# Cable Termination and Testing Termination and testing from DC string level to 132 kV. Source: https://crestwatt.com/services/cable-termination-testing/ Publisher: CrestWatt — Electrical contracting for utility-scale solar, storage and grid connections. Contact: info@crestwatt.com Language: en-GB Cable termination on a utility-scale plant covers several distinct trades: DC crimping and connector assembly, LV and MV terminations, HV terminations and sealing ends, fibre optic splicing, and communications and control cabling. Each has its own tooling, its own standard and its own test regime. CrestWatt delivers all of them under one scope, with one records system, so that the test certificate for a string, a 33 kV feeder and a fibre link all sit in the same handover pack. **Standards and methods cited:** IEC 60352-2, IEC 62852, IEC 61280-4-1, IEC 61300-3-35, ISO/IEC 11801, EN 50173, EN 50174, IEEE 400.2, IEC 60229 ## DC cabling and connectors - DC cable crimping to IEC 60352-2 using manufacturer-specified dies and calibrated crimp tooling; crimp pull testing to sample plan - MC4 and MC4-EVO2 connector assembly and crimping to IEC 62852 and manufacturer instructions, with connector compatibility verified against module and combiner box types - DC cable lug termination at combiner boxes and inverters, torque recorded - String polarity, continuity and insulation resistance testing at termination ## LV and MV cable termination - LV terminations at inverter, transformer station and LVAC distribution - MV terminations 11 kV and 33 kV: heat shrink, cold shrink and separable (elbow and T-body) connectors, to manufacturer instructions and cable type - Straight joints and transition joints - Torque and phasing records for every termination ## HV cable termination - 66 kV and 132 kV outdoor sealing ends, GIS plug-in terminations and transformer bushing terminations - Cable preparation, semi-conductive screen removal and stress control to manufacturer procedure - Terminator-certified jointers for the accessory type installed - Earth bonding of cable screens and sheath voltage limiters where specified ## Optical fibre - Fusion splicing and pigtail termination, single mode and multimode - Patch panel and splice enclosure population to the plant splicing plan - OTDR trace and bidirectional insertion loss testing to IEC 61280-4-1 for every link, with trace files delivered - End-face inspection and cleaning to IEC 61300-3-35 ## Modbus and control cabling - Modbus RTU over RS-485: shielded twisted pair termination, daisy-chain topology verification, 120 Ω line termination and bias resistor checks, shield earthing at one point only - Device addressing and baud rate verification against the plant register map - Loop continuity, insulation and polarity testing; communications verified end to end from the field device to the SCADA server - Control and instrumentation wiring termination, ferruling and point to point checks ## Structured cabling - CAT5e, CAT6, CAT6A and CAT7 termination and certification to ISO/IEC 11801 and EN 50173, with test results delivered per link - Installation to EN 50174 separation and routing requirements ## HV cable testing - Insulation resistance - VLF withstand at 0.1 Hz to IEEE 400.2 - DC sheath integrity testing to IEC 60229 and manufacturer requirement - Tan delta and partial discharge where specified by the client or DNO - Phasing and phase rotation - TDR for fault location and pre-termination length verification - Pre-termination and post-termination testing recorded separately ## Records Every termination and test is recorded on site on the day of completion, with cable identity, accessory type and batch, tooling and instrument reference, result, engineer and witness. Records are delivered in a structured format and compiled into the handover pack. ## Next step Send the cable schedule and the accessory specification. We will confirm certification coverage, tooling and a programme. ## Common questions **Which cable terminations does CrestWatt carry out?** DC crimping and MC4 connector assembly at string level; LV terminations at inverter, transformer station and LVAC distribution; 11 kV and 33 kV heat shrink, cold shrink and separable connector terminations; and 66 kV and 132 kV outdoor sealing ends, GIS plug-ins and transformer bushing terminations. **What HV cable tests are offered?** Insulation resistance, VLF withstand at 0.1 Hz to IEEE 400.2, DC sheath integrity testing to IEC 60229, tan delta and partial discharge where specified, phasing and phase rotation, and TDR for fault location and length verification. Pre-termination and post-termination results are recorded separately. **Is fibre optic and data cabling included?** Yes. Fusion splicing and pigtail termination, patch panel and splice enclosure population to the plant splicing plan, OTDR and bidirectional insertion loss testing to IEC 61280-4-1 with trace files delivered, and CAT5e to CAT7 certification to ISO/IEC 11801 and EN 50173. **How is Modbus cabling terminated and proved?** Shielded twisted pair termination with daisy-chain topology verification, 120 Ω line termination and bias resistor checks, and shield earthing at one point only. Device addressing and baud rate are verified against the plant register map, and communications are proved end to end from the field device to the SCADA server. ## Related scopes - [Testing and Commissioning](https://crestwatt.com/services/testing-commissioning/): IEC 62446-1 DC commissioning; AC, LV and HV pre-energisation testing; protection commissioning; SCADA point to point; witness testing; FAC compilation. - [HV Substation and Cable Works](https://crestwatt.com/services/hv-substation-cable-works/): Substation electrical packages and HV cable supply and installation, 11 kV to 132 kV, including switchgear, transformers, DC auxiliary systems and cable accessories. - [Protection, Control and Switchgear](https://crestwatt.com/services/protection-control-switchgear/): Relay, CT and VT supply; panel design, build and wiring; IEC 61850 configuration; settings; secondary and primary injection; site acceptance.