It’s the final hour of Factory Acceptance Testing (FAT). The machine runs perfectly, until a VFD on an adjacent line spins up. Suddenly, the main servo jitters, and the vision system drops a packet.
The team spends the next four hours hunting for the problem, only to find a shield pigtail stuffed into a standard gland, turning the entire cable into an antenna. One 60-second check in the workshop could have saved a full day of on-site rework.
For machine builders, most FAT/SAT (Site Acceptance Testing) delays aren’t caused by the machine’s core design. As industry bodies like the International Society of Automation (ISA) explain, these tests are rigorous validation processes.
Failures are often caused by small, overlooked connectivity issues like poor grounding, incorrect routing, or inconsistent labelling. These “small fires” waste a commissioning engineer’s valuable time. This 12-point walk-through serves as a practical, habit-driven guide for locking in reliability before the machine ever leaves the workshop.
The 4-Phase Commissioning Walk-through
These 12 essential checks are grouped into four logical phases. This isn’t just a list; it’s a repeatable system for building a reliable, site-ready machine.
Phase 1: The Physical Foundation (Routing & Protection)
This phase ensures the machine is physically robust and that cables are protected from the machine itself (motion, heat, and vibration).
- Gland Selection & IP Integrity: This check focuses on whether the glands are the correct size, material, and IP rating for the environment. An ill-fitting gland won’t seal, inviting oil, dust, or moisture and potentially damaging the cable’s internals.
- Bend Radius & Routing: This area addresses the cable’s physical path. Key considerations include routing cables according to their minimum bend radius and separating power and signal cables to prevent noise. Cables should not be pulled tight against sharp edges or cinched by zip ties.
- Chain Loading & Travel: For power chains, this involves checking that cables are laid flat with separators, not over-packed. Cables must move freely without twisting. Proper strain relief at both ends ensures the connection point never takes the force.
- Sensor/Actuator Runs: This point covers sensitive analogue or sensor cables, focusing on their physical separation from “noisy” power lines. It also includes checking that any spare cores in a multi-core cable are properly terminated.
This phase is often simplified by moving work off the floor. Using pre-harnessed power chains from a solution like ÖLFLEX® CONNECT ensures every cable is cut, routed, and tested before it reaches the machine frame.
Phase 2: The “EMC-Clean” System (Noise & Grounding)
This phase is about eliminating the “ghost errors” and “mystery dropouts” caused by electromagnetic interference (EMI). A clean EMC system is a planned system.
- Shield Termination (360°): This critical check focuses on how shielded cables are terminated. A 360°, low-impedance connection to ground is the goal. Pigtails are generally not an acceptable solution, as they can act as an antenna and worsen EMI.
- Grounding & Bonding: This check verifies the machine’s grounding system integrity. It includes confirming all bonding straps are installed, paint is removed from grounding points, and continuity is verified. A solid ground path is essential for dissipating electrical noise.
- VFD & Power Zones: This area concerns high-noise VFD output cables. Best practice is to route them in their own metal conduit or tray, far from control signals. EMC cable glands like the SKINTOP® MS-M BRUSH are a common solution, providing a fast, repeatable 360° connection.
Phase 3: The Data & Logic Layer (Comms & ID)
This phase verifies the machine’s “nervous system.” A machine that can’t communicate reliably is a machine that won’t be accepted.
- Connector Interfaces: This check ensures all industrial connectors (e.g., M12, RJ45, circular) are from the agreed-upon family. It also involves verifying they are all correctly keyed, oriented, and locked. A loose connector is a future intermittent fault.
- Label & ID Scheme: This point addresses documentation. Do all cable and port labels exactly match the electrical and network drawings? Are device IDs (like IO-Link or IP addresses) correct and documented? Mismatched labels are a significant problem for service teams.
- Industrial Ethernet Health: This involves verifying that all Industrial Ethernet cables are running at their designed speed (e.g., 1 Gbit/s, Full-Duplex). A device forced to 100 Mbit/s could indicate a bad patch cable or termination.
Phase 4: The Handover Pack (Docs & Spares)
This phase ensures the machine arrives at SAT with a complete “kit” for success, making SAT a simple validation, not a process of discovery.
- The Complete Documentation Pack: This step is about the “as-built” documentation. This should include the final frozen Bill of Materials (BoM), the cable schedule, network maps, routing photos, and a torque table for all glands and connectors.
- The “Day One” Spares Kit: A pre-packaged spares kit, ready to ship with the machine, is a key part of the handover. This typically includes pre-cut patch leads, spare glands, and critical pre-assembled cables, turning a potential day of downtime into a 10-minute swap.
The Bottom Line: Reducing Wasted Time On-Site
Passing FAT/SAT the first time isn’t about luck. It’s about discipline and treating connectivity as a core part of the design, not an afterthought.
By verifying the build with this 12-point guide, machine builders shift the risk away from the customer’s site and back into their controlled workshop. This process helps machine builders:
- Stop hunting for “ghost errors.”
- Reduce costly on-site commissioning time.
- Ship reliable, profitable machines on schedule.
Frequently Asked Questions (FAQ)
What if my team is used to their own parts and brands? The biggest reliability gains often come from a matched system where the cable, gland, and connector are designed to work together. Standardising on a single system (like ÖLFLEX® power, ETHERLINE® data, and SKINTOP® glands) can simplify the BoM, reduce inventory, and make troubleshooting predictable.
Is this methodology too much for a simple machine? This methodology is designed to simplify the build. A simple machine with one “pigtail” ground can still fail FAT due to EMI. These 12 checks are habits that scale. The same discipline can be applied to a small conveyor as to a complex robotic cell.
What are the benefits of pre-harnessing? Moving work off the workshop floor and into a controlled harnessing environment (like ÖLFLEX® CONNECT) is a direct swap of chaotic, error-prone labour for a clean, tested, plug-and-play module. It’s one of the fastest ways to make a FAT process repeatable and an SAT process faster.