Adding an overhead crane to an existing structure: As simple as checking the capacity?
The capacity of my structure allows me to add a new crane! Is it that simple?
Growth is a goal that spans industries. As companies expand over time, they must increase production accordingly. When client demand increases and production must follow, additional facilities and equipment are often required to meet new client needs. This principle also applies to overhead cranes.
When it is time to add lifting equipment to an existing crane runway, the logic is often: “I have a structure with a ten-ton overhead crane. With this structure’s capacity, it won’t be a problem to add a new ten-ton crane to this crane runway.” But is this actually the case? Are there other issues to consider before adding a new lifting device to a structure that already has one? The answer to these questions is important if you are a growing company.
Let’s take a look at the three key factors to consider.
1. Structure Capacity
The structure’s capacity is the first factor in determining if new overhead cranes can be added. There are three possibilities: the new equipment can have a capacity that is less than, equal to or greater than the capacity of the structure.
But this is not the only load-related factor that needs to be analyzed. Spacing between the cranes must also be taken into account.
New crane with equal or less capacity
Plan or engineering
The first step is to check the structure’s engineering plans, where the capacity is established. Even if finding the plans requires a little digging or asking the entrepreneur, the valuable information in these documents is essential. For example, do the plans provide for the future addition of a crane? If yes, do the specifications of the new overhead crane correspond to the specifications in the structural plans? Confirm this information to move on to the next key factor.
Specifications and spacing
Even if the capacity of the new equipment is equal to or less than that of the structure, there are still further considerations before installing a new overhead crane. Often, the plan contains a table of specifications indicating the factors that must be taken into account for an addition (see the following table as an example). This table may specify that a single overhead crane is permitted on the structure. But in other cases, the table indicates that lifting equipment can be added with the proper spacing. This spacing, which is determined by the engineer, must then be planned and maintained at all times using mechanical or electric spacing systems (mechanical extension, laser system, etc.). This may impact the positioning of the lifting devices and, consequently, acquisition-related decisions.
New overhead crane with a higher capacity
Unless the addition of a higher-capacity overhead crane has been stipulated in the original plan, only a full analysis by an engineer can establish if the structure can support the load of this new device. It is therefore likely that this process will reveal the need to reinforce the structure (for reference: https://structuresindustriellespremium.com/en/services/crane-runway-reinforcement/) or make other modifications to be able to add an overhead crane.
2. The Conductor Bar System
The second, less obvious, key factor is the electric system made up of conductor bars. This system was designed for the existing system but is not necessarily appropriate for the combination of several pieces of equipment. Let’s take a closer look.
The crane runway conductor bar model was selected based on the amperage required for the equipment currently in place. But will this electrical capacity be sufficient for a new crane? If this capacity is not taken into account, electrical problems may arise. For example, motors may overheat and be damaged. The conductor bar manufacturer can provide the capacity and amperage of the new equipment’s various motors. This data and appropriate calculations can be used to ensure that the bars are adapted to the new configuration. Otherwise, they must be replaced by a system with a higher rating.
All electrical power systems experience calculated voltage drops. But again, the acceptable variation for a single crane might not be acceptable if a second piece of equipment is powered by the same system. This voltage drop must therefore be mitigated to avoid other problems.
Sometimes, the solution consists in adding an additional feed point on the bars. In other cases, the best option might be to install a parallel system, such as adding new bars on the opposite crane runway.
3. Power Supply Isolator
An overhead crane’s electrical system has its own breaker to cut the power as needed. Here again, this breaker is designed based on the current installation and does not take into account future additional equipment. This is the third key factor to consider.
The breaker is designed based on the amperage of the electrical system in place. This means that the rating of the fuses and electrical cables is directly related to this power. If the amperage of the crane runway is increased by adding a new crane, the fuses of the breaker or electrical cables might no longer be appropriate and must be replaced. This modification might have an effect on the electrical panel of the breaker itself, which might no longer have physical space to accommodate these modifications.
The isolator therefore must be checked before proceeding. Per the standards in force, only master electricians are authorized to make any necessary adjustments.
Trust the Experts
Consult a lifting specialist before adding lifting devices to a crane runway. It is not as straightforward as it seems, and they are best positioned to assist you. Why?
Overhead crane manufacturers provide the capacity data to engineers for calculation purposes. They also check and assess the sufficient electrical capacity of the conductor bar system as well as voltage drops. All this makes them true lifting experts!
Premium Industrial Group has all the tools you need to get your project off the ground. It can assist the various stakeholders to ensure that loads will meet the structure’s design criteria. It knows how to calculate the amperage required for multiple pieces of equipment, the acceptable voltage drop as well as the cost of materials for the various modifications. It knows suppliers for components, including conductor bar systems. Although overhead crane specialists are not authorized to modify isolators (master electricians only), Premium can provide an estimate of the electrical loads for the master electrician’s assessment. Furthermore, with its partnership with Premium Industrial Structures, your structure analysis or reinforcement can be addressed as part of a turnkey solution at the same time as your new overhead cranes. Premium Group has got you covered on every angle of your growth!
When adding lifting systems, it is always better to be certain than to assume. Put your growth in expert hands to ensure success!