FAQs for Data Center Power Cords

Updated on Mar 5, 2024 by

Data center power cords are important for improvements in energy consumption, data center uptime, and service response times. Improper cabling or choice of data center power cables may wreak havoc on the whole network infrastructure. Therefore, it is important to figure out the confusing questions concerned with data center power cords for better network status. Listed below are the frequently asked questions.


FAQs on Data Center Power Cord Definition, Types, and Jackets

Q1: What is a data center power cord?

A1: Data center power cords are specialized cables used to connect servers, networking equipment, and other devices within a data center to a power source. These cords are designed to deliver electrical power safely and reliably to critical infrastructure components, ensuring uninterrupted operation of data center facilities. Overall, data center power cords are essential components of data center infrastructure, providing the necessary electrical connections to support mission-critical operations.

Q2: What types of power cords are used in a data center?

A2: Data center power cords come in different types, distinguished by factors such as connector type, voltage, amperage, and cable length. The IEC power cords and the NEMA power cords are suitable and commonly used for connecting computer and network equipment (servers, network switches) in a data rack to a power distribution unit (PDU).

The most common IEC outlet types in data centers are C13 and C19 connectors as defined by IEC 60320. The most common NEMA power connectors or plugs are NEMA 5-15P. Choosing the right type of power cord is essential to ensure compatibility and optimal performance.

data center power cord

Q3: What’s the difference between C13 and C15 power cords?

A3: While both C13 and C15 power cords feature the same three-pin connector design, the key difference lies in their temperature ratings and suitability for specific applications. C13 cords are suitable for standard operating temperatures, while C15 cords are designed to withstand higher temperatures, making them ideal for use with appliances and equipment that generate elevated heat levels.

Connector Type C13 C15
Ground Post Yes Yes
Rated Current/Voltage 10 A/250 V 10 A/250 V
Shape Characteristic No notch
A notch opposite the earth
Appliance Inlet Type C14 C16
Temperature Rating 70 ℃ 120 ℃
Applications PCs, printers, monitors, instrument amplifiers fixed-configuration switches Electric kettles, computing networking closets, server rooms, PoE switches with high-wattage power equipment

Q4: What voltage should I use? 120V, 208V, 240V, AC or DC?

A4: Since the availability of DC power delivery systems outside of telecom equipment racks is not widely supported, AC power cords are still the mainstream in data centers. Most modern information technology equipment is designed to operate at AC 100 V to 250 V to accommodate North American 120/208 V, Japanese 100/200 V, and 230 V used in the rest of the world to allow for worldwide power compatibility. Normally, AC 240V power is recommended because of many reasons. For example, a 277/480V to 240/415V step-down autotransformer is 90% smaller and less expensive than a 120/208V PDU isolation transformer, and 240V distribution yields the same power capacity with nearly half the current as 120 V.

Q5: What does the data center power cord jacket abbreviations mean?

A5: In data center power cords, the jacket abbreviations typically refer to the type of insulation material used in the outer covering of the cord. Here are some common abbreviations and their meanings:

SJ: Indicates that the jacket is made of Service Junior (SJ) type insulation, which is a general-purpose thermoplastic elastomer (TPE) material.

SJT: Stands for Service Junior Thermoplastic (SJT), which is a more durable version of SJ insulation, often used in industrial settings.

SJTO: Indicates a Service Junior Thermoplastic Oil-resistant (SJTO) jacket, suitable for environments where resistance to oils and greases is necessary.

SJO: Stands for Service Junior Oil-resistant (SJO), indicating that the cord is resistant to oil penetration.

SO: Indicates Service Oil-resistant (SO) insulation, which is suitable for outdoor use and provides resistance to oils and moisture.

SOW: Stands for Service Oil-resistant Thermoplastic (SOW), indicating a thermoplastic rubber jacket that is oil-resistant.

Q6: What's the benefit of a three-wire AC power cord?

The benefit of a three-wire AC power cord is enhanced safety and reliability in electrical connections. The third wire, known as the ground wire, provides an additional path for electrical current to safely dissipate in the event of a short circuit or electrical fault. This helps to prevent electric shock and reduces the risk of fire hazards. Additionally, the ground wire helps to stabilize the electrical system and reduce electromagnetic interference, ensuring the stable and efficient operation of electrical devices. Overall, a three-wire AC power cord offers improved protection for both the equipment and the users.

Q7: What's the difference between power cords and power extension cords?

A7: Power cords are designed for direct connection between electrical devices and power sources, featuring a male plug on one end and a female connector on the other, while power extension cords are utilized to temporarily extend the reach of outlets, offering flexibility in length and portability. While power cords provide a fixed connection for permanent or semi-permanent installations, power extension cords offer a portable solution for temporary needs, but both require proper sizing and usage to ensure safety and reliability.

power cords and power extension cords


FAQs on Using Power Extension Cords in the Data Center

Q1: Can extension cords be used in ITE rooms?

According to section 400.8(1) in NEC (National Electrical Code), flexible cords and cables including power extension cords are not permitted to be used as a substitute for permanent wiring of a data center structure. Instead of relying on extension cords, it's preferable to install additional power outlets or use power distribution units (PDUs) designed for data center environments. These solutions are safer, more reliable, and better suited to the electrical demands of ITE rooms.

Q2: Are cord sets and interconnect cables considered "fixed wiring"?

According to the National Electrical Code (NEC) 645.9(F), power cables, communications cables, connecting cables, interconnecting cables, and associated components listed for use with information technology equipment are not required to be secured in place. This means that cord sets and interconnect cables, along with their associated boxes, connectors, plugs, and receptacles, are not considered "fixed wiring" under this code.

Instead, these types of cables and components are intended for flexible, movable connections within information technology equipment setups. They may be temporarily installed or repositioned as needed, in contrast to fixed wiring, which is permanently installed within a building's structure.

Q3: Why is it dangerous to use extension cords?

A3: An extension cord essentially consists of insulated electrical wires with plugs on both ends. When excessive electrical current passes through these wires, the heat generated can melt the plastic insulation, leading to short circuits and fires. This risk is minimized when appliances are plugged directly into outlets using their factory cords, which are designed with appropriate sizes for the respective appliances, thus reducing the likelihood of overheating and potential hazards.

Q4: Are there any ways to safely use extension cords?

A5: There are five rules listed below to improve worksite safety.

  • Meet OSHA requirements: Using an AEGCP (Assured Equipment Grounding Conductor Program) and using a GFCI (Ground Fault Circuit Interrupter) are two ways to meet the OSHA requirements.

  • Keep the extension cord length within safety requirements: The extension cords should not exceed 100 feet in length. If the job requires more than a 100-foot distance, a temporary power distribution box is required.

  • Discard damaged extension cords: Although the power cord can still work, the damaged power cord is a violation of the OSHA regulations. Discard the damaged power extension cables to prevent potential electrical hazards.

  • Avoid initial installation mistakes: Do not fix extension cords to walls or ceilings using metal nails or staples because there may be possible damage to the power extension cable jacket.

  • Do not run extension cords through doorways: One should avoid laying extension cords across the room to minimize trip hazards.

Q5: Power strip vs. extension cord: which one should you use?

A6: The primary distinction between a power strip and an extension cord is their intended purpose. Power strips are designed to provide multiple outlets from a single source, allowing you to plug in multiple devices simultaneously. While extension cords are used to extend the reach of a power source to a distant appliance or device. They provide additional length and flexibility when the existing power cord of a device is not long enough to reach the desired location.

Q6: Surge protector vs extension cord, what’s the difference?

A7: A surge protector diverts any extra power surges that might come through the electrical outlets to keep equipment safe. Extension cords are crucial when you need to stretch an appliance from one location to a distant electrical outlet. While surge protectors prioritize equipment safety, extension cords facilitate device placement flexibility.

Q7: Can extension cords be used permanently in a data center?

A7: No, extension cords should not be used permanently in a data center. Data centers require reliable and safe electrical connections to power critical equipment and systems. Extension cords are not designed for permanent use and can pose serious safety risks if used as a long-term solution.

Using extension cords permanently in a data center can increase the risk of electrical hazards, such as overheating, fire, and electrical shock. Additionally, extension cords are not rated for the high demands of data center environments, where continuous and stable power supply is essential for uninterrupted operations.

To ensure safety and reliability in a data center, it is important to install proper electrical infrastructure, including sufficient outlets and power distribution units (PDUs), to accommodate the power needs of the equipment. Avoid relying on extension cords as a permanent solution and instead invest in appropriate electrical installations to support the requirements of a data center environment.

Related Articles:

Advanced Tips for Ensuring Maximum Safety with IEC Power Cords

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