on multiple systems sharing a common power supply.
      CW120 (three-phase 3-wire model): 1Ø2W X2
      CW121 (three-phase 4-wire model): 1Ø2WX2, X3

Measurements

  • Input System: Single-phase 2-wire to 3-phase 3-wire (CW120), 3-phase 4-wire (CW121) Measurement Functions: Voltage, Current, Frequency, Active power, Reactive power, Power factor, Active electric energy, Regenerative electric energy
  • Continuous measurement integration (accurate measurements can be obtained even if there are large load fluctuations)
  • Plus/minus signs are shown for reactive power and power factor.
  • Power Supply Quality Check

Description

The Yokogawa CW120/CW121 power meter is a Low-cost tool designed to support your energy conservation efforts. The CW120/CW121 monitors data and saves it in 1-second intervals. This capability allows the CW120 Series to respond quickly to load fluctuations and measure transient responses in equipment. An instantaneous value filing function (enables multiple data records to be saved in a single file when multiple measurements are taken). This function helps ensure that measurements are correct, ideal for determining equipment operating conditions.

In addition to supporting a wide variety of connection types, The CW120 Series can simultaneously measure the loads (facilities, equipment) on multiple systems sharing a common power supply.
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Not only can the CW120/CW121 simultaneous measure multiple facilities, multiple units can start and stop integration simultaneously through externally controlled I/O. The CW120/CW121 power meter works with small electric energy values. The decimal position (number of digits following the decimal point) and the display unit (Wh, kwh,MWh, GWh) are featured on the electric energy display.

The setting software allows you to set CW120 Series measurement conditions through a PC and save measurement data on a PC when the unit is connected to the PC through RS-232 or RS-485 port. This function makes it easy to set basic functions needed for measurement, such as start/stop time and date, wiring method, clamp type, voltage, and current range etc. The data file stored in CF pack can be transfered to PC. Microsoft Excel can read transferred data file.

In addition to proprietary communication the CW120/CW121 also supports, MODBUS, PC-link and Power Monitor protocols. PC-link is a protocol for Yokogawa’s Temperature controllers and PLCs. Power Monitor protocol is a protocol for Yokogawa’s Power Monitors. The RS-485 allows multiple use to be connected for remote monitoring.

  • Literature
  • Specifications
Literature and Technical Information
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Test and Measurement

++ CW120 Clamp-on Power Analyzer | Brochure (1 MB)
Model: Yokogawa CW120and CW121 Power Clamp-on Meter
parameter Voltage Current
Input type Resistive potential division Clamp detection
Rated value
(range)
150.0 V
300.0 V
450.0 V
Varies with the clamp and range used.
96033 (50A) 5.000/10.00/20.00/50.00 A
96030 (200A) 20.00/50.00/100.0/200.0 A
96031 (500A) 50.00/100.0/200.0/500.0 A
96032 (1000A) 200.0/500.0 A/1.000 kA
Wiring CW120 Single-phase 2-wire, single-phase 3-wire, three-phase 3-wire
CW121 Single-phase 2-wire, single-phase 3-wire, three-phase 3-wire, three-phase 4-wire
Maximum allowed
input
495 Vrms Clamp 96033: 130 Arms
Clamp 96030: 250 Arms
Clamp 96031: 625 Arms
Clamp 96032: 1000 Arms
A/D converter Voltage/current input simultaneous conversion, 12-bit resolution
Resistance
CW120 Approximately 1.5 MΩ Approximately 100 kΩ
CW121 Approximately 1.3 MΩ
Measurement Input functions
parameter Voltage Current/active power
Method: Method
Frequency range: 45–65 Hz (reciprocal system), detected from V1
Active input range: 10–110% of each range
Temperature coefficient: ±0.05% rng/°C
Display updating interval: Approximately one second
Crest factor
Lower limit: 1000 Vrms Rated input: 3
Upper limit: Rated input: 1.56
Display range
150/300 V range: All ranges 1.5 V 0.4% of each range
450 V range: 130% of each range, except 110% for 450 V range 130% of each range

|||| Click to View Measurement Accuracy

Instantaneous Value Measurement
Accuracy
Voltage: ±(0.3% rdg + 0.2% rng)
Current/active power: ±(0.8% rdg + 0.4% rng) when using clamps 96030, 96031, and 96033
±(1.2% rdg + 0.8% rng) when using clamp 96032
Frequency: ±(0.1% rdg + 1% dgt)
Computation
Parameters: Voltage rms (V), current rms (A), active power (W), frequency (Hz)
Accuracy: (value calculated from measurement) ±1 dgt
PF influence: ±1.0% rng cosø = ±0.5 (relative to power factor 1) when using clamp 96030
±2.0% rng cosø = ±0.5 (relative to power factor 1) when using
clamps 96031, 96032, and 9603
RF influence: ±1.0% rng sinø = ±0.5 (relative to reactive factor 1) when using
clamp 96030
±2.0% rng sinø = ±0.5 (relative to reactive factor 1) when using
clamps 96031, 96032, and 9603
Electric Energy Measurement
Measured parameters: Active electric energy, regenerative electric energy (regenerative electric energy is not displayed on the screen; it is merely saved)
Measurement accuracy: Active power measurement accuracy ±1 dgt (with standard settings)
Integration function settings: Start/stop settings: Manual, timer, external trigger (control)
Output intervals: 1/2/5/10/15/30 seconds; 1/2/5/10/15/30 minutes; 1 hour

|||| Click to View Specifications (cnt’d)

Display Functions
Display screen: Backlit segmented LCD
Energy Function: 6 digits
Other parameters: 4 digits
Communication
Electrical specifications: Conforms to EIA RS-232 or EIA RS-485.
Protocols: CW120/121 proprietary protocol, Power Monitor protocol
(Standard protocol used for YOKOGAWA M&C’s Power Monitor)
PC link communication (Standard protocol used for YOKOGAWA M&C’s Temperature Controllers)
MODBUS communication (ASCII or RTU)
Synchronization system: Start stop synchronization
 
External Control I/O (for RS-232 only; not provided for RS-485): These input and output can be used as signals for starting and stopping integrating measurement.
•Control input: TTL level or contact
•Control output: TTL level
Faulty Wiring Checking Functions: Check details:
Presence/absence of power input; check for frequency measurement range; voltage phase sequence;
presence/absence of power input; whether current clamp is reverse-connected
Scaling Function: The VT ratio and CT ratio can be set.
•Settings ranges:
VT ratio: 1–10,000
CT ratio: 1–10,000 (in increments of 0.01)
Environment
Insulation: 500 V DC, 50 MW or greater Between voltage input terminals and case Between voltage input terminals and current input terminals, communication terminals, and control
I/O terminals
Between power line and case
Between power line and current input terminals, communication terminals, and control I/O terminals
Withstand voltage: 5550 V AC for one minute
Between voltage input terminals and case
3320 V AC for one minute
Between voltage input terminals and current input terminals, communication terminals, and control I/O terminals
2300 V AC for one minute
Between power line and case
Between power line and current input terminals, communication terminals, and control I/O terminals
Power Supply: 100–240 V AC ±10%, 50/60 Hz
Operating Temperature: 0–50°C, 5–85% RH (no condensation)
0–40°C, 5–85% RH (no condensation) for UL, C-UL
Storage Temperature: -20–60°C, 90% RH (no condensation)
Dimensions: Approximately 117 x 161 x 51 mm (W x H x D)
Weight: Approximately 0.6 kg
Safety standards: Compliant with EN61010-1, EN61010-2-031, UL3111-1 First Edition, CAN C22.2 No. 1010.1-92
- Voltage input line:
Measurement (Overvoltage) category III (Max. input voltage : 600 Vrms)
- Power line:
Installation category II (Max. input voltage : 264 Vrms)
EMC (emission): Compliant with EN55011, Group1, ClassA; EN61326; EN61000-3-2; EN61000-3-3
EMC (immunity): Compliant with EN61326