When working in the vicinity of exposed electrical equipment or on live electrical circuits, it is necessary to protect not only the equipment being worked on, but also the operator. To that end, insulated hand tools are essential components of proper personal protective equipment and should always be used in these cases to provide maximum operator protection.
First of all, we must not confuse the isolated tools with the conventional ones of very similar aspect provided with plastic coating or plastic handles, which do not have any type of protection to use in circuits with energy. Therefore, it is very important to make sure to use tools marked with the official international double triangle symbol, that have a maximum use rating of 1000V, have been dielectric tested to 10,000V and must also comply with IEC 60900. Even despite these ratings, many manufacturers of isolated tools Consider these as a secondary protectionTherefore, all electrical circuit operators should also use appropriate protective equipment together and observe established work safety practices.
In this article we are going to detail some considerations for the use and special care of the isolated tools that will surely be useful for those interested.
Who should use insulated tools?
Anyone working on or in the vicinity of exposed energized conductors or circuit parts where at least one hand tool is required. For example:
- Expert professionals: maintenance technicians for batteries or heating, ventilation and air conditioning (HVAC) systems.
- Electricians: commercial or industrial facilities.
- Utility workers: people in charge of reading home electricity consumption meters, operators of distribution boards or switch houses, operators of nuclear plants and substations.
- Workers in the area of renewable/clean energies: solar, wind and electric cars.
Some practical examples
To understand the above more clearly, let’s look at a few examples where thinking of a isolated tool It is not only recommended, but rather essential.
a) Use of tools
Case 1. Screwdriver: Suppose an electrician who is to secure a green screw for the ground wire inside a control panel slips the screw while applying his force to the screwdriver and direct phase-to-ground contact is established. In addition to producing an electric shock, the tools without insulation can compromise the discharge gap between energized conductors or circuit parts and lead to an electrical arc that causes skin burns, hearing loss, eye damage, and could even create an arc flash.
Case 2. Socket wrench: now imagine a specialized mechanic who is working on an electric/hybrid car, whose huge battery has a large amount of stored energy that simply cannot be deactivated. Tightening the battery connection with a socket wrench makes contact with the opposite terminal. We could argue that the socket wrench just needs a bit of electrical tape to fix the problem. But is it enough? Tools wrapped in electrical tape only provide an immediate sense of security, but there is no way to technically assess the voltage level associated with the so-called “insulation”. As soon as the tool bumped, dropped, or grabbed by a sharp edge, the insulation value of the insulating tape is nullified. The isolated tools they are designed to withstand some normal abuse, as most are double-coated and colored to let us know when to replace them.
Case 3. Pliers: An apprentice working in a dimly lit underground area cuts a dead cable on a cable management arm and makes one of the most common mistakes, which is cutting the wrong cable. could one tool special avoid this? The answer is yes, because among the insulated tools there are cable cutters provided with a ring at the cutting end, which only allows cutting the cable that is known in advance to be without power.
Case 4. Socket/socket wrench with straight handle: While on the job, a person reading a meter for a utility company finds a loose wire. What does the worker do to correct this? You can use an insulated straight-handle socket to get into a tight area and position the tool over the bolt head or nut to tighten that loose wire, without worrying about accidentally making contact with another phase or the meter base.
b) Particular situations
Case 1. Lockout/Tagout Operations: In environments where activities are carried out to build, install, configure, adjust, inspect, modify and/or maintain machines or electrical equipment, operators may be exposed to unexpected energy or release of dangerous energy. Therefore, whenever work needs to be done on them, equipment is first de-energized by lockout tagout operations (Lock Out & Tag Out, LO-TO), but are still close to other energized equipment. Under these conditions, an operator may accidentally lose control of the tool, which could make contact with live parts. If in this scenario you use manual tools In addition to an electric discharge, it is very possible that a phase overcurrent is generated and an electric arc is produced. Not only would the operator be exposed to injury, but equipment in the vicinity of this incident could be seriously damaged, leading to costly repairs, replacement, or downtime.
Answer to common questions
Now we are going to review a series of questions that many workers formulate when thinking about a isolated tool.
a) Can insulated tools be used on live circuits?
Insulated tools are designed to prevent shock in the event of an accident. The operators of these tools must always work with the circuits no electrical voltage Therefore, this is the first measure that should be taken. Once this security measure has been taken, the isolated tools so that if there is any fortuitous derivation, or someone connects the electrical voltage, an accident does not occur.
b) Can the tools lose their insulating protection?
Should the insulation be compromised, for example if the plastic coating cracks or scratches, exposing the conductive material it covers, in fact the tool will lose its insulating properties. While there are tests that can confirm the insulating qualities of each tool, some repeated testing can break the integrity of the insulation, accelerating the need to replace the tool. tool. This is why insulation designs often have two different colored layers to help the user identify cuts or damage to the outer layer when the inner layer is exposed. The effectiveness of this identification depends on the contrast between the two colors and the quality of the visual inspection that is carried out.
c) Are there requirements to periodically repeat the tests of isolated tools?
No, but in all parts of the world, occupational safety regulations state that protective equipment must be kept in a safe and reliable condition, and must be inspected or evaluated in accordance with various laws. Most manufacturers suggest the following precautions for isolated tools:
- Keep tools clean and dry.
- Examine the insulation before each use: If the integrity of the insulation is in doubt, destroy the tool or retest it.
- Follow the temperature recommendations for use indicated by the manufacturer.
- Have a qualified person annually inspect and recertify tools for safe use.
- Use other personal protective equipment and measures as needed.
d) What are the other safety equipment and measures to be used?
In the United States, for example, many contracting companies adhere to the NFPA 70E standard, which establishes the use of insulating gloves when working in the vicinity of energetic environments. However, the OSHA (Occupational Safety and Health Administration, USA) regulation clarifies that if they are used isolated tools It is not necessary to additionally wear protective gloves.
However, we have seen above that many manufacturers consider their isolated tools as “secondary protection only”, so they recommend the user to use gloves together with their tools. But that’s not all: many operators don’t realize that when entering an energized environment to perform maintenance or repairs, they must also remove all conductive items, such as cell phones, radios, metal-framed safety glasses, pens, and keys, either in your pocket or in the belt loops of your pants.
e) What to consider when buying an insulated tool?
Once we have decided on the design of isolated tool that we find more comfortable, we must consider some important details when acquiring it:
- brand and certificate: it is important that the isolated tool is correctly marked, and that it also has a certificate of conformity with the standard IEC60900.
- Choose a recognized brand: the overall quality of a isolated tool it cannot be judged solely by the method of isolation. The quality and performance of the base tool is critical. Brands that specialize exclusively in isolated tools they acquire their base product from various sources that the future user does not know about. On the other hand, tool manufacturers in general that enjoy local and/or international prestige use their own stock of tools, which provides confidence and security to the buyer. On the other hand, a well-known manufacturer can meet the needs of all kinds of isolated tool that is not necessarily included in its catalog, so, at the request of the client, it will be able to isolate the requested tool and offer it to the client in a custom design and/or size.
- check grip: Let’s choose an insulated tool that provides a secure grip, so as to reduce the possibility of falls or slips and therefore minimize the risk of personal injury.
- Compare warranties: All things being equal, a warranty (and its terms) can make a big difference between effectiveness and time lost on claims. That is why a trusted brand will offer us a permanent guarantee for our isolated tools.