Difference Between C7 and C8 Power Cables

C7 and C8 power cables are part of the IEC 60320 standard, commonly used to connect low-power devices to a power source. Despite their similar appearance, they serve distinct roles in electrical systems. This article explores their differences through three key sections, using a table to compare their characteristics and analogies to make concepts engaging.

Table of Contents

• What Are C7 and C8 Power Cables?

• How Do C7 and C8 Power Cables Differ?

• Where Are C7 and C8 Power Cables Used?

What Are C7 and C8 Power Cables?

C7 Power Cable: The C7 is a two-pin connector, often called a "figure-8" or "shotgun" connector due to its shape, used to connect a power cord to a device’s C8 inlet. It’s rated for low-power applications, typically up to 2.5A at 250V internationally or 7A at 125V in North America, and is ungrounded, suitable for double-insulated devices.

C8 Power Inlet: The C8 is the corresponding inlet on a device, designed to accept a C7 connector. It’s also ungrounded and has a figure-8 shape with two slots, matching the C7’s pins. The C8 is typically found on the power supply or device itself, not as a cable.

Think of the C7 as a key that fits perfectly into the C8 lock, delivering power to small devices with precision, like a courier dropping off a lightweight package.

How Do C7 and C8 Power Cables Differ?

The C7 and C8 are complementary components of the same power connection system, not interchangeable cables. Below is a detailed comparison of their characteristics:

The key difference is that the C7 is the plug end of a power cord, while the C8 is the socket on a device. A non-polarized C7 has two rounded pins, while a polarized C7P has one squared pin to ensure correct orientation in polarized C8 inlets. The C8 inlet can accept both, but a polarized C7P won’t fit a non-polarized C8 if the device requires specific polarity. It’s like a USB plug (C7) and port (C8)—one delivers the connection, the other receives it, but they must match perfectly to work.

Where Are C7 and C8 Power Cables Used?

C7 and C8 connectors are used in low-power, double-insulated devices that don’t require grounding, ensuring compact and safe power delivery.

• C7 Connector: Found on power cords for devices like TVs, Blu-ray players, laptop chargers, game consoles (e.g., PlayStation 2), radios, and small appliances. For example, a 6-foot C7 power cord might connect a DVD player to a wall outlet via a NEMA 1-15P plug.
• C8 Inlet: Built into the power supplies of these devices, such as the socket on a laptop charger or a portable stereo. The C8 inlet ensures a secure connection with the C7 cord, often in tight spaces due to its small profile.

In some cases, a C7-to-C8 extension cable exists, where a C8 plug connects to a C7 socket to extend the reach of a power cord, but this is less common and typically rated for the same low current. These connectors are like the small but essential gears in a clock, quietly powering devices with minimal fuss but maximum reliability.

Conclusion

The primary difference between C7 and C8 power cables lies in their roles: the C7 is a two-pin connector on a power cord, often called a figure-8, used to plug into a device, while the C8 is the corresponding inlet on the device itself, accepting the C7. Both are ungrounded, rated for low-power applications (2.5A at 250V or 7A at 125V), and may be polarized or non-polarized. Used in devices like TVs, game consoles, and laptop chargers, they ensure compact, safe power delivery. Understanding their complementary functions helps in selecting the right cable for your device’s needs.