Toolbox talk · Electrical · about 5 minutes
Why we use 110V on site
Download the PDF with attendance sheet
Why it matters
Construction sites use 110V centre-tapped to earth (CTE) for portable tools and lighting. If something goes wrong, a shock is far less dangerous than from 230V.
The hazards
- Using 230V tools on site without approval
- Damaged leads and plugs
- Overloaded transformers
- Missing or bypassed protection
Stay safe
- Use 110V tools and lighting on site, supplied from a Site Transformer
- With 110V CTE the most you can get from one live conductor to earth is 55V on single-phase, or about 63.5V on three-phase
- Yellow plugs and sockets are 110V; blue is 230V; red is 400V/415V
- Don't mix up connectors or use adaptors to get round them
- Where 230V is unavoidable, it must have RCD protection and the site's approval
- Don't overload transformers or outlets
- Check leads and plugs before use
Ask the team
- Why is 110V safer than 230V?
- What colour is a 110V plug?
- What would you do if you found a damaged transformer?
The law and guidance
Electricity at Work Regulations 1989. HSE HSG141, Electrical safety on construction sites.
General guidance to help you give a toolbox talk. It doesn't replace your site's risk assessments, method statements, permits or training. Check it against your own site rules before you give it.
