Insulated Working Under Impressed Voltage Conditions (NSI5 Equivalent for Contractors)

Course details

Insulated Working Under Impressed Voltage Conditions equips utility contractors with the skills to safely perform insulated working on HV and LV cable systems under impressed voltage conditions, in line with National Grid’s NSI‑5 technical guidance. Ideal for those working on overheard line-connected cable routes, the course combines theoretical instruction and practical, scenario-based learning to manage fault, induced, capacitive, and EPR hazard awareness.

Course Duration – 1 Day

Who Should Attend?

This course is designed for:

• HV/LV cable contractors working with systems under impressed voltage
• Competent Persons seeking EUSR NSI‑5 endorsement
• Site personnel involved in insulated working environments
• Utility engineers and supervisors managing NV/LV cable sheath or accessories

What You’ll Learn

• Definition and risk factors of impressed voltage conditions
• Regulations and management systems under NSI‑5 and National Grid Safety Rules
• Hazard recognition: induced voltage, dielectric polarization, EPR, stray currents
• Insulated and earthed working protocols, bonding, spiking, cable sheath tests
• Use of insulated PPE: platform, boots, gloves, tools, mats
• Permit processes, safety documentation, and competent oversight

Course Content

• Impressed Voltage
• Purpose and Scope
• Definitions
• Dangers
• General Requirements for Work on Cable Systems
• General Requirements for Work on LV Cables
• General Principles for Work on HV and LV Cables Subject to Impressed Conditions
• Work on HV Cable Sheath Disconnecting Link Boxes and Link Pillars under Impressed Conditions
• Procedure for Cable Serving Test under a Permit for Work
• Work on Metallic Cooling Pipes under Impressed Conditions
• Work on or near Faulty or Damaged HV and LV Cables

Assessment

Delegates will be evaluated through a combination of practical exercises, oral questioning, multiple-choice assessments, and written responses, ensuring a comprehensive understanding of the course material.

Certificates

Upon successful completion of the course and assessment activities, delegates will receive their results and be issued with a formal in-house certificate of achievement.

This certification is valid for a period of one year from the date of training.

Pre-Requisites

National Grid Competent Person Substations NSI 6 and NSI 8 and a good understanding of cable systems.