Energy Risk Professional (ERP)

Correct: According to SANS 10142-1 and general safety principles for integrated systems, emergency egress routes must be fail-safe. This means the locking mechanism must require continuous power to remain locked; if power is lost or the fire alarm circuit is interrupted, the circuit is de-energized and the doors automatically unlock. This ensures that life safety is prioritized over security during a power failure or emergency.

Incorrect: Fail-secure configurations are designed to keep doors locked during power failures, which is a hazard for emergency egress. Maintaining hold-down force during an alarm via a secondary power supply prevents evacuation and violates safety codes. Software-based interlocking introduces potential points of failure such as communication lag, bus errors, or controller crashes, making it less reliable than a hard-wired fail-safe electrical circuit.

Takeaway: Safety-critical integration of security and fire systems must employ fail-safe electrical designs that do not rely on active power or software logic to permit emergency egress.

Correct: SANS 10142-1 and standards for sensitive electronic equipment require the mitigation of electromagnetic interference (EMI) and harmonic distortion. Sharing a neutral with high-frequency switching power supplies introduces electrical noise that can corrupt data and cause controller malfunctions. A dedicated circuit with its own neutral is required. Furthermore, while functional earthing (clean earth) is used for noise reduction in security systems, it must be bonded to the main earthing terminal to ensure all parts of the installation remain at the same reference potential for safety and to prevent circulating currents.

Incorrect: Increasing the neutral conductor size addresses voltage drop but does not eliminate the harmonic noise or interference caused by sharing a neutral with non-linear loads. Software-based checksums or changing fail-safe modes are secondary measures that do not address the underlying electrical non-compliance or the physical cause of the hardware failure. Isolation transformers can provide some decoupling, but they do not replace the requirement for dedicated circuitry and proper bonding in a high-security environment, and they may introduce new impedance issues if not correctly integrated into the earthing system.

Takeaway: Sensitive electronic security systems must utilize dedicated circuits and proper functional earthing bonded to the main terminal to prevent interference and ensure operational reliability.

Correct: Fusion splicing is the preferred method for permanent backbone links because it creates a continuous glass path, resulting in the lowest possible insertion loss and highest mechanical strength. Adhering to the manufacturer’s minimum bend radius is critical to prevent macro-bending and micro-bending losses, which cause signal degradation and can lead to permanent physical damage to the glass core, especially in high-vibration environments.

Incorrect: Mechanical splicing is generally less reliable than fusion splicing and is more susceptible to misalignment and signal loss over time, particularly in environments with vibration. Ignoring bend radius constraints or exceeding tensile strength ratings during installation can cause immediate or latent failure of the fibre. Omitting the grounding of metallic strength members is a violation of general safety principles and SANS requirements regarding the bonding of metallic components to prevent potential differences.

Takeaway: Reliable fibre optic installations require fusion splicing for permanent links and strict adherence to physical handling specifications like bend radius and tensile strength to ensure signal integrity and safety.

Correct: According to SANS 10142-1 (The Wiring Code), any installation with an alternative supply must have a changeover device that ensures the two sources cannot be connected in parallel. This is a fundamental safety requirement to prevent back-feeding into the grid, which could endanger utility workers, and to protect the internal installation from damage during the restoration of the main supply.

Incorrect: Bypassing neutral-to-earth bonds is a major safety hazard and violates SANS 10142-1, as it prevents protective devices from functioning correctly. Manual procedures are insufficient for regulatory compliance because they are prone to human error and do not provide the fail-safe protection required by the Wiring Code. Bypassing the earthing system for sensitive equipment is a direct violation of the Occupational Health and Safety Act and SANS 10142-1, as it removes the primary protection against electric shock.

Takeaway: The primary regulatory requirement for load shedding backup systems is the implementation of a fail-safe changeover mechanism that prevents parallel supply connection.

Correct: According to SANS 10142-1, hinges, sliding parts, or similar mechanical connections are not considered reliable for maintaining electrical continuity for earthing purposes. A dedicated flexible conductor, such as a copper braid, must be installed to bridge the movable parts to the main earthed frame, ensuring that any fault current has a low-impedance path to ground and preventing the door from becoming live in the event of a fault.

Incorrect: Using conductive grease or cleaning paint from hinges are insufficient measures because mechanical movement, wear, and environmental corrosion can easily compromise the electrical path over time, making them non-compliant with the requirement for a permanent and reliable connection. Increasing the sensitivity of an earth leakage device is a secondary protection measure and does not fulfill the regulatory requirement for the primary bonding of exposed conductive parts.

Takeaway: In industrial control panels, movable metallic parts like doors must be bonded to the main frame using dedicated flexible conductors rather than relying on mechanical hinges for electrical continuity.

Correct: According to SANS 10142-1 (The Wiring Code), all exposed conductive parts of an electrical installation must be bonded to the main earthing terminal. This is to ensure equipotentiality, which prevents dangerous potential differences between metallic parts during a fault. Even if the devices operate at extra-low voltage (ELV), their metallic enclosures are part of the building’s environment and could become energized due to insulation failure in nearby higher-voltage circuits or lightning strikes.

Incorrect: The claim that DC-powered peripherals are exempt is incorrect because bonding is required for safety and equipotentiality, not just based on the operating voltage of the device itself. Suggesting a separate earth electrode for the security system is a violation of SANS 10142-1, as all earthing systems in a building must be interconnected to prevent potential differences. Limiting bonding only to the main control panel fails to protect personnel from electric shock at the peripheral device locations.

Takeaway: SANS 10142-1 requires all exposed conductive parts of an installation to be bonded to the main earthing terminal to maintain equipotentiality and ensure safety.

Correct: For Shielded Twisted Pair (STP) cabling to function correctly, the metallic shield must be continuous and bonded to the earthing system. This allows the shield to act as a Faraday cage, capturing electromagnetic interference and providing a safe, low-impedance path to ground for the induced currents. Without proper bonding, the shield can actually accumulate a charge or act as an antenna, worsening the interference it was meant to prevent.

Incorrect: Leaving the shield unbonded at both ends (floating) prevents the drainage of induced currents, rendering the shield ineffective against EMI. Connecting the shield to the neutral bar is a violation of SANS 10142-1 safety standards, as the neutral is a current-carrying conductor and could introduce noise or dangerous voltages into the data system. Isolating the shield from the earthing system entirely fails to provide the necessary path for interference dissipation and poses a safety risk during electrical faults.

Takeaway: Effective EMI protection in STP cabling requires a continuous shield that is properly bonded to the earthing system to safely dissipate induced currents.

Correct: According to SANS 10142-1, circuits of different voltage categories (such as Extra Low Voltage control signals and Low Voltage power) must be segregated. This is necessary to prevent hazardous voltages from being transferred to the control system during a fault and to minimize electromagnetic interference (EMI) which can cause malfunctions in the Building Management System. Using separate conduits or an earthed metallic partition is the standard method for achieving this safety and functional requirement.

Incorrect: The suggestion that insulation rating alone allows for the mixing of circuits is a common misconception; while insulation must be rated for the highest voltage, physical separation is still required for signal integrity and safety. The claim that analog signals are the only ones affected by interference is incorrect, as digital BMS signals are also highly susceptible to corruption from EMI. The idea that low current acts as a buffer is scientifically inaccurate and ignores the principles of electromagnetic induction and insulation breakdown.

Takeaway: Compliance with SANS 10142-1 requires strict segregation of control and power cabling to ensure both the electrical safety of the installation and the operational reliability of the Building Management System.

Correct: Under SANS 10142-1, when EVSE is installed in a TN-C-S system, there is a risk that a broken neutral in the utility supply could cause the vehicle’s chassis (connected to the protective earth) to reach a dangerous potential relative to the ground. To mitigate this, the auditor must verify that the design includes either a separate earth electrode (creating a TT system for the charger) or a specialized monitoring device that disconnects all conductors, including the earth, if a neutral fault is detected.

Incorrect: Sizing bonding conductors based on maximum demand is a general requirement but does not address the specific safety hazard of a broken neutral in a TN-C-S system. A Type A RCD is insufficient for EV charging infrastructure, which typically requires Type B RCDs to handle DC residual currents, and standard RCDs do not protect against neutral-to-earth voltage rises. Converting to an IT system is generally not a standard or practical solution for commercial EV installations and would introduce complex monitoring requirements that are outside the standard scope of SANS 10142-1 for this application.

Takeaway: Internal auditors must ensure that EV infrastructure designs specifically address the unique shock risks associated with TN-C-S earthing systems, such as the requirement for neutral-fault protection or independent earthing.

Correct: In Intrinsic Safety (IS), the safety of the system depends on the ‘entity’ concept. The associated apparatus (the barrier) is the energy source, and its maximum output parameters (Uo, Io, Po) must not exceed the safety ratings of the field device (Ui, Ii, Pi). If the barrier could provide more energy than the field device is certified to handle without sparking or overheating, the protection is compromised.

Incorrect: Option B is incorrect because the allowed external capacitance (Co) and inductance (Lo) of the barrier must be greater than or equal to the sum of the field device’s internal parameters (Ci, Li) plus the cable’s parameters (Cc, Lc). Option C is incorrect because associated apparatus like barriers are typically required to be located in a non-hazardous (safe) area. Option D is incorrect because IS circuits are generally earthed at only one point to prevent circulating ground currents that could introduce energy into the hazardous area.

Takeaway: Intrinsic safety requires that the energy-limiting parameters of the associated apparatus are strictly matched to be lower than or equal to the safety input ratings of the field device.