Maintenance zone: protect your workers while optimizing your operations!

Does your installation include multiple cranes on the same runway? If so, a maintenance area could be useful. Let’s see what it is…

First, what is a maintenance zone? It is a portion of the runway that can be reserved to safely perform maintenance work on your lifting equipment at a chosen time. With this solution, the section can be powered down (no more energy source) independently from the rest of the track, which is a major advantage. This way, a technician can service an overhead crane in this area without risking electrical injury (electric shock), while other lifting devices can continue to be used. In addition, by determining the correct length, this section will also be safe from collision. If the adjacent bridge attempts to enter this area, it will stop automatically due to being no longer electrically supplied. What should be considered when creating a safe maintenance area?

The first essential element is what is called the “buffer zone”. It’s an intermediate section between the energized zone and the unenergized zone. Why is it important? For two reasons.

A buffer zone for a true powered down zone

The primary purpose of having a buffer zone is to create a genuine powered down maintenance zone. To understand why, let’s look at how overhead cranes are electrified.

Electrical current is transmitted to the crane through energized power bars along their entire length. During the movement of the equipment, contact shoes attached to the bridge slide on the bar to collect the current. They are known as collectors. In theory, when these collectors arrive in the locked section, they will cease to be powered, and the device will come to a stop. But in fact, especially with the use of double collectors (two collectors that follow each other), the collector system could transmit the electric current to the locked area! How can that happen?

If half of the collector assembly has crossed the powered down line, the other half is still in the powered section. As electricity is constantly moving, the area that should be without current receives it through the part of the collector that is still energized (electric conduction). The section that was supposed to be without energy is therefore energized at this precise moment. It is then necessary to wait until all the contact shoes have passed from the powered down line so that the current dissipates and is no longer a danger. Hence the importance of the buffer zone. This small section between powered down zone and energy zone will serve as a transition to avoid electrical conduction. Without this critical section, a technician performing an intervention on an electrical component runs the risk of being electrified even if he is in the maintenance area.

The buffer zone allows the crane to stop completely

The second reason why a buffer zone is necessary is to allow the crane to stop completely. Indeed, if a crane crosses the maintenance area, it will eventually stop, as it is no longer energized. But it has accumulated kinetic energy (force of motion), which means that the crane will slow down gradually before coming to a complete stop. In order to determine the buffer zone’s length, we must consider the full-load deceleration of adjacent lifting equipment, otherwise a serious accident could occur.

To summarize, the buffer zone has two purposes: to guarantee a genuine unpowered zone in the maintenance section and to permit the complete stoppage of an approaching crane. In other words, if there is no buffer zone, the maintenance zone will not be safe unless temporary stops are used to physically prevent equipment from approaching it.

A clear display is essential

The second essential element to obtain a safe maintenance area is the display. Although it may sound simple, it should be made clear to maintenance technicians where this safe section is located. A clear display, such as signs on the track, should indicate the beginning and ending of the maintenance area.

Before getting started

What should be considered before implementing your isolation zone?

The first thing is, where should this area be located? Installing a maintenance zone at the ends of the runway will make the project less expensive. But if it meets the above requirements, it can be placed anywhere. What about the length? This will depend on the design, but also on the number of cranes you wish to allow in that zone at the same time. And finally, it will be necessary to evaluate the type of power bars already in place. Although it is possible to install this system on existing bars, it is not excluded that a complete replacement is necessary, especially if the current bars are old.

The above clearly demonstrates how important it is to collaborate with professionals to implement such a system. There are significant security issues associated with that kind of project. Lifting experts, such as the Premium Industrial Group, can help you develop your solution.

Benefits

A maintenance zone can increase productivity, since servicing your critical equipment can be performed during active hours without stopping your entire production line. This solution saves money due to the higher cost of out-of-hours interventions. Not to mention that the technicians are naturally more accessible during working hours, which adds to the flexibility. All the above leads to financial benefits.

Another interesting advantage: secure an area to perform various works at height. You may sometimes want to use the runway space for other types of work than crane maintenance. The maintenance zone makes it possible to work safely, using a lifeline for example.

And finally, what about the impact on occupational health and safety! Indeed, the maintenance area is a solution that makes security much faster and much easier. This prevents people from bypassing security rules to go faster.

Want to keep your workers safe and productive? The service area is an excellent option and is part of the world of solutions offered by Premium.