Building and construction-electricity
A construction worker was fixing cladding to a wall with screws when one hit an electrical cable. When his mate touched the metal cladding he was electrocuted. The employer had not disconnected the power and had not checked for cabling.
The most common causes of electrocution in the building construction industry are:
- contact with overhead wires, usually when using equipment
- faulty electrical tools
- Working with or near equipment that people think is off or 'dead' but is actually on or 'live'
Electric shocks happen when a person becomes part of an electrical circuit and the current flows through their body.
Incidents with electricity are usually caused by a lack of experience, training or supervision, broken equipment or dangerous work conditions.
How can you keep safe?
- plan and discuss the job with your boss
- use the correct earthing equipment
- regularly check and clean the tools that you use
- switch off appliances at the power point before you pull out the plug. Electrical equipment can still partially operate without being plugged in due to stored energy. When you turn off the main power supply, just leave the equipment switched on for a while to release the stored energy
- limit damage to electrical cords by keeping them off the ground
- check the location of overhead wires and stand clear of any fallen power lines
- use equipment properly. Check instructions and follow them
- make sure you are supervised at all times by a qualified worker
- don't overload power boards with lots of electrical appliances
- report any breakdowns or faulty equipment to your boss
Your boss should provide residual current devices (RCDs) or safety switches on construction sites to reduce the risk of electric shock and electrocution.
What is a Residual Current Device?
That's safety switches to you and me. These RCDs, as they're known in the business, cut off the power if there is some sort of problem.
If you are using portable electrical equipment, power tools and extension lead at work it must have a RCD that is at a fixed switchboard or in a fixed power point. This is the law!
What happens when electrical equipment has to be serviced or repaired?
Electrical supply is disconnected first then
- locked
- isolated
- tagged
- tested
- checked
before any other work is done.
Lock
This is when a lock is put on an ON switch so the machine can’t be turned on. Only the person who put it on can remove it. If that person isn’t available, strict rules need to be followed to ensure it is removed safely.
There are a wide range of 'locks' that can be used in this process. These can be:
- Switches with a built-in lock
- Chains
- Jaws or hasps
There should be one key only for each lock held by the person who put it on. A master key is generally kept in a safe place. This reduces the risk of the lock being opened during repairs or cleaning.
Isolate
This means the electrical circuits must be shut down.
Tag
This means the proper safety tags need to be put on the machine.
Tie-on tags are not enough to isolate the electricity they are there to provide information to other workers about what’s happening with the equipment. Tags have information about the name of the person working on the equipment, the time and date of the work and the equipment that's being isolated.
Warning tags that are normally used are:
Personal danger tags
These are red, white and black and are put on equipment to warn people that the equipment is being worked on and must not be used.Out of service tags
These are yellow and black and used to warn people that equipment is damaged, unsafe or faulty and cannot be used until it is replaced or repaired.
Test
This means that all power sources need to be checked with the proper test instruments to make sure everything is right before going ahead with work.
Check
This checking test instruments before starting work.
Want to know more about electricity?