Frequently Asked Questions

General FAQ's

How is a PDU Cable made?

A PDU Cable is made out of a liquid tight conduit intended for underneath raised floor environments. On one end of the cable a tail, or exposed wire, (standard tail is 8’ but can be made to any customer specified length) will be used to go up and connect into the PDU. On the other end of the cable is the receptacle, this is the end of the cable that supplies the power to the different types of machines. Each piece of equipment will have different power needs and require a special receptacle type to accommodate its outlet; these factors determine the number and size of wires used to build the actual PDU Cable.

How are PDU Cables packaged?

PDU Cables power cable assemblies are coiled into sturdy fiber drums, from shortest to longest cable length and barreled by PDU designation, panel and row (or any other customer provided specification) for ease of in-row installation. Cables are wiped clean prior to barreling to ensure cleanliness and minimize the introduction of contaminants into the data center. Each drum is labeled with a sheet that identifies exact contents and showing Hi-Pot test results, and loaded onto a standard shipping pallet. The fiber drums provide cable protection during shipment and make it easy to unload and move cables around the job site.

What if I need cables right away?

PDU Cables is known for its quick turnaround and prompt delivery; most orders can be built and shipped within 24 hours. Expedited orders and shipping are available as well. Our quick turn philosophy, with attention to detail, has helped many data center professionals meet tight deadlines.

If wiring to a tall RPP unit, can PDU Cables provide tails to fit?

Yes, our standard cable tails are cut to an 8’ length, but longer tails are available when wiring to tall RPP units or connecting to a cable trough.

What different mounting options does PDU Cables offer with its cables?

PDU Cables offers a variety of options to facilitate elevated mounting positions including pedestal clamps attached to the back of the box, mounting bolts through the back of the box for the receptacle to be attached to the uni-strut, and mounting ears.

Mount power receptacles closer to the plug and off the floor to help protect against possible pooling water and address cable air dams under the raised floor. Elevated mounting positions allow for better airflow and improved CRAC unit (computer room air conditioning) efficiency.

Why does PDU Cables offer circuit breakers?

With each cable purchase PDU Cables can provide a circuit breaker matched to the cable and your main breaker, giving you one less thing to worry about. PDU Cables stocks a full line of both plug-in and bolt-in style circuit breakers, including Square D, GE and Cutler-Hammer.

Can PDU Cables help configure my cables?

Our cable technicians provide project take-off, panel schedules, schematics and labeling services. If you have engineering or architectural drawings, we can create a list of cable requirements for a quote as part of a take-off process.

Does PDU Cables offer a warranty?

PDU Cables ensures that all power cable assemblies are free from defects in quality and workmanship from the date of original purchase. PDU Cables warranty excludes connectors, circuit breakers, and devices and does not cover damages due to accidents, abuse or improper installation. Contact your regional sales manager for more information about registering for the limited lifetime warranty.

Are custom fixture whip options available?

Yes. We can produce custom lengths, wire gauges, and connector configurations to meet project-specific requirements.

What Are Circuit Breakers?

A circuit breaker is an automatic switch that protects a circuit from damage caused by overcurrent, overload, or a short circuit.

When functioning normally, a breaker conducts the current as efficiently as possible. And when it trips, it isolates the fault before it can cause damage to equipment downstream.

Why Do Circuit Breakers Fail?

Most people don’t think about circuit breakers until one of them fails at the worst possible moment. The most common reason isn’t faulty devices. It’s lubrication.

Lubrication is applied during manufacturing, but if your circuit breakers have been sitting around for months or years, the grease can dry out or degrade over time. Breakers can also fail because of faulty components, corrosion, debris, or out-of-tolerance parts.

Branch Circuit Power Whips FAQ's

What is a PDU Cable?

A PDU Cable, branch circuit power distribution cable or “power whip” is a cable that carries power from a Power Distribution Unit (PDU) or Remote Power Panel (RPP) underneath a raised floor, or overhead to power up equipment, typically computer equipment like servers.

What Are Power Distribution Cables?

PDU Cables power distribution cable assemblies (also known as power whips) are designed specifically for data centers and other mission-critical environments. These cables serve as the connection between a Power Distribution Unit (PDU) or Remote Power Panel (RPP) and the rack-mounted power distribution units that supply power to servers.

In a typical data center, power is distributed from an overhead or underfloor PDU to equipment racks through branch circuit power cables. Servers connect to rack-mounted PDUs, which in turn connect to the power distribution cables, completing the power circuit. For redundancy and failover protection, most server racks are supplied by two independent power cables.

Each cable is custom manufactured to meet the exact specifications of the data center and the equipment it powers. Voltage, amperage, connector types, and cable lengths vary based on application requirements. To support efficient installation and maintenance, cables are labeled with identifying information such as power source, destination, and component details.

Power distribution cables may be fabricated on-site by electricians, built by electrical contractors, or purchased as pre-manufactured assemblies. Since 1981, PDU Cables has specialized in manufacturing high-quality, UL-listed power distribution cable assemblies for data centers across North America.

Every cable is built using premium components, tested prior to shipment, and manufactured according to strict quality-control procedures. Our experienced team and proven processes ensure reliable performance, fast turnaround times, and consistent results.

Why Test Power Cable Assemblies?

Power cable assemblies are tested because testing is required for UL Listing, helps eliminate the possibility of power cable failure at startup, ensures power cable performance under load, guarantees the power cable is free of manufacturing or component defects, and documents test results as part of power cable process controls.

Why Do UL-Listed Power Cables Matter?

Building a fault-tolerant critical power system requires more than redundancy. It demands safe, reliable products that meet the strict standards of mission-critical environments.

The UL Listing Mark on every PDU Cables assembly certifies that the cable meets the safety and performance standards established by Underwriters Laboratories. These standards are also recognized by NFPA 75 and NEC Article 645.5, which address the use of UL-listed power cables in Information Technology Equipment (ITE) rooms.

Why Use UL Listed Power Cables?

Underwriters Laboratory (UL) is the standard for safety and compliance. Underwriters Laboratory identifies a product that is certified for conformity and tested for quality.

The UL Listing certifies that PDU Cables equipment, materials, and processes meet the standards and safety requirements needed to provide assurance that its branch circuit power whips are safe for data center use.

The UL Listing Mark is one of the most recognized, accepted, and trusted symbols in the world. It means that a not-for-profit, independent laboratory has tested samples of products to safety requirements and conducts periodic checks of manufacturers' facilities. It is your assurance that steps have been taken in the interest of safety.

Safety, quality, efficiency, reduced costs, and consumer confidence are some of the other benefits of UL certification.

The UL Listing is proof that you are getting the best value for your money.

How are PDU Cables tested?

ALL (100%) of PDU Cables power distribution cable assemblies are thoroughly factory-inspected and tested to ensure unsurpassed performance and reliability.

Insulation Leakage Test

PDU Cables performs insulation testing on all of its power cable assemblies. The test ensures minimal leakage through wire sheathing and verifies that the conductors were not damaged during assembly which can create arching between conductors or to ground, causing a circuit to trip. This also tests for proper phase rotation to ensure all conductors are connected to the proper terminations.

Phase Rotation Test

In addition to the tests required by Underwriters Laboratory, PDU Cables performs an additional continuity test on each conductor to ensure each device is wired properly. This tests continuity between each blade or socket of the supplied plug or receptacle and the correct color conductor at the opposing end of the cable, ensuring the device is wired according to the correct color code.

Ground Continuity Test

This test ensures that there is grounding continuity between the grounding blade or socket of the supplied plug or receptacle and the supplied grounding conductor on the opposing end of the cable. The continuity testing ensures that there are no breaks in the conductors used.

Dielectric Withstand Voltage Test (Hi-Pot)

The Hi-Pot test is performed on each conductor at 60hertz, 1200 volts (AC) + 2.4 times the marked voltage for one second. For instance, if the cable is for a 120 volt application, the voltage amount applied to the cable would be 1200 + 288 (2.4 x 120 volts) or 1488 volts applied at 60 hertz for one second. There can be no breakdown (shorting or arcing) of any conductor during the test.

Why Test Circuit Breakers?

If a circuit breaker fails during an overcurrent event, losing power isn’t the only concern. It can lead to overheating, equipment damage, fire risk, and potential injuries to anyone working in the facility.

The best way to avoid this? Don’t put circuit breakers into service unless you’re certain of their condition. Whether they’re new or old, testing your breakers is one of the best ways to protect a facility worth millions.

What is the benefit in labeling the cables?

Each PDU cable includes a cable identification label which references the circuit number, equipment, PDU panel, receptacle and length, as well as the UL certification. This allows for easier installation when on site and for quicker isolation of cables if you need to shut equipment down.

Individual labels are protected with clear heat shrink wrap tubing to prevent alteration or accidental removal, and are located at both ends of the cable (or located per customer specification for convenient identification).

What types of cable options does PDU Cables provide?

PDU Cables offers power cable assemblies for both under-floor and drop-down power solutions, including:

Liquid-Tight Flexible Metal Conduit (LFMC)
Flexible Metal Conduit (Greenfield - RWA or RWS)
SO Cord Assemblies
Metal Clad (MC) Cables
Tray Cable (STOOW)
Molded Cord Assemblies

Where are PDU Cables used?

A PDU Cable can be found in almost any environment that has a raised floor. Data centers, telecom offices, hospitals, laboratories. Thousands of data centers, including many Fortune 500 Companies, financial institutions, schools and universities, manufacturing and industrial facilities, and government organizations have made PDU Cables their first choice for power whips.

Can PDU Cables provide Multiple Circuit Cables or Daisy Chains?

Yes, space under the data center floor is always difficult to allocate and manage. When you consider the number of “line-powered” devices to be provisioned, you should also consider installing multiple circuit cables (MCC’s). Multiple circuits can be run through the same cable conduit allowing for 2, 3 or more pieces of equipment to be powered off the same power whip, saving you time and money. Our cable technicians can help you decide when and where daisy chains or multiple circuit cables make sense.

Busway Tap-Off Boxes FAQ's

What is a power distribution tap-off box?

A power distribution tap-off box connects to an overhead busway system and provides a convenient way to distribute power to equipment below. It contains the required breakers, wiring devices, and receptacles to safely deliver power from the busway to connected loads.

Which busway systems are these tap-off boxes compatible with?

Busway Solutions tap-off boxes are designed for use with Starline T5 Series busway systems, including B250, B400, and B800 models.

What are the advantages of choosing a Busway Solutions tap-off box?

Busway Solutions tap-off boxes provide a cost-effective alternative to OEM options while offering custom configurations, quick-turn production, simplified installation, certified performance, and reliable power distribution for data center applications.

Can tap-off boxes be customized?

Yes. Each tap-off box is custom built to your application and can be configured with customer-specified circuit breakers, receptacles, wiring devices, and drop cord arrangements to meet specific power requirements.

Are drop cords available with tap-off boxes?

Yes. Tap-off boxes can be configured with single or multiple drop cords and are available in a wide range of lengths, cord types, and connector configurations to support your installation requirements.

Are the tap-off boxes pretested before shipment?

Yes. Every tap-off box is 100% pretested prior to shipment and is provided as a ready-to-connect assembly to help simplify installation and reduce startup time.

Are the tap-off boxes certified?

Yes. Busway Solutions tap-off boxes are ETL certified and compliant with UL 857 standards for branch circuit busway systems.

What are the advantages of choosing a Busway Solutions tap-off box?

Busway Solutions tap-off boxes provide a cost-effective alternative to OEM options while offering custom configurations, quick-turn production, simplified installation, certified performance, and reliable power distribution for data center applications.

How do tap-off boxes help reduce installation time?

Each unit ships as a fully assembled, pretested solution with the specified breakers, receptacles, wiring devices, and drop cords already integrated. This reduces field wiring requirements and helps accelerate deployment.

Floor Grommets FAQ's

Which is better, brush grommets or “rubber” gasket grommets?

While both the brush grommets and EPDM “rubber” gasket grommets perform exceptionally well in preventing air flow bypass, the most energy efficient grommet incorporates both the brush and rubber gasket technologies, these are the Extreme, 5" Round and Brat units. While the Extreme is a top choice for new construction where a larger opening is desired, the 5" round is popular where only data cables or power cables are being pulled through a cable cutout. Filling holes in floors with cables already pulled, might be best left to the Brat, Flush Mount or Surface Mount units.

How do grommets protect computer equipment?

The overlapping brushes prevent passage of debris and contaminates from entering the air plenum system and causing damage to sensitive electronic equipment.

Why Does Picking The Right Data Center Floor Grommets Matter?

Every cable running through a raised floor leaves an opening. Each opening is a path for cold air to escape into the underfloor plenum rather than reach the servers that depend on it. As a result, your cooling system works harder, your energy bills climb, and your equipment runs hotter than it should.

AirGuard raised floor grommets seal those openings. Think of a cable seal as a low-cost insurance policy against tens of thousands of dollars in potential damage from servers overheating.

What Are The Benefits of using Data Center Floor Grommets?

Reduce bypass airflow and improve static pressure under the floor.
Protect sensitive AI hardware by reducing particulates in underfloor air.
Extend the life of cooling equipment by reducing workload.

What Certifications Do PDU Cables AirGuard Floor Grommets Have?

UL 94 V-0 rated for flammability
Meets NFPA 75 and NEC 645.5 standards
U.S. Department of Energy recommended best practice
RoHS compliant

How does AirGuard help Data Center’s save money?

Data centers are energy intensive, consuming up to 40 times the energy of a conventional office building. A significant portion of any data center’s energy consumption is in the CRAC (computer room air conditioning) units. Yet it has been estimated that only 40% of a cooling systems cold air goes directly to cool servers. A key problem affecting air management is when cooled air circulates back to air conditioning units through openings in raised floors such as cable openings or misplaced floor tiles with openings.

How effective are AirGuard at eliminating bypass airflow?

Research has shown that AirGuard Cable Seal grommets reduce bypass airflow by as much as 96% compared to a typical “open hole”. The addition of the AirGuard Cable Seal grommets resulted in a reduced overall temperature of an operating data center by 8 degrees Celsius (nearly 15 degrees Fahrenheit).

A well designed air distribution system can reduce energy consumption, reduce investment in CRAC equipment, allow for increased equipment utilization, and improve reliability by reducing processing interruptions or equipment failure due to overheating.

Are AirGuard safety covers important?

The safety cover removes any worry about accidental injury when grommets are installed but left unattended.

Why are AirGuards constructed of ABS polycarbonate material?

The ABS polycarbonate construction of the AirGuard and safety covers is flame retardant and provides a safe continuous slip resistant solid surface when cables are not pulled through openings. NFPA 75 5.4.2 requires that flooring material in a raised floor data center meet NASI/UL 723 flame srpead index of 25 or less. AirGuard's UL 94 VO rated construction meets the NFPA 75 standard.

What are the benefits of the removable brushes in the AirGuard Flush Mount and Brat?

The removable brush feature allows for easy removal of floor panels without disconnecting cables. This feature also allows larger connectors to pass through the grommet without the need for an oversized cutout.

Does AirGuard come with installation instructions and mounting hardware?

Yes, each AirGuard Cable Seal grommet comes complete with mounting hardware and installation instructions for quick and easy installation.

Does AirGuard offer a warranty?

PDU Cables, Inc. provides a lifetime warranty for all Air-Guard products purchased through PDU Cables, and warrants that each product is free from defects in quality and workmanship from the date of original pruchase. If any AirGuard product should fail because of a manufacturing defect, PDU Cables will repair or replace the product free of charge, provided that the product has not been subjected to abuse, misuse, accident, disaster or non-authorized modification or repair.

For more information contact your regional sales manager.

What Certifications Do PDU Cables AirGuard Floor Grommets Have?

UL 94 V-0 rated for flammability
Meets NFPA 75 and NEC 645.5 standards
U.S. Department of Energy recommended best practice
RoHS compliant

I need a retrofit solution for odd shaped and sized cutouts.

The best retrofit solution for odd shaped and sized cutouts is the AirGuard Surface Mount. Its two piece construction allows for a quick retrofit around existing cables without the need to disconnect cables. Simply remove the adhesive tape from the underside of the Surface Mount, position the two sides around the existing cables, and press in place and finish with the included mounting screws.

Ground Bonding FAQ's

What is the difference between grounding and bonding?

Grounding provides a path for electrical current to dissipate safely, while bonding electrically connects conductive components together. Both are essential for protecting equipment, maintaining system reliability, and supporting a complete grounding system.

What standards govern data center grounding and bonding?

Data centers commonly reference TIA-942 for data center infrastructure and TIA-607 for telecommunications grounding and bonding. These standards provide guidance for designing structured grounding and bonding systems that support reliable operation.

What is telecommunications bonding?

Telecommunications bonding connects racks, cabinets, cable trays, busbars, and equipment to a common grounding network. Bonding helps maintain equal electrical potential throughout the data center and reduces the risk of electrical disturbances affecting equipment performance.

What is a common bonding network?

A common bonding network is a grounding infrastructure that connects racks, cabinets, busbars, cable trays, and equipment to a shared electrical reference point. This helps maintain consistent electrical potential throughout the facility.

What is a rack bonding busbar?

A rack bonding busbar is mounted within a rack or cabinet and serves as a common grounding point for rack-mounted equipment. It allows multiple devices to be bonded directly to the grounding network.

What is a unit bonding conductor?

A unit bonding conductor connects individual devices, such as servers, switches, routers, and patch panels, directly to a rack bonding busbar. This provides each piece of equipment with a direct grounding path.

What is a telecommunications equipment bonding conductor (TEBC)?

A TEBC is used to bond telecommunications equipment, racks, or cabinets to the facility grounding system. It helps create a complete grounding and bonding network throughout the data center.

Why is direct bonding preferred over daisy-chaining?

Direct bonding provides a shorter and more reliable path to the grounding network. This approach helps maintain electrical continuity and minimizes the potential for voltage differences between connected components.

What equipment should be included in a grounding and bonding system?

Commonly bonded infrastructure includes racks, cabinets, busbars, cable trays, ladder racks, patch panels, servers, switches, routers, surge protection devices, and other metallic telecommunications equipment.

How do grounding busbars and bonding conductors work together?

Grounding busbars provide centralized connection points, while bonding conductors create the electrical connections between equipment, racks, cabinets, and the grounding network. Together, they form a complete grounding and bonding solution.

Can grounding and bonding products be customized?

Many grounding and bonding products are available with custom lengths, lug configurations, hole spacing, mounting options, and termination styles to accommodate specific installation requirements.

Why choose SurgGuard grounding and bonding products?

SurgGuard grounding and bonding products are designed to help create a structured grounding network for data centers and telecommunications environments. The product line includes grounding busbars, bonding conductors, and accessories that support equipment protection, reliability, and simplified installation.

Do I need both busbars and bonding conductors?

In most applications, yes. Busbars provide centralized grounding points, while bonding conductors connect racks, cabinets, and equipment to the grounding network. Using both creates a more complete grounding and bonding system.

What is a rack bonding conductor?

A rack bonding conductor creates a connection between a rack or cabinet and a grounding busbar or grounding network. It helps establish a reliable grounding path and supports proper rack bonding practices.

Temporary Power FAQ's

Is the Temporary Power Block weatherproof?

Yes. It is NEMA 3R rated, meaning it is weather-resistant and built for both indoor and outdoor job site conditions.

Can I charge my phone or tablet with the Temporary Power Block?

Yes. The Temporary Power Block includes USB Type A & C charging ports, so you can power mobile devices and tablets directly from the unit.

What type of connectors does the Temporary Power Block use?

The Temporary Power Block uses California-style CS 50A twist-lock input and output connectors for secure and reliable connections on the job site.

Temporary Lighting FAQ's

What makes the TIGRESS Prefab Temporary LED Light Fixture different from the other job site lights?

The TIGRESS is designed for fast installation and flexibility. It includes tool-free level nut connectors, daisy-chain capability, and compatibility with multiple cable types, making it easier to deploy across any job site compared to standard temporary lights.

What types of wiring or cables can be used with the TIGRESS fixture?

The TIGRESS Prefab Light Fixture is compatible with Junior Service Cord, NM-B cable, MC cable, and FMC whips when used with a suitable connector, offering maximum flexibility on the job site.

What makes the TIGRESS Prefab Temporary LED Light Fixture different from the other job site lights?

The TIGRESS is designed for fast installation and flexibility. It includes tool-free level nut connectors, daisy-chain capability, and compatibility with multiple cable types, making it easier to deploy across any job site compared to standard temporary lights.

Can multiple TIGRESS fixtures be connected together?

Absolutely. The fixture is daisy-chainable, allowing contractors to connect multiple units for broad, continuous light coverage across large work zones.

What type of power connections does the TIGER XL use?

The luminaire features a 1-foot pre-stripped pigtail for hard-wiring into a 120V or 277V circuit, plus a 35-foot connectivity cord for powering multiple fixtures.

Can multiple TIGER XL Luminaires be linked together?

Yes. Up to four units can be connected on a 120V circuit and up to seven units on a 277V circuit using the 35-foot connectivity cord.

What type of power connections does the TIGER XL use?

The luminaire features a 1-foot pre-stripped pigtail for hard-wiring into a 120V or 277V circuit, plus a 35-foot connectivity cord for powering multiple fixtures.

Does the TIGER XL require maintenance?

No. The LEDs are long-lasting and maintenance-free, eliminating lamp replacements and reducing labor costs.

Grounding Products FAQ's

If wiring to a tall RPP unit, can PDU Cables provide tails to fit?

Yes, our standard cable tails are cut to an 8’ length, but longer tails are available when wiring to tall RPP units or connecting to a cable trough.

What wire size is used for EPCO Grounding PigTails and PowerTails?

These pigtails use 12 AWG insulated stranded copper wire, unless otherwise noted.

Where can these pigtails be used?

Ideal for power distribution boxes, junction boxes, and multi-gang receptacle boxes in commercial, residential, and industrial products.

What wire size is used for EPCO Grounding PigTails and PowerTails?

These pigtails use 12 AWG insulated stranded copper wire, unless otherwise noted.

Where can PowerTails be used?

Perfect for single and multi-gang metallic boxes in commercial, residential, and industrial projects.

Prefabricated Whips

Are custom fixture whip options available?

Yes. We can produce custom lengths, wire gauges, and connector configurations to meet project-specific requirements.

What connector options are available with the EPCO Fixture Whips?

EPCO offers multiple external connector options:
- External Die-Cast Snap-In Connector with Set Screw
- External Phenolic Snap-In Connector Die-Cast Type Connector with Set Screw
- External Lock Nut. Custom color configurations are also available.

What is the EPCO Illumination Control Fixture Whip (ICFW) used for?

The ICFW is a pre-fabricated solution for illumination and lighting control, designed for LED and fluorescent systems in commercial, industrial, and institutional buildings. It supports daylight harvesting, occupancy sensors, and timed lighting schedules.

What voltage systems is the EPCO Illumination Control Fixture whip compatible with?

This whip is compatible with 120V and 277V LED lighting systems.

What type of conductors are included with EPCO Illumination Control Fixture Whips?

Each whip includes two 18 AWG, 300-volt rated conductors, color-coded
purple and pink for easy identification.

How does the ICFW fixture whip differ from EPCO's standard fixture whip?

The standard whip only connects line voltage conductors (Class 1). The ICFW includes low-voltage
conductors for dimmable ballasts, LED drivers, and wireless lighting controls,
enabling a single pre-fabricated whip for smart building applications.

Can the EPCO fixtures whip be used for retrofit or new construction projects?

Yes. It is ideal for both new LED installations and retrofit smart lighting systems in commercial, industrial, or institutional buildings.

Do wireless lighting controls require a special fixture whip, and if so, why?

- Wireless Lighting Controls use Relay Modules that can be attached to the outside of an electrical junction box with a nipple.
- The connection(s) of the low voltage conductors from the dimmable ballast or LED driver are intended to go through the Junction Box, and through the nipple and into the Lighting Control Relay Module to receive controller commands.
- When the Electrical Contractor wants to use a single pre-fabricated Fixture Whip to control a luminaire with control features.

Are custom fixture whip options available?

Yes. We can produce custom lengths, wire gauges, and connector configurations to meet project-specific requirements.

What is the EPCO Stranded Wire 3/8" Die Cast Screw-In Fixture Whip used for?

This fixture whip is designed for commercial, industrial, and institutional lighting installations in the U.S., providing a pre-assembled, UL-listed solution for efficient, reliable, and code-compliant wiring.