Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
CSA C68.1-92 (2019): Shielded and Armoured Power Cables for Mining Applications – Specifications and Compliance
A comprehensive overview of the Canadian standard for insulated power cables used in underground and surface mining operations
Scope
CSA C68.1-92 (2019) is a revised edition of the original 1992 standard, reaffirmed with updates to maintain relevance for the modern mining industry. The standard specifies requirements for shielded and armoured power cables intended for use in both underground and surface mining operations. It covers cables rated for voltages up to 5 kV (phase-to-phase) and is applicable to constructions used for supplying power to mobile equipment such as shuttle cars, continuous miners, drills, shovels, and other heavy machinery. The standard includes cables that are intended to be flexible, durable, and resistant to the harsh conditions typical of mining environments, including physical wear, moisture, chemicals, and flame propagation.
Technical Requirements
Construction and Materials
CSA C68.1-92 (2019) defines specific construction requirements to ensure mechanical and electrical integrity. Conductors must be stranded copper of a flexible class (e.g., Class D or K stranding) to allow repeated bending without fatigue. Insulation is typically ethylene propylene rubber (EPR) or cross-linked polyethylene (XLPE) with a minimum thickness dependent on the voltage rating. Each insulated conductor is covered with a conductor shield and an insulation shield that must meet conductivity and strippability criteria. The armour layer, which provides mechanical protection and may serve as a grounding conductor, must be either a tinned copper braid or a helical steel wire armour, depending on the cable type. The outer jacket is made from a tough thermoset material such as chlorinated polyethylene (CPE) or chlorosulfonated polyethylene (CSPE), formulated to resist flame, oil, and abrasion.
Electrical Tests
All cables must pass a series of standardised electrical tests to confirm their insulating and shielding properties. These tests are performed on finished cable samples under controlled conditions:
- Dielectric withstand test (AC): 5 kV rated cables are subjected to 10 kV RMS for 5 minutes without breakdown.
- Impulse voltage test: A minimum of 20 kV (peak) for types up to 5 kV rated, with ten positive and ten negative impulses.
- Insulation resistance measurement: After immersion in water at 75 °C for several hours, the insulation resistance is measured and must exceed a specified minimum (typically 200 MΩ·km).
- DC voltage test: Applied for 15 minutes at 15 kV DC, verifying no leakage current beyond allowed limits.
Mechanical and Environmental Tests
To simulate severe mining conditions, the standard mandates flame testing to CSA C22.2 No. 0.3 (vertical tray test) or equivalent, requiring a limited char length and extinguishing time. Additional tests include:
| Test Parameter | Requirement |
|---|---|
| Abrasion Resistance | Weight loss ≤ 1.0 g after 500 cycles on an abrasive belt |
| Cold Bend at –40 °C | No visible cracking after bending over a mandrel 6× cable diameter |
| Flexibility (Mandrel Wrap) | One wrap around a mandrel 10× cable diameter without damage |
| Oil Resistance (ASTM #2 oil, 24 h @ 70 °C) | Tensile strength retention ≥ 75%, elongation ≥ 60% |
| Flame Test (CSA C22.2 No. 0.3) | Char length ≤ 1.5 m, time to extinguishment ≤ 60 s |
Implementation Highlights
When applying CSA C68.1-92 (2019) cables in a mining installation, the selection of the correct cable type depends on the application voltage, current-carrying capacity, and environmental factors such as surface or underground use, risk of abrasive wear, and exposure to moisture or chemicals. The standard defines multiple cable type designations (e.g., SHD, G-GC, W) based on shield configuration and armour type.
Tip: For trailing cables subject to repeated flexing and potential tension, specify a heavy-duty braid armour and a reinforced jacket to extend service life. Always verify that the cable’s minimum bending radius value is included in the manufacturer’s specifications to avoid kinking during installation.
Colour coding of the grounding conductor is critical. In all CSA C68.1-92 (2019) cables that incorporate a ground-check conductor, the insulation must be green/yellow striped, and the main grounding conductor must be bare or a distinct colour such as green. Proper identification aids compliance with the Canadian Electrical Code, Part I (CSA C22.1).
Installation practices must follow the National Standard of Canada for electrical installations; cables certified to CSA C68.1-92 (2019) carry the CSA mark and are listed in the appropriate product directories. When used in hazardous locations (e.g., explosive gas or dust zones), these cables must be applied in accordance with the relevant area classification requirements.
Warning: Do not exceed the maximum rated voltage or the cable’s short‑circuit current rating. Overvoltage conditions, even for short durations, can damage the insulation shield interface and lead to premature failure. Always coordinate cable ampacity with overcurrent protection devices per the Canadian Electrical Code.
Compliance Notes
CSA C68.1-92 (2019) is a harmonised Canadian standard recognised by regulatory authorities across all provinces and territories. Certification to this standard is typically performed by independent organisations such as CSA Group, UL, or Intertek, which conduct type tests and quarterly factory inspections to ensure ongoing compliance.
Because the standard was reaffirmed in 2019 after a systematic review, it is considered current for new installations. However, users should check for any amendment sheets (e.g., CSA C68.1-92 (R2019) A1) that may address specific clarifications or updated test methods. It is advisable to consult the latest edition of CSA C68.1-92 (R2019) and its accompanying amendments when specifying or procuring mining cables.
Compliance Advantage: Using cables certified to CSA C68.1-92 (2019) simplifies mine site inspections, reduces the risk of electrical failures, and is often a prerequisite for obtaining mine safety permits. The standard’s rigorous tests provide high confidence in cable durability and reliability.
Risk of Non‑Compliance: Substituting cables that meet other standards, such as ICEA or UL, without verifying equivalency to CSA C68.1-92 (2019) may violate local mining regulations and void warranty coverage. Differences in armour design, flame resistance, or grounding conductor requirements can create serious safety hazards.
Frequently Asked Questions
Q: Is CSA C68.1-92 (2019) mandatory for all mining cables in Canada?
A: Yes, most Canadian mining jurisdictions require that portable power cables used in mines meet CSA C68.1-92 (2019) or an equivalent, as adopted by reference in the provincial mining regulations and the Canadian Electrical Code. Always check with the local regulatory authority for specific adoption details.
A: Yes, most Canadian mining jurisdictions require that portable power cables used in mines meet CSA C68.1-92 (2019) or an equivalent, as adopted by reference in the provincial mining regulations and the Canadian Electrical Code. Always check with the local regulatory authority for specific adoption details.
Q: What is the difference between CSA C68.1 and CSA C68.2 standards?
A: CSA C68.1 covers shielded and armoured power cables primarily for mobile mining equipment up to 5 kV, whereas CSA C68.2 addresses medium-voltage power cables for fixed or permanent installations in mining (e.g., network feeder cables above 5 kV). The construction and testing requirements differ, particularly for insulation level and armour type.
A: CSA C68.1 covers shielded and armoured power cables primarily for mobile mining equipment up to 5 kV, whereas CSA C68.2 addresses medium-voltage power cables for fixed or permanent installations in mining (e.g., network feeder cables above 5 kV). The construction and testing requirements differ, particularly for insulation level and armour type.
Q: Can CSA C68.1-92 (2019) cables be used in underground non‑gassy (non-hazardous) mines?
A: Yes, these cables are fully suitable for non-gassy (non-coal) mines. However, they also meet flame‑propagation requirements that make them acceptable in gassy (coal) mines provided they are installed in accordance with Part 23 of the Canadian Electrical Code and any additional mine‑specific conditions.
A: Yes, these cables are fully suitable for non-gassy (non-coal) mines. However, they also meet flame‑propagation requirements that make them acceptable in gassy (coal) mines provided they are installed in accordance with Part 23 of the Canadian Electrical Code and any additional mine‑specific conditions.
Year of publication: 2026. This article summarises key aspects of CSA C68.1-92 (2019) for informational purposes. Always refer to the official standard for complete details.