Reduce the risk of system migrations

An integrator experienced in quick wiring adaptor tools can provide time- and cost-savings, and thus reduce downtime and risk.

By Frank Prendergast, Schneider Electric December 1, 2009


Photos depict a stepped process of migrating from a legacy I/O module to a new I/O module. (The legacy module in this case is the Schneider Electric SY/Max I/O; the new module is the Schneider Electric Quantom I/O.)

step 1 – Observe all safety rules and turn off all power sources to the rack and legacy I/O modules. Remove all electrical power from the rack and all non-I/O modules.

Step 2 – Remove all terminal blocks from legacy I/O modules.

Step 3 – Remove all legacy I/O modules from the rack, and then the rack itself.

Step 4 – Install the adapter plate kit, which allows installation of the new I/O modules’ backplane without having to drill into the enclosure subpanel.

Step 5 – Install the new I/O modules in the same location as the legacy I/O modules.

Step 6 – Install the quick wiring adapter terminal block into the new I/O module, then open the cover to the quick wiring adapter.

Step 7 – Insert the legacy terminal block into the quick wiring adapter, and close the cover. The system is now ready for startup.

Industrial facility managers understand the need for progress. Continually updating programmable logic control (PLC) systems can help facilities be more efficient, accommodate evolving needs, and better meet customer requests and deadlines. But an upgrade project is also one fraught with risk when it gets underway, and even after it is complete.

One of the main reasons is downtime. When it comes to a project like migrating a PLC system to newer, more robust components, facility managers envision an extensive period of planned downtime, often while a system integrator completes the job of component change-outs and rewiring. But also looming are concerns about unplanned downtime after the project is complete.

Accommodating for associated downtime requires meticulous planning and facility-wide cooperation. Facility managers typically plan ahead by increasing stock and production levels or re-routing processes. Another way to mitigate the risk of migration-related downtime is to carefully choose your system integrator.

Facility managers can avoid problems in both the short- and long-term by doing their homework. That means taking the time to extensively qualify system integrators with regard to the individual tools and industry partnerships they use. Such support plays a large role in quickly and efficiently completing system migration project and ensuring no unplanned downtime afterwards. An integrator with extensive experience with solutions like quick wiring adaptor tools, for example, can allow re-use of the original wiring for a new I/O module.

Rewiring needs and planning can be a major contributor to scheduled downtime associated with system migration projects, and related costs. Traditionally, transitioning between old and new I/O modules requires a significant amount of time to be spent on rewiring. On average, it takes approximately six hours to rewire a single rack. For systems with numerous racks, that time can quickly accumulate to weeks.

Additionally, extensive rewiring increases the chance for safety hazards and mistakes. During a complicated rewiring process, a single error by an integrator can result in extensive troubleshooting later to locate the problem. Other negative impacts of incorrect manual rewiring include system failure and even unintended equipment operation, which poses a real safety risk for anyone near a piece of equipment when it activates.

But rewiring is only half the battle. After rewiring is finished and operator training, re-commissioning and system start-up is completed, a product installation error can create a lengthy period of downtime to correct, compounding stress and increasing time and cost investments.

Migration tools lessen risk

The system migration process can be more efficient and less daunting when integrators use migration tools. Many control system manufacturers, for example, offer quick wiring adaptor tools for easy transition from existing I/O modules to new and more robust counterparts. Many I/O modules include prewired cables, so instead of being forced to remove and reterminate the wire, the terminal block is instead removed and connected to another prewired cable assembly (i.e., the quick wiring adaptor), and then connected to the system.

Here’s how it works in practice. After turning off all power sources to a rack, integrators simply remove all existing I/O terminal blocks from their I/O modules, and then remove the modules themselves. Then they install the new I/O modules in the same locations as the existing versions, followed by the quick wiring adaptor terminal block. With those components installed, integrators can install the quick wiring adaptor terminal block into the new I/O module. All that’s left is to open the cover of the quick wiring adaptor, insert the legacy I/O terminal block, and close the cover.

Verification processes done offline

By utilizing quick wiring adaptors, system integrators can complete a system migration project more efficiently. The wiring and verification processes are done offline, so integrators can do much of the migration with minimized system disruption.

Other steps typically taken during traditional system migration processes are eliminated with quick wiring adaptors, including system verification, re-commissioning and documentation. Since quick wiring adaptors are prewired and outfitted to quickly and efficiently transfer system platforms, the manufacturer of quick wiring adaptors typically provide a pre-validated wiring diagram that ensures reliable operation.

It’s estimated that technicians can transfer an I/O module rack in only one hour with quick wiring adaptors, compared to six hours through manual rewiring. When dealing with systems that include numerous racks, the compounded time savings is substantial.

Beginning the process

For facility managers researching and planning a PLC system migration, quick wiring adaptors offer a more efficient solution. As a first step to such a project, facility managers should research system integrators, meet with them in person, provide a tour of their operation and take the time to ask all necessary questions in order to be as informed as possible about their capabilities. Integrators should have extensive experience upgrading similar systems for other facilities and be aware of quick wiring adaptors.

Additionally, project managers should explore the cost and time investment related to both traditional system migration (i.e., including rewiring) and migration done with quick wiring adaptors. If the system is large and complex, quick wiring adaptors may be the most cost- and time-efficient option. However, smaller, less-complex systems may be just as easily handled through manual rewiring.

As facility managers continue to balance innovation and technological advances in their facilities, time, cost and associated risks weigh heavily on decision-making. Through devices like quick wiring adaptors and the expertise of system integrators that are experienced in their use, facility managers can complete a system migration project with limited downtime, increased safety and, ultimately, reduced risk.

For a list of 966 integrators experienced with panel wiring, search for "control panels" under "engineering specialties" in the Automation Integrator Guide at .


Author Information

Frank Prendergast is business development manager for Services and Industrial Solutions for Schneider Electric North American Operating Division. He has 20 years of engineering experience, including eight years as a chemical process engineer. His time at Schneider Electric has been focused in the services area, including customer system migrations.

CEtv videos showcase other panel building strategies

The winner of Control Engineering ’s Control Panel Video Tutorial contest showcased other ways to streamline wiring tasks. The control panel on CP Packaging’s VisionPak Horizontal Form-Fill-Seal Vacuum packaging machine was designed to save build-out and installation time, making assembly possible in hours rather than days. Servo drives, for example, were removed from the cabinet and distributed onto the machine — a change that saved about 60% in control cabinet space and 30% in wiring costs. The enclosure design, which includes high voltage and control components, includes terminal blocks that connect using insulation displacement technology to save time and keep the integrity of the landing points (to avoid shorting). Also, Rexroth integrated motors and drives are connected by one cable, instead of the previously required 12. To see CP Packaging’s winning video, click the Video tab on to access all CEtv videos, then click the “Control Panel Contest” tab.