Announcement

Sep/27/2011The notice of failure on the TOS5300 Series

We would like to take this opportunity to thank you for doing business with us.

This is to inform you that we have discovered the considerable failure on the model TOS5300, TOS5301, and TOS5302. The discovered failure may cause to the significant error in the accuracy of the ammeter while doing the withstanding voltage test, the measured value may become beyond the specification range when the unit is used under the specified condition.
We would like to confirm the description of failure and our countermeasure against the defective unit.

We deeply regret the inconvenience that this might have caused in your business.

We hereby commit ourselves to strive and take corrective action and preventive measures against a reccurence of such failures on our products.

Sincerely Yours,
KIKUSUI AMERICA, INC.

1.Applied products

Descriptions	Model name	Serial numbers
AC Withstanding Voltage Tester	TOS5300	QK000867-QK002987 QM001932-QM002731 RC002438-RC002447 RD002985-RD002994 RE002110-RE002817 RF002361-RF002370 RH002277-RH002281
AC/DC Withstanding Voltage Tester	TOS5301	QK000870-QK002982 QM001942-QM003633 RD001799-RD002984 RE002150-RE002155 RF002154-RF004325
AC Withstanding Voltage / Insulation Resistance Tester	TOS5302	QK000873-QK002977 QL002997-QL003016 QM003385-QM003414 RC001522-RC003000 RD002286-RD002552 RE001426-RE001481 RF002306-RF004396 RG002945-RG002970

2.The description of failure

When the unit is operated under the line voltage between 160V and 250V, the error of the current measurement may become 3% to 30% in the measuring range of between 13mA to 50mA, in such case the error level is far beyond the specification limit. This occurane directly relates to affect the judgment accuracy of the shut down current. The failure has not been discovered in the entire production, however it has been occured around 30% of the production. Unless otherwise specified above, we have found no problem on any other measuring current range, the DC withstanding voltage test, and the insulatioan resistance test.

3.The cause of failure and the counter measure

The failure was discovered in the IC used for the internal power supply of which design was not appropriately to remain the limit of quality variation of the characteristics of the IC, and some of the cases were found that the internal reference has been shifted due to the variation of line voltage. The countermeasure shall conduct to change two locations of the circuit constant of the internal power supply for the entire unit specified in the aforementioned list.

4.Support for the unit in the customer's possession

For those units which are in the customer's possession, we shall manage to send our local service representative to conduct the repair service at free of charge. In addition, the calibration value shall not be affected by this modification. Should you have any questions, please contact with our local sales office.