FM Approvals has been made aware by Mettler-Toledo, LLC that the Models 30538111 and 64060625 Intrinsically Safe Battery Packs are capable of developing a surface temperature in excess of their marked Temperature Classification for potentially explosive gases and vapors and their temperature rating for potentially explosive dusts.

Company Identity:  Mettler-Toledo GmbH

Address:  c/o Mettler-Toledo LLC, 1150 Dearborn Drive, Worthington, OH 43085

Contact Information:  Tel: 1-800-786-0040  Email: INDsupport.am@mt.com

Product Identity: NiMH Rechargeable Battery Packs

Make/Model:  30538111 & 64060625

FM Approval Status:  FM Approved in US & Canada, ATEX & IECEx.

Approval Certificates Summary

Model 30538111:  FM19US0232, FM19CA0125, FM19ATEX0216, IECEx FMG19.0046

Model 64060625:  FM19US0149, FM19CA0079, FM FM07ATEX0043, IECEx FMG12.0026

Hazard Involved:  The products in question are battery pack power supplies and bear the labeling indicating they are certified for use in hazardous locations, with a temperature classification of T5, and a temperature rating for dusts of T93ºC. It has been determined that under a short-circuit condition, the packs are capable of developing a maximum surface temperature of 111ºC, which exceeds the marked ratings.

This issue is not considered to constitute a critical safety hazard, since the battery packs are intended for use with Mettler-Toledo Types MT IND226x, IND560x, and IND256x Intrinsically Safe weigh terminals, each of which have a temperature classification of T4. Since the packs are fitted with lead of maximum length 10 feet, they are very unlikely to be installed in a hazardous location with a Temperature Class requirement of T5. In addition, the surface exhibiting the temperature is situated such that it will not allow an accumulation of dust when mounted as intended, and the temperature developed is well below that which would normally be considered a concern for installation in dust environments.