Views: 0 Author: Site Editor Publish Time: 2026-08-18 Origin: Site
Since you have specified power entry modules, it will be safe to assume you understand the terms "inlet" and "outlet." The problem is that these terms can sometimes be confused with each other. Confusion between the IEC inlet and IEC outlet causes incorrect connector orientation, noncompliance check failures, and rework in a running production line.
In this article, you will learn the difference between IEC inlet and IEC outlet in regard to their purposes, IEC 60320 numbering, pairing, and how to pick the correct connector for your appliance.
IEC 60320 is an international standard issued by the International Electrotechnical Commission, defining non-locking appliance couplers used for the connection of equipment to AC mains supply. This standard exists to ensure that a cord produced in one country will fit an appliance produced in another if both use the same connector class and amperage rating.
The standard is applicable to a series of connectors defined by a "C" number (C13, C14, C19, C20, and others). Each of those shapes is meant for particular current and temperature ratings to prevent a low-current connector from being forced into use where it was not intended.
You'll find IEC 60320 connectors in:
Industrial and lab equipment: power supplies, test instruments, and control panels that need a detachable cord.
IT and data center hardware: servers, switches, and power distribution units (PDUs) that daisy-chain power between racks.
Medical devices: where certified, non-locking connectors are required for safe cord replacement.
Household and commercial appliances: anything from kettles to office equipment.
The IEC inlet is the port on a device that connects to the external power source, generally via a removable mains cord. This is essentially the input point for the power: mains power enters the device via this inlet.
Physical structure: IEC inlets come with male contacts. They are panel-mounting connectors, found on the back/side of an enclosure, and are meant to connect to a female cord connector externally.
Placement: The inlet is always a component of the device receiving power from it and never found on the cord or the power supply device itself.
Common types you'll encounter:
C14 inlet: Capacity of 10 A at 250 V; very common on desktop PCs, monitors, and portable measuring devices.
C20 inlet: Capacity of 16 A at 250 V; common on servers, PDUs, and other devices with high current draw.
"Fused," "switched," and "filtered" variants: Many brands incorporate a fuse holder, rocker switch, or EMI filter within the same inlet module.
If you're speccing the power entry point on a new enclosure design, the inlet is what goes on your bill of materials, not the outlet.
The IEC outlet is where the power is being carried from one cord or device to another. It is the "out" part of the path—where the power moves from the outlet to whatever it is connected to.
Physical design: The IEC outlet is always a female type of the connection. In other words, it is a receptacle where we can connect a male connector: either a power cord plug or an interconnect cable going to a downstream device.
Where they sit: The outlets can be found on power distribution units, on UPSs, and generally on all devices whose function is to pass power to another device.
Common types you'll encounter:
C13 outlet: rated for 10A 250V and is what we connect our standard computer power cords to.
C15 outlet: same rating as C13 but has a notch, making it more tolerant to high operating temperatures (for use near heat-generating devices such as some laser printers).
C19 outlet: rated for 16A 250V, standard in server class PDUs and rack power strips.
C21 outlet: a high-temperature version of the C19 outlet.
If your equipment is passing power onward to another cord or device, rather than pulling it from the mains, you're specifying an outlet.
Attribute | IEC Inlet | IEC Outlet |
Power direction: | Power flows in, from the mains cord to the device. | Power flows out from the device to a downstream cord. |
Gender: | Male pins | Female receptacle |
Common designations: | C14, C16, C18, C20, C22 | C13, C15, C17, C19, C21 |
Typical location: | Rear or side panel of the powered equipment | PDU, UPS, or any device redistributing power |
Common accessories: | Fuse holders, rocker switches, EMI filters | Rarely combined with switching; mainly a pass-through socket |
Connectors are designed in matched pairs. An inlet and its corresponding outlet share compatible pin geometry but serve opposite roles in the circuit:
C13/C14 pair: 10 A, 250 V, max 70°C. This combination has a huge market presence across the world, as it is used in desktop computers, monitors, and light industrial machinery.
C15 / C16 pair: 10 A, 250 V, max 120°C. Used in equipment that operates at higher temperatures, like some kitchen appliances and IT equipment located close to heat sources.
C19/C20 pair: 16 A, 250 V, max 70°C. An upgrade to C13/C14, which is used in servers, high-current PDUs, and rack-mounted UPS systems.
C21 / C22 pair: 16 A, 250 V, max 155°C. A higher temperature combination of cords is used in special industrial and heat proximity applications.
Mixing up the pairing combination is no trivial matter. Although a C13 cord will physically fit in a C14 inlet and not fit properly on a C20 inlet, trying to plug a lower-rated connector in a higher-current application is a fire hazard and not just a fit issue. This is exactly the reason the current rating and temperature class should be nailed down before your bill of materials is final.
If you're staring at a piece of equipment or a datasheet and need to confirm which connector you're looking at, a few checks settle it quickly:
Check the pins, not the label: Male pins on the panel identify an inlet, while a female socket signifies an outlet. The term "socket" is often used interchangeably in the datasheets of some manufacturers even though technically, both inlets and outlets qualify as sockets.
Trace the power direction: Ask about the end of the mains cable that is inserted into the equipment to determine whether you have an inlet or an outlet.
Look up the C-number: Compare the C-code number of the connector against the list of IEC 60320 connectors and determine whether the number is even (inlets) or odd (outlets).
Read the current and temperature rating on the housing: All molded connectors will carry the rating, which also determines the pair family of the connector.
One common pitfall to watch out for here is that some suppliers use "sockets" to describe the entire range of their products. This terminology is technically correct (since all inlets and outlets are sockets) but useless when you try to order a specific type. Make sure to double-check the gender and C-code of your part prior to adding it to your bill of materials (BOM).
The OEM design often includes more than just a passive port as the inlet. Many OEM designs require a power entry module (PEM), which is an enclosure combining the IEC inlet, switch, fuse block, and circuit breaker into one component.
Why this matters for your design:
Space savings: One hole in your enclosure does everything that was previously done by three different holes in your enclosure.
Compliance simplification: Using a certified inlet with a certified circuit breaker in the same module reduces the number of separate certifications required by UL, VDE, or CQC.
Cleaner internal wiring: Fewer discrete components mean shorter wire runs and fewer connection points where a fault could develop.
This is where inlet selection overlaps directly with breaker and isolator selection. Our CVP-CHB1 IEC series miniature circuit breakers are built for exactly this kind of integration pairing with IEC inlet housings to deliver overcurrent protection at the point of power entry. For equipment that needs a manual disconnect rather than trip protection, our CRS1 series isolator switches serve the same design philosophy: put the safety function where the power enters, not buried deeper in the enclosure.
If you're speccing a new power entry module, it's worth evaluating the inlet, switch, and breaker together as a system rather than sourcing each part independently. Mismatched current ratings between an inlet and its paired breaker is a more common design error than it should be.
A handful of factors should drive your selection, in this order:
Current rating: The connector should match the current draw of your equipment, taking margin into account. An item that draws nearly 10 A should not be drawing from a C14 connector with the same maximum rating.
Voltage rating: Ensure that the connector is suitable for the mains voltage in your intended market.
Ambient temperature: In case your connector is near a heat source, such as a power supply or transformer, upgrade to a C15/C16 or C21/C22 combination instead of overstressing the regular C13/C14 connector.
Certification requirements: Different export markets will require a different certification agency. Check your connector for the required certification, depending on your intended market. For instance, the certifications required by North America include UL, whereas those for Europe include VDE or ENEC, among others, and China requires CQC and CCC.
Mounting style: The panel mount and chassis mount connectors differ in footprint and screw type. Check your connector's compatibility against your enclosure drawings before making tooling decisions.
Integrated protection: It is important to decide on whether you will require an inlet together with an external breaker or a combined one early in the process. This decision affects panel layout more than most engineers expect.
Our full socket product line covers both inlet series (CSK-A15 and CSK-A20) and outlet series (CSK-B15 and CSK-B20), each available in fused, switched, and standard configurations to match these criteria.
Even experienced procurement teams run into a short list of recurring issues:
Mismatched connector pairs: Ordering a C13 connector while having a C20 inlet, or vice versa, and assuming any "IEC connector" will do. Pin layout between the connector pairs is not interchangeable, and forcefully connecting them results in damage to both parts.
Ignoring temperature class: Selecting a standard C13/C14 connector pair in a high-temperature application and experiencing a thermal breakdown only months after installation.
Overlooking export certification: Selecting a connector with an approval for one geographic location and shipping equipment to another without verifying the compliance with the electrical code in the destination country.
Skipping the breaker/inlet current match: Placing an inlet with a 16 A capacity after a 10 A breaker and vice versa, thus under-protecting the circuit or causing false trips.
Catching these at the design review stage costs a few minutes. Catching them after tooling is cut costs a production run.
Understanding the difference between IEC inlet and IEC outlet will help avoid future problems in the form of unnecessary rework, failure to comply, and inconsistent Bill Of Materials (BOM). Chinehow produces the entire line of IEC inlets and outlets, together with miniature circuit breakers and isolator switches to be used with them, thus making the whole system available as a complete solution instead of separate components.
Contact our team, and we'll help you match the right connector series to your application.
Certainly not—you cannot use an IEC outlet (female socket/receptacle) for an inlet (male appliance coupler) on a device because it would have exposed live electrical pins after disconnection, posing a serious danger of an electric shock.
The main difference between C13 and C14 connectors is their gender and function: the C13 is a female socket usually found at the end of a power cord, while the C14 is a male inlet built directly into a device or power unit.
Some IEC inlets come with built-in fuses or switches, while others are simple, basic sockets.
You need an IEC C19 (female cord connector) and C20 (male appliance inlet) pair for high-current equipment.
