Use Locking Power Cords for Stable Connections in Critical Applications

Power cords are often taken for granted until they stop working. Suppose you have a rack-mounted instrument or server, and as you slide the device out of the rack, the power cord, even with a service loop, gets tangled and pulls out of the socket. Poof, you have a dead device until you realize what happened and plug it in again. If it’s an instrument making a long-term measurement or a server for the accounting department, you are in trouble. You need a power cord that can be locked into the socket to prevent it from falling or being pulled out accidentally.

Before attempting to zip-tie the power cord to the chassis or jury-rigging a clamp, consider a more straightforward solution designed explicitly to solve the problem, such as Qualtek’s Q-Secure power cords.

The power cord

The humble power cord has a substantial level of engineering behind it, as well as a host of technical and safety standards. Let’s start with a standard power cable, such as the 312003-01 (Figure 1). This 7.5 foot (ft.) cable has a plug on one end and a receptacle on the other.

Figure 1: The 312003-01 is a standard power cable with a plug on one end and a receptacle on the other. (Image source: Qualtek)

The plug side of this 125 volt, 15 ampere (A) connector is identified as a NEMA 5-15P connector. NEMA designations are based on a two-part code where the numbers before the dash represent the connector configuration and voltage, and the numbers after the dash represent the current rating. For example, the 5 in the common NEMA 5-15 represents a grounded, three-wire connector intended to handle 125 volts, and the 15 represents 15 A. The P suffix signifies that the connector is a plug, while an R suffix would indicate a receptacle.

The receptacle side of the power cable is designated as an IEC 60320 C13 connector. The IEC 60320 standards cover power connections, including plugs and receptacles, referred to as couplers. The C13 represents a grounded, three-wire receptacle with a maximum international rating of 250 volts, 15 A, and a US rating of 125 volts, 15 A.

The locking power cord

Qualtek’s Q-Secure power cords, featuring locking C13 connectors, are designed to provide a secure connection between the power cord and the device being powered. For example, the 512002-01 (Figure 2) is a locking power cord with a length of 6 ft. and uses three 18 AWG stranded wires. It is classed as an SJTW cable, indicating it is a weather-resistant, heavy-duty power cord intended for hard service.

Figure 2: Q-Secure power cords have a locking C13 receptacle to prevent them from becoming unplugged. (Image source: Qualtek)

The Q-Secure cords feature a built-in locking mechanism that is actuated by depressing the red button until it latches. The mechanism reduces the risk of accidental disconnection, ensuring the C13 receptacle remains securely connected to the power input. The locking mechanism is rated to withstand a withdrawal force up to 35 pounds (lb). The lock is released by pushing the red button back in the direction indicated.

There are fifteen versions of the Q-Secure 512 series of power cords. They are available with a choice of 18, 16, or 14 AWG wire and with lengths of 36, 72, 96, 120, or 144 inches (in.). The maximum rated current is dependent on the wire size. 18 AWG wires are rated at 10 A, 16 AWG wires at 13 A, and 14 AWG wires at 15 A. All handle a maximum voltage of 125 volts.

Hospital-grade line cords

In addition to the 512 line of locking power cords, the Qualtek Q-Secure family includes fifteen hospital-grade line cords. Hospital-grade power cables, designed to eliminate the risk of wire-to-outer boundary shock, provide optimum grounding reliability and withstand tight radius bends without incurring damage. They are tested to the UL817 and CAN/CSA C22 standards. For example, the 533012-01 (Figure 3, left) is a six-foot-long three-conductor power cord featuring 14 AWG wire and a clear NEMA 5-15P hospital-grade plug on the supply side.

Figure 3: The 533012-01 hospital-grade locking power cord (left) uses the NEMA 5-15P hospital-grade connector on the supply side of the cord; a green dot (right) indicates hospital-grade certification. (Image source: Qualtek)

Per the standards, hospital-grade connectors are identified by an indelible green dot (Figure 3, right) with specified dimensions on the face of the connector. The locking C13 receptacle is identical to the standard locking cord.

Conclusion

Instead of using external, jury-rigged clamps, designers can use Qualtek Q-Secure power cords to provide a more stable connection between a power cord and the device being powered. A built-in locking mechanism prevents accidental disconnection, making them ideal for critical applications such as data centers, server rooms, and medical devices.