The problem: loop testing is on the critical path

In large-scale industrial projects (FPSO, LNG terminals, refineries), the commissioning phase is where accumulated delays converge. Loop testing — the fundamental verification of every instrumentation loop from field device to control system — is one of the most time-consuming activities.

Industry benchmarks show that traditional loop checks require 2.5 to 4.0 man-hours per loop. For a mega-project with 20,000 I/O points, this creates a demand for 50,000 to 80,000 skilled man-hours, precisely when the project is under maximum schedule pressure.

The core constraint: traditional methods depend on the permanent DCS and Control Room being fully operational. Until the Field Instrument Room (FIR), marshalling cabinets, and DCS I/O cards are commissioned, no loop testing can begin. This dependency locks loop testing onto the critical path.

Typical delays and costs

• 98% of projects experience commissioning delays
• $1M+ per day in delay costs on major offshore projects
• 3 to 6 months of typical schedule overrun during commissioning
• 60 to 120 minutes per loop with traditional 2-technician methods

Our approach: Advanced Loop Check (ALC)

Advanced Loop Checks replace physical signal injection with digital interrogation. By commanding smart instruments (HART, Foundation Fieldbus, Profibus PA) to simulate process variables via their digital protocol, the entire measurement chain can be validated remotely — from the device electronics, through field wiring and marshalling, to the I/O card and HMI.

FARAMED's ALC methodology goes further: we decouple loop testing from the permanent DCS entirely. Using our Pelicase portable test nodes connected at Junction Box level, we can begin field verification as soon as field cabling is installed — months before the Control Room or DCS is ready.

Key principle: the decoupling

• Traditional: Sensor → JB → Multicore → Marshalling → DCS — 60 min/loop, 2 technicians, 100% sequential
• ALC with Pelicase: Sensor → JB → Pelicase (temporary DCS) — 5 min/loop, 1 technician + automation, parallel testing

The Pelicase system: field-side execution

The Pelicase is the field-side execution block of the ALC method. Positioned at the Junction Box, it acts as a temporary local interface between installed instruments and the Mobile Control Room.

Each Pelicase aggregates multiple loop signals from one JB or field area and makes them available for structured testing from the commissioning container. This enables parallel field verification: one field connection point, multiple loop channels, remote supervision, and automated test sequences.

Pelicase capabilities

• Temporary 24 VDC loop power supply
• Analog input/output channels (4-20mA)
• Digital input/output channels
• HART protocol access for smart instrument interrogation
• Communication gateway (wireless 900 MHz or Ethernet)
• Local isolation and protection
• Environmental protection for temporary field deployment

Non-intrusive connection

The Pelicase connects at the JB using a make-before-break methodology. The temporary connection is established before the permanent wiring is disconnected, ensuring zero interruption to any existing signals. When ALC is complete, the permanent path is restored with full traceability.

Five Pelicase configurations

• PSU Pelicase — Power supply unit providing 24VDC to instrument loops via JB
• PCS Pelicase — Process Control System node with Universal I/O for analog and digital loops
• PSD Pelicase — Process Shutdown / Safety node for ESD and SIS loops (SIL 2-3)
• FG Pelicase — Fire & Gas detection system testing node
• Package Pelicase — Special I/O node for rotating equipment packages (compressors, turbines, pumps with VFD)

Mobile Control Room: the supervision layer

The Mobile Control Room (MCR) is a containerized command center that serves as the temporary DCS during ALC operations. It provides the engineering-grade environment to read loop values, inject test signals, interrogate smart instruments, compare actual data with expected data, guide troubleshooting, and record structured test evidence.

MCR specifications

• Climate-controlled 20ft container with integrated 10ft technical room
• Complete rack server bay with redundant Ethernet switches
• Engineering workstations with HMI pages for loop status
• Loop database linked to Instrument Index
• Automated test scripts and reporting layer
• UPS systems with distribution cabinets
• Pre-configured for client I/O list and P&ID
• Operational within 48 hours of site delivery
• Capacity: 60 simultaneous loops under test

Methodology: three phases of deployment

Phase 1 — Test at Junction Box level

Condition: Instruments and field cables are installed, but multicore cables to FIR are not yet pulled or terminated.

Method: Pelicase connects directly to JB terminals. Loops are powered, instruments are interrogated via HART/4-20mA, scales and alarms are validated.

Scope validated: Instrument + field cable + JB termination.

Phase 2 — Test JB to Marshalling

Condition: Multicore cables are pulled and terminated at both ends.

Method: Pelicase at JB level sends signals through multicore to marshalling cabinet. End-to-end continuity and signal integrity are verified.

Scope validated: Full cable path from instrument to marshalling rack.

Phase 3 — Credit Transfer to permanent DCS

Condition: Permanent DCS is ready.

Method: ALC results are transferred as verified credits. Only the final DCS-to-marshalling segment requires testing — reducing permanent system commissioning to a fraction of the original scope.

Contractual basis: IEC 62382 clause 6 provides the framework for Credit Transfer acceptance by EPC and Owner.

Performance data: proven results

Productivity gains

• 8-12 loops tested per day per Pelicase (vs. 3-5 traditional)
• 25-40 minutes per loop (vs. 90-120 minutes traditional)
• 150% productivity increase over conventional methods
• 75% reduction in time per loop

Project economics

• ROI: 380-750% depending on project scale
• Payback period: 1.5-2.5 months
• Year 1 savings: $524K-$791K on a single FPSO
• 5-year NPV: $1.2M-$4.2M for multi-project scaling
• Unit cost reduction: 50-60% ($800-1,200 vs. $2,000-3,000 per loop)

Schedule impact

• 4-5 weeks saved vs. 8-10 weeks traditional (50% compression)
• 277 man-days saved on a 10,000-loop project
• Schedule compression from 25 weeks to 6 weeks on major projects

Quality and safety

• Less than 5% residual defect rate
• 0.00 TRIR across all deployments
• 100% automated documentation — digitally signed test reports

Sizing scenarios

Scenario A — Medium project (gas treatment unit, brownfield): 5,000 loops, 120 JBs, 8 Pelicases, 6 weeks ALC duration, 7,500 man-hours saved.

Scenario B — Large project (FPSO or LNG terminal): 10,000 loops, 250 JBs, 13 Pelicases, 6 weeks ALC duration.

Scenario C — Mega-project (integrated refinery or offshore complex): 20,000 loops, 500+ JBs, 20+ Pelicases.

Where ALC applies

• FPSO greenfield — Full instrumentation commissioning
• Brownfield FPSO upgrades — Partial system replacement
• Fixed offshore platforms — North Sea, Gulf of Mexico, Southeast Asia
• Refineries — Large instrumentation scopes
• LNG terminals — Cryogenic and process control loops
• Subsea tie-backs — Mudline JB testing

The method works with both Centralized architectures (JB → Home Run → Central Marshalling → DCS) and Remote I/O architectures (JB → Field Cabinet → Ethernet → DCS).

Compliance and standards

• IEC 62382 — Electrical and instrumentation loop check (FAT/SAT integration)
• IEC 61508 — Functional safety, SIL 2-3 for safety-critical loops
• IEC 61511 — Safety instrumented systems for the process industry
• IEC 62443 — Industrial cybersecurity (Pelicase fleet operates in isolated VLAN with DPI firewalls)
• ISO 17025 — Calibration and testing laboratory competence
• NAMUR NE43 — Signal level standardization for failure information

Frequently asked questions

Can ALC work with our existing centralized DCS architecture?

Yes. Our methodology is specifically designed for centralized architectures (JB → multicore → marshalling → DCS). The Pelicase connects at JB level and validates the field portion independently of the permanent system architecture.

How does the Credit Transfer work contractually?

IEC 62382 clause 6 provides the framework. All ALC test results are documented with digital signatures, time stamps, and complete loop data packages. When the permanent DCS comes online, only the final segment (marshalling → DCS I/O card) needs verification. The EPC and Owner review the ALC evidence package and accept credited loops.

Is the Pelicase connection safe for live instruments?

The make-before-break connection methodology ensures zero interruption. The temporary path is established and verified before any permanent connection is modified. All Pelicase operations follow strict isolation procedures with checklists and restoration verification.

What about ATEX/hazardous area requirements?

The Pelicase is designed for temporary deployment in classified areas. Specific configurations are available for Zone 1 and Zone 2 requirements. The MCR container operates from a safe area with wireless connectivity to field Pelicases.

What documentation do we receive?

Complete digital test packages including: loop test results with 5-point signal verification, HART device configuration records, deficiency classification (installation/configuration/engineering), digitally signed completion certificates, and IEC 62382-compliant handover documentation.

How quickly can you mobilize?

The MCR is operational within 48 hours of site delivery. Pelicase deployment to field JBs takes 1-2 days per work front. A typical 5,000-loop project reaches full testing capacity within the first week.

Ready to remove loop testing from your critical path?

Contact our engineering team to discuss your project scope, I/O count, and schedule constraints. We will provide a tailored deployment plan with projected schedule savings and cost analysis.