AWB 24-3 Issue 1 - Mechanical products 3 phase circuit breaker - incorrect marking
AWB 24-3 Issue 1, 11 January 2002
Mechanical products 3 phase circuit breaker - incorrect marking
Mechanical Products 3 phase circuit breaker (C/B) Series 4330.
From the CASA SDR system CASA has been advised of a non-conforming circuit breaker.
The C/B manufactured by Mechanical Products Inc is from their 4330 series. Subsequent investigation by the supplier of this item revealed a number of similar anomalies over a range of these products.
The faulty C/B's were found included as part of service bulletin kit supplied by Bombardier. Bombardier is producing formal notification to operators of their aircraft to inspect the circuit breakers prior to use and to inspect those in service.
CASA is currently waiting for a formal response from the FAA and the C/B manufacturer, however Mechanical Products have confirmed the problem. A subsequent check of manufacturing procedures and stock have not revealed further problems.
Description of defect
The faulty C/B had the phasing identifications interposed on the line and load sides of the C/B
Product and date code identification:
On the side of the breaker stamped with the part number you will find the date code, it is printed immediately after the "U.S. Government Cage Code" 76374.
The first two digits are the year of manufacturer, the second two digits are the week of manufacturer. So "0046" indicates the breaker was manufactured in the year 2000, in week forty-six. The faulty products of which Mechanical Products is aware of are limited to week 46.
- CASA recommends that all aircraft operators and Certificate of Registration holders, ensure that a review is conducted of all stock of Mechanical Products C/B's Part Number 4330-001-X where X = the current rating, purchased replaced since the third quarter 2000.
- CASA recommends that all Aircraft operators and Certificate of Registration holders review maintenance records and/or carry out a physical inspection of all C/B's of this series part number replaced since the third quarter 2000.
- CASA requires that any defective C/B's be reported to CASA via the SDR system. On line access to the report is available from the CASA web site http://casa.gov.au/airworth/sdr/index.htm
Disposition of faulty items
Mechanical Products have advised that faulty items may be returned to them and be covered under warranty which is limited to product replacement only, Mechanical Products issue an RMA # the product is returned to them, they inspect, verify problem and then issue a no cost replacement part. Alternately contact the supplier from where you purchased the item.
CASA will update this bulletin as information is received from Mechanical Products and the FAA.