Machine Commissioning Checklist: 12 Connectivity Checks Before FAT/SAT

Factory Acceptance Tests (FAT) and Site Acceptance Tests (SAT) are the final gates before machine delivery. Connectivity failures at these stages delay handover and damage client confidence. A systematic pre-test inspection of cables, connectors, cable glands and labelling prevents the most common rejection causes.

What connectivity checks should you do before FAT?

Before FAT or SAT, verify all cable terminations are torqued to specification, cable glands achieve their rated IP protection, EMC shielding continuity is maintained through connectors and every cable is labelled per DIN EN 60204-1 requirements. A 12-point connectivity checklist covering power circuits, control signals, safety circuits and Ethernet/fieldbus connections prevents the most common commissioning failures. A structured checklist catches issues that ad-hoc inspections routinely miss.

Commissioning engineers often treat connectivity as secondary to functional testing. This creates problems: loose terminals cause voltage drops, unlabelled cables delay troubleshooting, incorrect cable gland installation compromises IP ratings and broken shield continuity leads to EMC non-compliance. These issues appear during acceptance testing when fixing them is expensive.

The solution is a pre-test connectivity audit that treats cables, connectors, glands and labels as a system. LAPP’s cable and connector portfolio (ÖLFLEX® cables, EPIC® connectors, SKINTOP® cable glands, FLEXIMARK® labelling) is designed for this approach. Each component references the others: cables specify compatible glands, connectors list approved cable types, labels match terminal block layouts.

How do you verify cable labelling meets DIN EN 60204-1?

DIN EN 60204-1 (IEC 60204-1) requires every conductor to be identifiable at both ends with clear, permanent marking. Verification involves three checks: labels match electrical drawings exactly, protective conductor (PE) is marked yellow-green or labelled PE and labels remain legible after environmental exposure. Use FLEXIMARK® marking systems with pre-printed tags or thermal transfer printers for industrial-grade durability.

Machine builders often discover labelling non-compliance during FAT when inspectors cross-reference cables against drawings. Missing labels, faded ink or incorrect designations trigger rejection. The standard requires labels at connection points, not just mid-span and mandates specific colour codes for safety circuits.

LAPP’s eshop marking systems offer compliant solutions: terminal markers that snap onto DIN rail blocks, cable markers with UV-resistant printing and heat-shrink sleeves with permanent text. For large installations, LAPP SEA’s harnessing service includes pre-labelled cable assemblies with QR codes linking to test certificates.

The 12-point connectivity commissioning checklist

This checklist assumes the machine is wired and ready for functional testing. Work through it 24-48 hours before scheduled FAT or SAT. Allow 2-4 hours for a typical industrial machine with 50-200 connection points.

1. Cable termination torque. Use a calibrated torque screwdriver to verify every power and control terminal meets manufacturer specifications. Record values in the commissioning log. Under-torqued terminals cause intermittent faults; over-torqued terminals damage conductor strands.

2. Cable gland installation. Check every SKINTOP® or equivalent gland achieves the specified IP rating. Confirm the seal compresses the cable sheath (not the individual conductors), the locknut is tight and the thread engagement meets minimum requirements. Pull-test each cable with 50N force.

3. EMC shielding continuity. Measure DC resistance from shield to ground at both ends of every screened cable. Resistance should be below 0.1Ω. Verify EPIC® connectors with 360° shielding maintain continuity through the housing. Broken shields cause radiated emissions failures and susceptibility to interference.

4. Protective conductor continuity. Test PE resistance from any exposed metal part to the main earthing point. IEC 60204-1 requires resistance below 0.1Ω for fixed equipment. Document results for every safety circuit.

5. Cable routing and bend radius. Inspect cable runs for compliance with minimum bend radius (typically 6-12× cable diameter for ÖLFLEX® types). Check for sharp edges, hot surfaces and moving parts that could damage insulation. Verify cable ties are not over-tightened.

6. Connector locking mechanisms. Confirm every EPIC® connector and similar multipin unit has its locking lever or screw fully engaged. Push-pull connectors should audibly click. Loose connectors cause intermittent signals that are difficult to diagnose.

7. Cable labelling at both ends. Cross-reference every cable label against electrical drawings. Verify labels are present at the panel end and the device end. Check PE conductors have yellow-green identification. Use FLEXIMARK® labels sized for the conductor cross-section.

8. Power circuit phase sequence. Measure phase rotation at motor connection points using a phase sequence indicator. Incorrect rotation damages equipment and violates safety standards. Mark correct phases L1, L2, L3 per IEC 60446 colour codes (brown, black, grey).

9. Safety circuit continuity and isolation. Test emergency stop circuits, safety relays and interlock switches for correct operation. Verify safety functions cannot be bypassed. Measure isolation resistance between circuits rated for different voltages (minimum 1MΩ at 500V DC test voltage per IEC 60204-1).

10. Fieldbus and Ethernet cabling. Use a cable certifier to verify Cat5e/Cat6 Ethernet cables meet transmission parameters (attenuation, NEXT, return loss). For PROFINET, EtherCAT or EtherNet/IP installations, confirm ÖLFLEX® industrial Ethernet cables are used, not office-grade patch cables. Check connector boot strain relief.

11. Cable entry seals and blanking plugs. Inspect every unused cable entry for a properly installed blanking plug maintaining the panel’s IP rating. Verify cable entries have the correct gland size (no oversized holes with adapter plates). Check gasket condition on enclosure doors.

12. Documentation package completeness. Assemble cable schedules, termination records, test certificates and as-built drawings. Include LAPP product datasheets for cables and connectors used. Prepare a deviation list if any specification changes occurred during build. This package is required for SAT sign-off.

After completing the checklist, photograph critical connection points for the commissioning record. These images prove compliance if questions arise during acceptance testing or warranty claims.

What documentation do you need for SAT?

SAT sign-off requires a documentation package covering five areas: as-built electrical drawings reflecting any changes from design, cable schedules with manufacturer part numbers and installation locations, test records for insulation resistance and protective conductor continuity, certificates of conformity for specified standards (such as LAPP certification documents), and a completed commissioning checklist.

This package demonstrates machinery directive compliance and forms the basis for operator training and maintenance procedures.

Many machine builders underestimate SAT documentation requirements. Inspectors expect traceability from specification through procurement to installation. Missing test records or incomplete cable schedules delay acceptance even when the machine functions correctly.

Organize documentation by system: power distribution, motor circuits, safety circuits, control networks, instrumentation. Include photographs of panels before and after wiring, close-ups of critical connections and labels showing cable identification. For LAPP components, reference datasheets are available through technical support and include dimensional drawings, material specifications and compliance statements.

The documentation proves the machine was built to specification and can be maintained safely. It protects the builder against future liability claims and gives the end user confidence in long-term reliability.

Talk to our engineers

LAPP SEA’s application engineers assist with connectivity commissioning planning, FAT preparation and SAT documentation packages. They review electrical designs for compliance with IEC 60204-1, recommend cable and connector combinations for specific machine environments and provide technical support during acceptance testing.

For pre-labelled cable assemblies that arrive ready for installation with test certificates, explore LAPP’s cable and connector portfolio. Pre-assembled harnesses arrive with test certificates attached, eliminating on-site labelling and reducing commissioning time significantly.

Contact the team to discuss your next project’s connectivity requirements and receive a customised commissioning checklist based on your machine type and acceptance test scope.