Browse wiki
Jump to navigation
Jump to search
The following is a synopsis of a Part 21 i … The following is a synopsis of a Part 21 interim report received by email:</br>COMPONENT DESCRIPTION - 300V, 250 A clamp diodes with Vishay/International Rectifier part numbers IN3737 and IN3737R and Ametek part numbers 07-600250-00 and 07-600251-00, respectively. Diode failures occurred in 20kVA Inverters, Ametek part number 85-VC0200-41 with serial numbers C84733-0211 and C84733-0511. Two failed diodes returned for evaluation were manufactured in India in 2004. </br>PROBLEM EXPERIENCED - TVA has experienced 5 diode failures since November of 2017. The diode failures experienced at TVA resulted in alarms for abnormal conditions and equipment alarms for fan failure, inverter fuse blown, and inverter failure. The equipment will transfer to bypass when a diode fails. </br>POTENTIAL CAUSE - Diodes installed in the TVA equipment were shorted in most cases and degraded in one instance. Only two of the shorted diodes were sent to AMETEK SCI for evaluation. </br>While the precise cause of this failure is unknown, diode failures are generally attributed to transient voltage spikes and overheating. TVA did indicate there have not been any transient events on the DC bus that could have caused this failure. </br>The inverters at TVA are loaded below 50%. This could contribute to increased heat and stress on the diodes due to increased current draw. However, test data from the original testing of the equipment at no load did not show elevated temperatures on the diodes. </br>EFFECT ON SYSTEM PERFORMANCE - Failures described above could result in loss of output voltage and transfer of the static switch to the bypass source which could result in potential loss of load. </br>EVALUATION OF THE POTENTIAL DEFECT - AMETEK is sending the parts to the original manufacturer for further evaluation with the intent to obtain more insight on the interior condition of the diodes. The targeted completion date for this evaluation of the two diodes returned is June 1, 2021.</br>* * * UPDATE FROM ETHAN SALSBURY TO DONALD NORWOOD AT 0648 EDT ON 4/6/2021 VIA E-MAIL* * *</br>What is being classified as a 'minor adjustment' is being made to the notification originally submitted on 4/1/2021.</br>All diodes TVA identified as failed were shorted. None were degraded.</br>Notified R2DO (Miller) and the Part 21/50.55 Reactors E-mail group.</br>* * * UPDATE FROM ETHAN SALSBURY TO THOMAS HERRITY AT 1145 EST ON 02/11/2022 VIA EMAIL * * *</br>The following excepts provide a synopsis of information provided by AMETEK in the final report. </br>... The failure was caused by electrical overstress, but the specific root cause is indeterminate.</br>PROBLEM YOU COULD SEE: A diode failure could occur and will result in the equipment transferring to bypass, a loss of output voltage, blown fuses, and unexpected alarms such as fan failure, inverter fuse blown, and inverter failure alarms. There are no conclusive warning signs that a failure is imminent, or detection method for predicting an approaching failure. </br>CAUSE: Diodes that failed in the TVA equipment were shorted according to the summaries provided by TVA. Only two of the shorted diodes were sent to AMETEK SCI for evaluation. The condition of all other diodes is unknown. </br>While the precise cause of this failure is unknown, diode failures are generally attributed to transient voltage spikes and overheating. TVA did indicate there have not been any transient events on the DC bus that could have caused this failure. Additionally, AMETEK sent a representative to the site to review the equipment and operating conditions. The field service technician concluded that there were no abnormalities apparent in the operating conditions or the equipment itself. </br>According to TVA, the inverters at TVA are loaded below 50%. The AMETEK field service representative determined load was at 25% of full load during the site visit in August of 2021. This could contribute to increased heat and stress on the diodes due to increased current draw. However, there was no indication of overheating of the diode at no load or 25% of unit C84733- 0511 (1-II). All diodes were within acceptable temperature conditions on the equipment evaluated. </br>EFFECT ON SYSTEM PERFORMANCE: Failures described above could result in loss of output voltage and transfer of the static switch to the bypass source which could result in potential loss of load. </br>ACTION REQUIRED: AMETEK Solidstate Controls recommends that each facility evaluate the potential risk and performs replacement as determined necessary. Evaluation could include oscilloscope measurements across the diodes and temperature measurements of the diodes and the equipment. Voltage readings from the oscilloscope measurement should not exceed the rating of the diode. Temperatures should be compared to original test data and should not exceed 100ø C. </br>Recent evaluations have been unable to pinpoint a failure mode and there are no conclusive connections to previous failures. Only the failures provided in this report have surfaced for the subject part numbers and the failure rate has been low. </br>AMETEK SOLIDSTATE CONTROLS CORRECTIVE ACTION: AMETEK Solidstate Controls will work with you to arrange replacements and spare parts for your application as needed. Please contact our Client Services group at 1-800-222-9079 or 1- 614-846-7500, extension 1.</br>Notified R2DO (Miller) and the Part 21/50.55 Reactors E-mail group. 21/50.55 Reactors E-mail group.
04:00:00, 1 April 2021 +
17:20:00, 1 April 2021 +
04:00:00, 1 April 2021 +
The following is a synopsis of a Part 21 i … The following is a synopsis of a Part 21 interim report received by email:</br>COMPONENT DESCRIPTION - 300V, 250 A clamp diodes with Vishay/International Rectifier part numbers IN3737 and IN3737R and Ametek part numbers 07-600250-00 and 07-600251-00, respectively. Diode failures occurred in 20kVA Inverters, Ametek part number 85-VC0200-41 with serial numbers C84733-0211 and C84733-0511. Two failed diodes returned for evaluation were manufactured in India in 2004. </br>PROBLEM EXPERIENCED - TVA has experienced 5 diode failures since November of 2017. The diode failures experienced at TVA resulted in alarms for abnormal conditions and equipment alarms for fan failure, inverter fuse blown, and inverter failure. The equipment will transfer to bypass when a diode fails. </br>POTENTIAL CAUSE - Diodes installed in the TVA equipment were shorted in most cases and degraded in one instance. Only two of the shorted diodes were sent to AMETEK SCI for evaluation. </br>While the precise cause of this failure is unknown, diode failures are generally attributed to transient voltage spikes and overheating. TVA did indicate there have not been any transient events on the DC bus that could have caused this failure. </br>The inverters at TVA are loaded below 50%. This could contribute to increased heat and stress on the diodes due to increased current draw. However, test data from the original testing of the equipment at no load did not show elevated temperatures on the diodes. </br>EFFECT ON SYSTEM PERFORMANCE - Failures described above could result in loss of output voltage and transfer of the static switch to the bypass source which could result in potential loss of load. </br>EVALUATION OF THE POTENTIAL DEFECT - AMETEK is sending the parts to the original manufacturer for further evaluation with the intent to obtain more insight on the interior condition of the diodes. The targeted completion date for this evaluation of the two diodes returned is June 1, 2021.</br>* * * UPDATE FROM ETHAN SALSBURY TO DONALD NORWOOD AT 0648 EDT ON 4/6/2021 VIA E-MAIL* * *</br>What is being classified as a 'minor adjustment' is being made to the notification originally submitted on 4/1/2021.</br>All diodes TVA identified as failed were shorted. None were degraded.</br>Notified R2DO (Miller) and the Part 21/50.55 Reactors E-mail group.</br>* * * UPDATE FROM ETHAN SALSBURY TO THOMAS HERRITY AT 1145 EST ON 02/11/2022 VIA EMAIL * * *</br>The following excepts provide a synopsis of information provided by AMETEK in the final report. </br>... The failure was caused by electrical overstress, but the specific root cause is indeterminate.</br>PROBLEM YOU COULD SEE: A diode failure could occur and will result in the equipment transferring to bypass, a loss of output voltage, blown fuses, and unexpected alarms such as fan failure, inverter fuse blown, and inverter failure alarms. There are no conclusive warning signs that a failure is imminent, or detection method for predicting an approaching failure. </br>CAUSE: Diodes that failed in the TVA equipment were shorted according to the summaries provided by TVA. Only two of the shorted diodes were sent to AMETEK SCI for evaluation. The condition of all other diodes is unknown. </br>While the precise cause of this failure is unknown, diode failures are generally attributed to transient voltage spikes and overheating. TVA did indicate there have not been any transient events on the DC bus that could have caused this failure. Additionally, AMETEK sent a representative to the site to review the equipment and operating conditions. The field service technician concluded that there were no abnormalities apparent in the operating conditions or the equipment itself. </br>According to TVA, the inverters at TVA are loaded below 50%. The AMETEK field service representative determined load was at 25% of full load during the site visit in August of 2021. This could contribute to increased heat and stress on the diodes due to increased current draw. However, there was no indication of overheating of the diode at no load or 25% of unit C84733- 0511 (1-II). All diodes were within acceptable temperature conditions on the equipment evaluated. </br>EFFECT ON SYSTEM PERFORMANCE: Failures described above could result in loss of output voltage and transfer of the static switch to the bypass source which could result in potential loss of load. </br>ACTION REQUIRED: AMETEK Solidstate Controls recommends that each facility evaluate the potential risk and performs replacement as determined necessary. Evaluation could include oscilloscope measurements across the diodes and temperature measurements of the diodes and the equipment. Voltage readings from the oscilloscope measurement should not exceed the rating of the diode. Temperatures should be compared to original test data and should not exceed 100ø C. </br>Recent evaluations have been unable to pinpoint a failure mode and there are no conclusive connections to previous failures. Only the failures provided in this report have surfaced for the subject part numbers and the failure rate has been low. </br>AMETEK SOLIDSTATE CONTROLS CORRECTIVE ACTION: AMETEK Solidstate Controls will work with you to arrange replacements and spare parts for your application as needed. Please contact our Client Services group at 1-800-222-9079 or 1- 614-846-7500, extension 1.</br>Notified R2DO (Miller) and the Part 21/50.55 Reactors E-mail group. 21/50.55 Reactors E-mail group.
Has query"Has query" is a predefined property that represents meta information (in form of a <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Subobject">subobject</a>) about individual queries and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
00:00:00, 11 February 2022 +
Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
20:02:51, 4 January 2024 +
17:20:00, 1 April 2021 +
0.555 d (13.33 hours, 0.0793 weeks, 0.0183 months) +
04:00:00, 1 April 2021 +
URL"URL" is a <a href="/Special:Types/URL" title="Special:Types/URL">type</a> and predefined property provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a> to represent URI/URL values.