• About
  • Log on
  • Register
  • Contact
  • Home
  • Safety Resources
    • Incident Alerts
    • HiPos Report
    • Guidance
    • Good practice
    • Toolbox talks
    • Hot Topics
    • Other resources
    • Videos
    • Safequarry App
  • The Fatal 6
    • Overview
    • 1. Contact with moving machinery and isolation
    • 2. Workplace transport and pedestrian interface
    • 3. Work at height
    • 4. Workplace Respirable Crystalline Silica
    • 5. Struck by moving or falling object
    • 6. Road traffic accidents
  • Vision Zero
    • Overview
    • Employee Guide
    • Core Values
    • Fatal 6
  • Safer By
    • Overview
    • Safer by competence
    • Safer by association
    • Safer by design
    • Safer by partnership
    • Safer by sharing
    • Safer by Leadership
  • Public Safety
    • Summary
    • Stay Safe
    • Cycle Safe
  • Health & Wellbeing
    • Quarries Partnership - Dust
    • Mental Health & Wellbeing
    • COVID - Safer by Sharing
    • COVID MPA Resources
  • Awards
    • Enter
    • Event
    • Sponsorship
    • Guides
    • Videos
    • Entries
  • News
  • My Information
    • My Saved Files
    • My CPD Report
  • Home
  • Safety Resources
    • Incident Alerts
    • HiPos Report
    • Guidance
    • Good practice
    • Toolbox talks
    • Hot Topics
    • Other resources
    • Videos
    • Safequarry App
  • The Fatal 6
    • Overview
    • 1. Contact with moving machinery and isolation
    • 2. Workplace transport and pedestrian interface
    • 3. Work at height
    • 4. Workplace Respirable Crystalline Silica
    • 5. Struck by moving or falling object
    • 6. Road traffic accidents
  • Vision Zero
    • Overview
    • Employee Guide
    • Core Values
    • Fatal 6
  • Safer By
    • Overview
    • Safer by competence
    • Safer by association
    • Safer by design
    • Safer by partnership
    • Safer by sharing
    • Safer by Leadership
  • Public Safety
    • Summary
    • Stay Safe
    • Cycle Safe
  • Health & Wellbeing
    • Quarries Partnership - Dust
    • Mental Health & Wellbeing
    • COVID - Safer by Sharing
    • COVID MPA Resources
  • Awards
    • Enter
    • Event
    • Sponsorship
    • Guides
    • Videos
    • Entries
  • News
  • My Information
    • My Saved Files
    • My CPD Report

The Health and Safety Hub for the Mineral Products Industry - aggregates, asphalt, cement, concrete, contracting, dimension stone, lime, precast concrete, masonry, mortar, readymix, recycling, silica sand, transport & logistics

  1. Home
  2. IncidentReports
  3. IncidentView

Faulty Isolator Handle

LOCATION:
QUARRY
ACTIVITY:
MAINTENANCE & HOUSEKEEPING
SUB ACTIVITY:
N/A
ALERT STATUS:
Normal
DATE ISSUED:
12/08/2011
INCIDENT No:
00295

TITLE
Faulty Isolator Handle
COUNTRY OF ORIGIN

WHAT HAPPENED

The Log-Washer at a Sand and Gravel Quarry stopped working. It appeared that a fuse had blown within the panel in the switchroom.

The manager turned off the isolator handle on the Fuse Combination Unit (FCU), (A typical FCU is shown in Photo No 1 below) this released the mechanical interlock allowing the cabinet to open.

Prior to removing the fuse the manager used a volt meter to check that isolation had indeed taken place and to his horror found that a high voltage still existed across two out of the three fuses and between these two phases and earth.

Had anybody touched the fuses or other conductors within the panel by hand or with a tool at this point it would have resulted in electrocution.
Arrangements were made for an electrical contractor to replace the FCU.

On opening the ‘failed’ FCU it was found that the rocker ‘cam’ had sheared on two of the three phases leaving the incoming sliding contact in the closed position bridging the contact terminals allowing power to flow through the fuses

There were no physical indications on the FCU to suggest that there was a problem of this magnitude.
ACCIDENT / INCIDENT IMAGES
Click image to enlarge

Example of FCU


LEARNING POINTS / ACTIONS TAKEN

The FCU was replaced by a competent electrical contractor.

The Lock-Off and Isolation Procedures throughout the company must be amended to include testing every time that access is required inside a panel (to, for example, replace fuses or reset trips): to ensure that all parts to be handled are de-energised. The isolator handle cannot always be trusted to do this.

The foregoing applies to all aspects of business, not just Quarries.

The outcome in this incident could have been very different had the manager not carried out testing before attempting to remove fuses.
LEARNING POINTS / ACTIONS IMAGES


LOCATION:
QUARRY
ACTIVITY:
MAINTENANCE & HOUSEKEEPING
SUB ACTIVITY:
N/A
ALERT STATUS:
Normal
DATE ISSUED:
12/08/2011
INCIDENT No:
00295


Request Futher Information
Print Page
convert this page to a pdf
Go Back to Search Critera

About
Mineral Products Association, 1st Floor, 297 Euston Road, London NW1 3AD
Tel: 0203 978 3400
Email: info@mineralproducts.org
MPA Logo
Contact
  • Privacy
  • Developed by OFEC
↑