Power cords used for server and PDU seem like the bridges between power supply and devices. Thus, to choose a suitable power cord for your server requirement is very important.

1. WHITE PAPER
Fiberstore (FS.COM) | Brief Introduction to Server Power Cords
Server is like a large computer group which is used to manage network resources. It requires power
supply to support working. Server power cords are the basic assemblies to achieve the connection
between servers and PDU (Power Distribution Unit). However, the designs of them vary from
country to country in terms of voltage and connector types. Thus, to determine what type of power
cord your server or system requires, you need to know the country or region in which your server or
system will reside, your server or system model, and the voltage and amperage of your power
supply. In order to regulating the use of the power cords and allowing easy selection for users, there
are some standards which are used to define the connectors. In this post, we will have a brief
introduction to server power cords.
Server Power Cord Overview
We can regard a power cord as three parts—cord, plug and receptacle. Among them, the plug and
receptacle are also called connectors collectively (will be explained in details in the next part). The
three parts of a server power cord are shown as following:
 Cord—Main section of insulated wires of varying length and of a thickness determined by its
current rating.
 Plug—Male connector for insertion into the AC outlet providing power. The physical design and
layout of the plug’s contacts meet a specific standard.
 Receptacle—Female connector that generally attaches to the equipment. The physical design
and layout of the receptacle’s contacts meet a specific standard.
Brief Introduction to
Server Power Cords

2. WHITE PAPER
Fiberstore (FS.COM) | Brief Introduction to Server Power Cords
Server Power Cord Connectors – Plug & Receptacles
There are many different types of power cord connectors used all over the world. Standards for
these connectors are often set by individual countries. In the US, the most common type of power
cords have an IEC (International Electrotechnical Commission) connector that plugs into the server
and a NEMA (National Electrical Manufacturers Association) connector that plugs into the power
source. The IEC has published international standards for alternating current interconnections
between equipment. NEMA is a US based organization that establishes a wide range of standards
for US electrical devices.
 IEC Connectors
IEC 60320 is a set of standards from the IEC specifying non-locking appliance and interconnection
couplers for connecting power supply cords to electrical appliances up
to 250 V. When equipment uses connectors that comply with this
standard, worldwide compatibility is achieved. The IEC 60320 C13 / 14
connector type is seen on almost all personal computers and monitors.
It has a rating of 10 A and the female connector end is defined as C13
while the male connector end is defined as C14. The IEC 60320 C19 /
20 connectors are rated for 16 A and have a female connector end

3. WHITE PAPER
Fiberstore (FS.COM) | Brief Introduction to Server Power Cords
called C19 and a male connector end called C20. C19 / 20 connectors are commonly used for
devices such as some servers and UPS (Uninterruptible Power Supply) systems. The most commonly
used type for Dell, HP and IBM servers is the the C13 and C14 connectors.
 NEMA Connectors
NEMA connectors are power plugs and receptacles used for alternating current mains electricity in
North America and other countries that use the standards set by the NEMA. According to different
configuration, such as the number of poles, number of wires, voltage, and whether single- or
three-phase, there is different numeral preceding the hyphen in NEMA
nomenclature. And with different rating of the device in amperes, the
numeral following the hyphen is also different. In addition, plugs and
receptacles are designated with “P” and “R” in the nomenclature. If
there is an “L” in the nomenclature, it means that the plugs and
receptacles are twist locks. For example, NEMA 5-15P is the common
125 V two-pole, three-wire plug rated 15 A. NEMA 5-15 plugs and
receptacles are the most common server power cord connector types
used in the US.
Jacket Types and Wire Gauges
When getting power cords for servers, there are various jacket types and AWG (American Wire
Gauge) choices to make. How to know which one you actually need for your server power cords?
 Jacket Types
There are many kinds of jacket types which are used in power cord design. In order to better
distinguish the different jacket types and features, a series of code letters is used to describe the
jacket, as the following shown. Each letter has its own meaning describing the material used in the
jacket, the voltage rating, the jacket’s resistance to the elements, or other factors which is defined
in the UL 62 standard and stamped on the jacket.
 S—Service Grade. This means the cord is 600V rated.
 SJ—Junior Service. Meaning 300-Volt rated.
 T—Thermoplastic. The wire is coated in PVC.
 P—Parallel. These are the types of cords where each conductor insulated separately as in a
typical lamp cord.
 O—Oil-Resistant. One “O” means the jacket is resistant to oil. Two “O”s means the jacket as well
as the insulation inside the cord are oil resistant.
 W—Weather-Resistant. Essentially, these cords are outdoor-rated. They include resistance to
wet conditions as well as UV protection.
 V—Vacuum Type. Flexible jacket originally used for vacuum cleaners, but is now found on a
wide variety of products.
In addition, different jacket type corresponds to different parameters, such as permitted wire gauge,
permitted of conductors etc. The table below shows the features of some common jacket types.

4. WHITE PAPER
Fiberstore (FS.COM) | Brief Introduction to Server Power Cords
Among them, SJT and SVT are the more common jacket types used in server power cords.
Jacket Permitted Wire Gauge Number of Conductors
SPT-1 20-18 2 or 3
SPT-2 18-14 2 or 3
SPT-3 18-10 2 or 3
NISPT-1 18-16 2 or 3
NISPT-2 18-16 2 or 3
SVT 18-16 2 or 3
SJT 18-10 2 to 6
ST 18-2 2 or more
Note: The -1, -2, and -3 behide the letters indicates the thickness of the jacket. -1 is thin, -2 is
medium and -3 is thick.
 Wire Gauges
There is a close relationship between cable length, amperage and wire gauges. See the table below,
the different amperage corresponds to different AWG. The higher the amperage rate, the larger the
number of AWG is. In addition, if the length of the cord is increased, the wire gauge will have to be
increased. Wire gauges are also related with the jacket type since different jackets can
accommodate different wire gauges and number of conductors inside the power cord.
Amperage Recommended Wire Gauge
7 A 20 AWG
10 A 18 AWG
13 A 16 AWG
15 A 14 AWG
20 A 12 AWG
Summary
Power cords used for server and PDU seem like the bridges between power supply and devices.
Thus, to choose a suitable power cord for your server requirement is very important. The standards
of plugs and receptacles specify the use of the power cords and make selection become easy. Jacket
types and wire gauge are chosen depending on the server or system model, and the voltage and

5. WHITE PAPER
Fiberstore (FS.COM) | Brief Introduction to Server Power Cords
amperage etc. In addition, different jacket colors are used for unique maintenance. Fiberstore offers
the most extensive line of IEC and NEMA server power cords. The most common IEC C13/C14 for
Dell, HP, IBM servers and NEMA 5-15P in the US are available. They come in splitter cords (supports
2 or more receptacles), angled cords and locking featured cords. The color, length, angle of cable
can be customized. For more details, please contact us via sales@fs.com.

6. WHITE PAPER
Fiberstore (FS.COM) | Brief Introduction to Server Power Cords
Contact Us
Manufacturing R & D (China)
Eastern Side, Second Floor, Science &
Technology Park, No.6, Keyuan Road,
Nanshan District, Shenzhen 518057,
China
Tel: +86 (755) 8300 3611
Fax: +86 (755) 8326 9395
Email: sales@fs.com
APAC Office (Hong Kong)
1220 Tung Chun Commercial Centre,
438-444 Shanghai Street, Kowloon,
Hong Kong
Tel: +852 81763606
Fax: +852 81763606
Email: sales@fs.com
North America (United States)
331 Andover Park East Ste330, Tukwila,
WA 98188,United States
Tel: +1-425-226-2035
Fax: +1-253-246-7881
Email: sales@fs.com
London Office (United Kingdom)
Third Floor 207 Regent Street, London,
W1B 3HH, United Kingdom
Tel: +44 2081441980
Notice: This document is for informational purposes only and does not set forth any warranty, expressed or
implied, concerning any equipment, equipment features, or service offered or to be offered by Fiberstore.
Fiberstore reserves the right to make changes to this document at any time, without notice, and assumes no
responsibility for its use. This information document describes features that may not be currently available.
Contact a Fiberstore sales team for information on feature and product availability.
Follow us
LinkedIn
Twitter
Facebook
G+
Pinterest
Youtube
Blog