Proper cable termination and testing in medium voltage (MV) installations are critical to ensuring operational safety, reliability, and system longevity. Cable joints and terminations are common failure points if not executed with precision and compliance to manufacturer and international standards such as IEC 60502-4 or IEEE 400.
At OXCART Power System Engineering, we approach every MV installation with a standardized cable preparation and testing protocol. The process begins with verifying cable specifications — insulation type, shielding material, conductor size — to match the chosen termination kits. We use only approved and certified accessories (e.g., cold-shrink or heat-shrink kits) from manufacturers like Raychem, Nexans, or 3M.
**Termination Process Overview:**
- Visual inspection and cable ID verification
- Accurate strip-back of insulation and semiconductive layers
- Precision crimping of lugs using calibrated hydraulic tools
- Proper grounding and sealing of metallic screens
- Moisture barrier application to prevent partial discharge
**Testing Methods After Termination:**
1. **Insulation Resistance Test (IR):** Conducted with a 5kV megger, ensures basic insulation health.
2. **Very Low Frequency (VLF) Testing:** Especially useful for XLPE-insulated cables, simulates AC stress.
3. **Partial Discharge (PD) Detection:** Identifies microvoids or installation errors before energization.
4. **Tan Delta Measurements:** Evaluates dielectric losses to predict aging.
We document every step with digital test reports, including waveform screenshots and technician sign-offs. Improper terminations often lead to thermal hotspots, corona discharge, or tracking failures, which can be catastrophic in substations or process industries.
In this blog, we share real-world case studies of termination failures, explore field best practices, and provide a checklist that every project engineer and technician should follow before closing the panel door. Cable termination isn't just about joining conductors — it’s about preserving the heart of your power system.
