Safety Regulations for Utility Vaults and Access

<p>They must be locked unless authorized personnel are present. (C)</p> Signup and view all the answers

<p>To ensure that the door can be opened from the inside even when locked from the outside. (D)</p> Signup and view all the answers

<p>The same clearance as specified in Rule 110A2. (D)</p> Signup and view all the answers

<p>They must be corrosion-resistant. (C)</p> Signup and view all the answers

<p>They should be equipped with louvers or baffles to prevent object penetration. (B)</p> Signup and view all the answers

<p>All of the above, provided all parties involved agree and applicable rules are met. (D)</p> Signup and view all the answers

<p>22,000 V (D)</p> Signup and view all the answers

<p>Effectively grounded concentric shield construction (C)</p> Signup and view all the answers

<p>To detect and signal a ground fault within the circuit. (B)</p> Signup and view all the answers

<p>They must have a continuous metallic shield under the outer jacket. (A)</p> Signup and view all the answers

<p>5,300 V (C)</p> Signup and view all the answers

<p>Communications-protective devices adequate for the expected voltage and currents (A)</p> Signup and view all the answers

<p>100   m (C)</p> Signup and view all the answers

<p>By measuring the resistance between the concentric neutral and a surrounding conducting medium, multiplying by the surface area and dividing by the thickness. (A)</p> Signup and view all the answers

<p>The concentric conductor must be grounded at each service. (A)</p> Signup and view all the answers

<p>When adherence would require opening a duct and/or removing the protective jacket of the buried cable only for the purpose of installing a ground connection. (D)</p> Signup and view all the answers

<p>8 (D)</p> Signup and view all the answers

<p>Only in nonmetallic ducts (B)</p> Signup and view all the answers

<p>The electric utility and the owner of the property (C)</p> Signup and view all the answers

<p>To ensure that the fault current is diverted to ground safely. (D)</p> Signup and view all the answers

<p>Corrosion-resistant (C)</p> Signup and view all the answers

<p>Below communication cables (A)</p> Signup and view all the answers

<p>Cable movement should be allowed, ensuring no stress concentration (A)</p> Signup and view all the answers

<p>Agreement from all involved parties (D)</p> Signup and view all the answers

<p>At the cable entrance to the duct (A)</p> Signup and view all the answers

<p>To facilitate identification and maintenance (D)</p> Signup and view all the answers

<p>As specified in Table 341-1 (C)</p> Signup and view all the answers

<p>By using tags with the utility name and cable type (C)</p> Signup and view all the answers

<p>1.83 m (A)</p> Signup and view all the answers

<p>900 mm (D)</p> Signup and view all the answers

<p>To account for the impact of heavy vehicles and equipment. (B)</p> Signup and view all the answers

<p>14.5 kPa (D)</p> Signup and view all the answers

<p>The maximum combination of vertical and lateral loads that will be imposed on the structure. (D)</p> Signup and view all the answers

<p>Tractor-semitrailer trucks. (C)</p> Signup and view all the answers

<p>They should be designed to withstand twice the expected load. (B)</p> Signup and view all the answers

<p>By ensuring the manhole's weight is sufficient or by restraining it to withstand the forces. (B)</p> Signup and view all the answers

<p>Interference with data transmission due to electromagnetic induction. (C)</p> Signup and view all the answers

<p>300 V (A)</p> Signup and view all the answers

<p>All of the above are acceptable configurations. (D)</p> Signup and view all the answers

<p>When the cable passes through a short section of conduit, such as under a roadway. (A)</p> Signup and view all the answers

<p>They must be made of a material that is corrosion-resistant. (A)</p> Signup and view all the answers

<p>They are susceptible to corrosion in the presence of moisture and soil chemicals. (B)</p> Signup and view all the answers

<p>To prevent the jacket from degrading and compromising the conductor's integrity. (C)</p> Signup and view all the answers

<p>To avoid interference with communication signals caused by electromagnetic induction from ground currents. (B)</p> Signup and view all the answers

Manholes must sustain all expected loads, including dead, live, equipment, impact, and environmental loads.

The permanent static load that a structure must support, such as the weight of the structure itself.

The variable load that may change over time, such as vehicles passing over a structure.

An increase in live load by 30% to account for sudden forces, like a truck hitting a bump.

Forces acting on the structure horizontally, which can affect its stability.

A condition where frost can push structures upward, requiring designs to withstand this force.

Manholes must have a clear working space of at least 900 mm (3 ft) wide and 1.83 m (6 ft) high.

Facilities for pulling iron should withstand twice the expected load applied during use.

Covers must be heavy or designed to prevent removal without tools.

Covers must not fall into manholes or touch cables/equipment.

Covers must support applicable loads as per Rule 323A.

Access openings should ensure safe passage and not align over equipment.

Public access doors must be locked unless authorized personnel are present.

Prominent signs must be posted near exposed live parts.

Doors should allow exiting from inside even when locked outside.

Energized parts must have a safety clearance from ventilation openings.

Supply and communication cables may be buried together if agreed and rules are met.

Dielectric fiber-optic cables can be buried with supply cables without separation under specific agreements.

Grounded supply systems should not exceed 22,000 V to ground.

Ungrounded systems must not exceed 5,300 V phase-to-phase.

Ungrounded supply cables over 300 V must be effectively grounded concentric shield type.

Ungrounded circuits over 300 V must have a ground-fault indication system.

Communication cables with metallic parts must have a continuous metallic shield.

Bonding between supply conductors and cable shields should not exceed 300 m (1000 ft).

Evaluate communication circuits near supply stations to prevent interference from large ground currents.

Supply facilities above 300 V must have a grounded conductor continuously in contact with earth.

Grounded conductors can be a sheath, insulation shield, or multiple concentric conductors.

A separate conductor in contact with earth should be close to the cable for grounding.

When a cable passes through a conduit, grounding can be omitted if continuous through conduit.

Bare conductors contacting earth must be made of corrosion-resistant materials.

Conductors under semiconducting jackets must be compatible with the jacketing compound.

Experience shows bare concentric copper neutrals can corrode severely in many areas.

Cables must allow movement without stress concentration and stay supported during operation.

Adequate space must be provided as per Rule 323B for cable installation.

Installing cables in a shared manhole requires agreement from all utilities involved.

Supply and communication cables should be racked separately; if not, supply cables go below.

Facilities must be installed to allow access without moving other cables.

Cables must be permanently marked at access points for identification.

Tags for cable identification should resist corrosion and be readable in low light.

Cables in joint-use areas should be marked with utility names and cable types.

The measurement of resistance in the semiconducting jacket material of cables, ideally not exceeding 100 Ω·m.

Each phase conductor above 300 V must have an effectively grounded copper concentric conductor meeting safety codes.

The magnitude and duration of abnormal current that can occur during a fault condition in electrical systems.

A grounded copper conductor that surrounds the phase conductors, providing safety and stability.

Conductors placed in the ground to safely disperse electrical faults, with at least eight required per 1.6 km.

Grounded neutral supply cables can be laid randomly with communication cables in nonmetallic ducts.

Cables used for transmitting information, which can run alongside supply cables in certain installations.

Supply cables and non-metallic lines may be buried at the same depth if all parties agree.