Frequently Asked Questions

Frequently Asked Questions

  1. Question: What is Cable Bus?

    Answer: Cable Bus is a system for distributing power from one electrical apparatus to another using insulated power cables inside of a protective metal housing.

    Get an Overview of Cable Bus systems

    Learn more about how Cable Bus compares to other LV & MV power distribution systems

  2. Question: What if I have questions during installation?

    Answer: Our office is open Monday through Friday, 9:00AM to 5:00PM. Our engineering staff is standing-by, ready to answer any questions you have or provide any additional information you might need to install and power-up your Advanced Cable Bus system. Please feel free to call or e-mail us at your convenience.

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  3. Question: Why should I choose Cable Bus?

    Answer:Each electrical feeder has its own requirements, and while Cable Bus is versatile and cost-effective, there are certain circumstances where other options are viable. The physical attributes to watch out for include:
    Flexibility —
    Cable Bus systems combine the installation flexibility of cable trays and conduits and the system reliability and heavy-duty properties of rigid bus ducts. When unexpected changes to the route of the feeder is anticipated, Cable Bus enclosures and cables can be modified to meet on-site changes.
    Bending Radius —
    Power cables have minimum bending radius (from 6 x OD up to 12 x OD) that may be difficult to install for tight sharp turns. At low voltages, diesel locomotive (DLO) type cables may be used to allow tighter bends.
    Installation space & access —
    In order to install Cable Bus, there has to be space to pull cables into place, tighten the support blocks, and fasten the covers. This typically requires 8”-12” of space above the Cable Bus.
    Length of circuit —
    Cable Bus generally has better voltage drop and power losses compared to other feeder types of the same voltage and current ratings. When circuits get too short and there’s no space to terminate the cables, rigid bus ducts may be suitable. For very long circuits, step-up transformers and higher voltage transmission may be more economical.
    Electrical properties —
    In long circuits, Cable Bus has the best voltage drop and power losses compared to similar feeder options.
    Feeder Taps —
    Because Cable Bus systems are comprised of power cables, each tap point usually requires a tap box that allows cables to terminate with sufficient space clearances. Circuits with multiple taps will require space for tap boxes.

    Learn more about how Cable Bus compares to other LV & MV power distribution systems

  4. Question: Can you rush our job? We're short on time.

    Answer: The normal steps for Cable Bus projects begin with Advanced Cable Bus requesting engineering information from our client, then generate drawings to be submitted for approval, and we begin manufacturing upon approval from our client. The lead times for manufacturing and engineering drawings depend on the current work load and contacting us [hyperlink] to find out the lead time is recommended. The time to compile engineering information and review drawings can be variables that extend the project time. Another possible source of delay is availability of power cables if the specification calls for non-stocked cables.

    Therefore, the fastest way to get Cable Bus manufactured and shipped would be to directly release the enclosures to production, which circumvents the drawing stages. By reviewing the project prior to releasing, Advanced Cable Bus can release sufficient 12-foot sections and elbows to cover the project requirements. The installers can cut the enclosure sections to fit their needs on-site and either determine the required cable lengths after the enclosure is in place or order a release of cables with extra spare lengths. Advanced Cable Bus always ships Cable Bus projects with installation spares for enclosures and extra lengths for cable reels to account for minor field changes.

  5. Question: How do I request quotes or determine lead times for Cable Bus projects?

    Answer: You can request quotes by going to our Request a Quote page. In order to determine the lead times, please contact us.

    Contact Advanced Cable Bus

  6. Question: I do not have any specifications or technical guidelines for the system. How will the Cable Bus system be designed?

    Answer: If there are no specifications or technical requirements, Advanced Cable Bus, Inc. will follow the electrical code of your location. US-based locations will have NEC/IEEE based designs, while Canadian systems will follow CSA rules. International projects will follow the local governing authorities where applicable, and Advanced Cable Bus will state clearly the basis for our design choices.

    Contact Advanced Cable Bus

  7. Question: What other online resources can you provide?

    Answer: Advanced Cable Bus has online presentations on the Cable Bus basics and introduction to Cable Bus engineering and installation available via YouTube. We also have sample drawings and installation manual available by request as well as test reports and certificates. We are also able to provide you with installation and testing guidelines for cables and other sub-components of the system.

    Contact Advanced Cable Bus


System Selection Tips

Tips for Selecting a System

  1. Determine the rated voltage and current of the circuit under consideration.

    Cable bus is a suitable option for voltages between 208V and 35kV, and in rare cases, 69kV. Range of suitable currents is from 1200A to 6000A, and slightly outside that range in rare cases.

    Most feeders that use cable bus connect major equipment, such as switchgear, transformer, and motor control centers.

    Typical circuits will be rated to cover the more critical current rating of the connected equipment, such as the breaker rated continuous current, or the transformer terminal rated current, with the appropriate safety factors applied. For example, a circuit between a 3000A breaker and a 2500A transformer terminal rating should be rated at 3000A.

    If there are multiple ratings for the equipment, use the highest rating.

    If there are known plans for equipment expansion, it may be more economical to specify a system that can carry the largest final load levels. This is because material and installation costs escalate over time and a multiple-stage installation may require demolition work.

  2. Review the environmental conditions and the area where the circuit is to be installed.
    The standard design ambient temperature for cable bus is 40°C (104°F), and ambient temperatures other than 40°C will have rating adjustment factors applied. The standard operating temperature for the cable bus conductors is 90°C, and if a different operating temperature is desired such as 75°C, rating adjustment factors are applied.

  3. If possible, review the routing drawings or site dimensions.
    The length of the circuit may necessitate rating adjustments to meet voltage drop or cable pulling length limitations.

  4. Review the specifications or requirements for the electrical equipment.
    Cable bus systems will use power cables as specified by our clients, and we can help with cable selection for cases with no established specifications.

  5. Installation considerations:
    Is the area suitable for installation of a ventilated system?
    Are there toxic chemicals present at the installation site?

    Presence of some materials in the air may require special surface treatments such as anodizing the aluminum enclosures for installations near salt water.
    Are there tight corner turns or long vertical lengths over 30-40 feet?

    Certain installation considerations may require special types or cables or special installation accessories.