International Appliance Manufacturing 2008 - (Page 71) These plugs are used in high-powered applications where it is critical for products to remain locked. Photo: Quail The ends of these hospital grade plugs are clear to make sure the connections are secure and in the correct location. Plugs can be lit as an option to make them easier to locate and to ensure that power is still flowing to the outlet. Photo: Quail tally pulled from an outlet. Because there are many applications where a disruption of power is critical, such as in medical or computer environments, locking plugs can be crucial. Traditional locking plugs have blade configurations that allow the plug to be inserted into the socket and twist locked into a twist-lock receptacle. Twist locks come in a variety of maximum voltage and current capacities. For example, Conductive Cable, Rancho Santa Margarita, Calif., has six versions of its twist locks. The plugs, in the company’s CP line, include: 125V and 15A or 20A; 250V and 15A or 20A; and, 277V and 15A or 20A. These plugs are notated by an L in front of the model numbers, such as the L5-15P that is a locking plug rated at 15 A at 125 VAC. These plugs come assembled and in disassembled packages. Greg Ruppert says that plugs that need to be assembled have the possibility that they can be put together incorrectly and can come loose or disconnected inside of the plug. Instead, Quail offers molded versions of the heavy-duty locking plugs that are electrically tested “so that there is no chance that they can shake loose and become disconnected.” Beyond the locking blade configurations, suppliers are now offering new types of locking plugs. Quail Electronics offers the SafetyLock system, which was introduced in June 2006, which is available for low-amperage applications and higher-amperage applications such as servers and certain types of medical equipment. The system comes in two options. In one, it comes packaged on a new plug and the user only needs to put on the mounting plate and screw it into the inlet. The system is also sold separately and can be retrofitted onto previously purchased Quail cords. Another company offering a safety lock is Volex of Indianapolis, which recently introduced the V-Lock. The plug uses a locking and release button on the equipment end. The V-lock will be sold in standard kits or, depending on the run size, in lots. Because locking plugs are used in critical situations, they often undergo insertion withdrawal tests, in which a 55-lbs. weight is hung from the cord and plug. In the case of the V-lock, these tests helped ensure that it will hold up to 25 KG withdrawal force, says Steve Cloyd, Volex’s application engineer. In addition to ensuring that the plug doesn’t get prematurely withdrawn, the V-lock eliminates other locking solutions such as a bail latch, says Mary Foreman, Volex’s engineering manager. A bail latch is an add-on solution that snaps around the back of the plug. However, that hasn’t always been the answer because the connector body is not always the same size. George Adams, Volex’s national distributor sales manager, adds that designers will need to specify the inlet as well as the cord. The inlet The V-lock locks in the plug at the equipment end and helps ensure against accidental unplugging. Photo: Volex International Appliance Manufacturing 2008 71
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.