YOKOGAWA CW500 Power Quality Analyzer

Current input terminals: A1/A2/A3/A4, connected to clamp probes. Unused current terminals can only measure effective values and harmonics.

Power interface: Connect a dedicated power cord and support wide voltage input of 100-240VAC.

(3) Side and back

Side: SD card slot (supporting 2GB SD card), USB Type-B interface (connected to PC), analog input terminal (2-channel, ± 11VDC, monitoring temperature sensor and other signals), digital output terminal (open collector, outputting low level when power quality event triggers).

Back: Battery cover (6 AA batteries), instrument serial number label (to be provided when contacting the dealer).

2. Probe and wiring identification

Voltage probe: equipped with a safety barrier (to avoid finger crossing), connected to the tested circuit at the crocodile clip end, and connected to the instrument voltage terminal at the other end. It needs to be matched with the ID marked color (such as red connected to V1, blue connected to VN).

Clamp probe: The direction of the arrow should be consistent with the current flow direction (otherwise the polarity of the active power will reverse), supporting a range of 2A~3000A. When connecting, it should be aligned with the arrow mark on the instrument current terminal.

Basic operation process

1. Power supply mode setting

(1) Battery powered

Confirm that the instrument is powered off, use a Phillips screwdriver to open the back battery cover, and insert 6 AA alkaline batteries (or nickel hydrogen rechargeable batteries) according to polarity.

Close the battery cover and tighten the screws. After turning on, the battery icon will be displayed at the top of the screen, with 4 bars indicating full charge and 1 bar indicating low battery (needs to be replaced in a timely manner).

Attention: Nickel hydrogen batteries need to be charged with a dedicated charger, and the instrument does not support charging function; Long term disuse requires removing the battery to avoid leaking and damaging the instrument.

(2) AC power supply

Confirm that the instrument is powered off, connect one end of the power cord to the top power interface of the instrument, and plug the other end into a socket that meets local standards (100-240VAC, 50/60Hz).

After booting up, the AC power icon is displayed at the top of the screen, with a maximum power consumption of approximately 7VA.

2. Preparation before measurement

(1) Paste terminal board and ID mark

Select the input terminal board that matches the wiring color from the accessories (such as TYPE 1: VN=blue, V1=red, V2=green), clean the top terminal area of the instrument, and paste it.

Paste the ID tag on both ends of the probe to ensure consistency with the terminal color (such as connecting the red probe to the V1 terminal), to avoid wiring errors.

(2) SD card installation

Open the side SD card slot cover, insert the SD card face up (hear a "click" sound to indicate installation), and close the slot cover.

The new SD card needs to be formatted on the instrument (through the SETUP menu), as formatting on a PC may result in abnormal recording; Stop recording before removing the SD card to avoid data damage.

3. Wiring and measurement startup

Taking the "three-phase four wire (3P4W)" wiring as an example, the process is as follows:

Power off confirmation: Ensure that the tested circuit is powered off, remove the instrument power supply and probe.

Voltage wiring: Connect the voltage probe crocodile clip to VN (neutral wire) and V1/V2/V3 (phase wire) respectively, and insert the other end of the probe into the instrument VN and V1/V2/V3 terminals.

Current wiring: Clamp the clamp probe on the outside of the V1/V2/V3 phase line (arrow pointing towards the current flow direction), and insert the probe plug into the A1/A2/A3 terminals accordingly.

Power on and setup: Press and hold the power button to turn on the device, press the SETUP button to enter "Basic Setup", select the wiring system as "3P4W", confirm the voltage range (default 600V), and current clamp model (e.g. 96064 is 500A).

Start recording: Press the START button, the status LED green light stays on, the screen displays "REC", and start recording measurement data; Press the STOP button to stop recording, and the data will be automatically saved to the SD card.

4. Data display and operation

(1) Key function key operation

W/Wh key: Switch between displaying instantaneous values (voltage, current, power), integrated values (electrical energy Wh, varh), and demand values (DEM Target/Guess/Max).

Vector key: Display voltage/current vector diagram, check if the wiring phase is correct (e.g. three-phase voltage phase difference should be 120 °).

Waveform key: Display real-time voltage/current waveforms, switch channels using the directional keys, and adjust the time scale by pressing the F2 key (e.g. 5ms/div).

Harmonic key: displays the harmonic analysis results (1st to 50th harmonics), including THD (total harmonic distortion) and the percentage of voltage/current for each harmonic.

QUALITY key: displays the record of power quality events, such as the occurrence time and value of sudden rise (default 110% rated voltage), sudden drop (default 90% rated voltage), and interruption (default 10% rated voltage).