Danger Isolate Main Supply Before Opening Safety Sign
Warns personnel to isolate the main electrical supply before opening equipment to prevent electric shock or injury
• Ensures electrical systems are safely isolated before access
• Ideal for plant rooms, electrical cabinets, maintenance areas, and industrial sites
• High-contrast yellow and black design for maximum visibility
• Available in durable materials suitable for long-term use
• Helps reduce risk of electrical accidents during servicing or inspection
Product Overview
This danger sign clearly instructs individuals to isolate the main electrical supply before opening equipment, helping to prevent serious injury or electric shock. Featuring a bold warning triangle with a lightning symbol and clear text, it is designed to communicate essential safety instructions in environments where electrical hazards are present.
Where to Use
- Electrical control panels
- Plant and boiler rooms
- Maintenance and service areas
- Industrial and commercial facilities
- Workshops and engineering environments
Key Features
- Clear "Danger" header with electrical hazard symbol
- Direct instruction to isolate main supply before opening
- High-visibility yellow and black colour scheme
- Easy-to-read text for quick understanding
- Supports safer maintenance and operational procedures
Materials & Options
- Rigid Plastic (1mm)
- Rigid Plastic (2mm)
- Self Adhesive Vinyl
Compliance
This sign supports compliance with UK health and safety regulations, including:
- Health and Safety at Work etc. Act 1974
- Safety Signs and Signals Regulations 1996
Frequently Asked Questions
Where should this sign be installed?
This sign should be installed directly on or near electrical panels, enclosures, or equipment that require isolation before access.
Is this sign suitable for outdoor use?
Yes, when produced in appropriate materials such as rigid plastic, it is suitable for both indoor and outdoor environments.
What does this sign indicate?
It indicates a serious electrical hazard and instructs users to disconnect the main power supply before opening equipment.
Trade Discounts
Rainbow Safety supplies safety signs to trade professionals across the UK.
Our trade customers include:
- Fire safety service companies
- Fire risk assessors and safety consultants
- Electrical wholesalers
- Facilities management companies
Approved trade customers receive:
- Preferential trade discounts
- Better margins for reselling safety signs
- Marketing support to help you sell more signs
- Access to our full range of safety signs
With the support and marketing tools provided, our sales have grown to over £3,000 per month.
Fire extinguisher servicing margins are not what they used to be, so supplying safety signs has become a valuable additional revenue stream for our business. On one warehouse safety survey alone we invoiced £5,100 on a single order.
We can now compete with internet prices and still make a healthy margin.
We were regularly asked to supply safety signs, but struggled to compete with internet prices while maintaining a worthwhile margin.
Working with Rainbow Safety has changed that. We can now offer our customers a competitive range of safety signs while still making a healthy margin for our business.
Loyalty Rewards
Rainbow Safety rewards regular customers across the UK who order safety signs on an ongoing basis.
- Schools and colleges
- Facilities management companies
- Contractors and maintenance teams
- Offices and commercial premises
- Preferential pricing for regular customers
- Free design service for custom safety signs
- Access to exclusive promotional offers
- Dedicated account manager if required
“Rainbow Safety has become our go-to supplier for safety signs.”
We regularly need safety signs for maintenance work, refurbishments and ongoing compliance updates. Since ordering from Rainbow Safety, the process has been straightforward, reliable and cost-effective.
The loyalty rewards and special offers have helped us save money across repeat orders, while the wide product range means we can usually source everything we need in one place.
Fast ordering, consistent quality and ongoing rewards have made Rainbow Safety a valuable supplier for our business.
Reviews
he sign does the job: clear message, good quality build, and easy to install — we used screws and it stuck to our electrical cabinet door just fine. That said, on a larger site or a busy workshop the standard size might get lost among other notices or equipment. For a small workshop or domestic install it’s fine; for larger facilities I’d consider a bigger version to improve visibility.
We installed this “Isolate Main Supply” sign at the main electrical panel in our workshop near Wellington, and it instantly raised awareness. The wording and hazard symbol are bold and unmistakable, so everyone knows to shut off power before opening the enclosure. The rigid‑plastic version we got feels sturdy and weather resistant — even when exposed to damp conditions or outdoor dust, it remains firmly fixed. A small investment for real peace of mind and better site safety compliance.
On our rental‑property site in Christchurch, we used this sign to mark the main supply isolation point before maintenance. It’s simple but effective — easy to read, professional layout, and complies with standard safety signage requirements. Attachment was straightforward (we drilled it onto the distribution board), and it has held up well without fading or loosening after a few weeks. Good safety practice — well worth having on site.
The sign is clear, the hazard symbol works well, and the instruction to isolate the main supply before opening is direct and useful. We placed ours on a metal distribution board — it adhered well and was clearly visible. My only small complaint: if you mount it on rough or uneven surfaces (like concrete or textured walls) the adhesive version may struggle to stay fixed; in that case a drilled/mounted sign is better. Still, good quality and helpful for safety compliance.