this invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings . the invention is capable of other embodiments and of being practiced or of being carried out in various ways . also , the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting . the use of “ including ,” “ comprising ,” or “ having ,” “ containing ,” “ involving ,” and variations thereof herein , is meant to encompass the items listed thereafter and equivalents thereof as well as additional items . the present disclosure is directed toward locking electrical outlet units and to power distribution unit ( pdu ) or uninterruptible power supply ( ups ) products which include locking electrical outlets , for example , electrical outlets conforming to the international electrotechnical commission ( iec ) iec - c13 or iec - c19 standards . these outlets may be used in conjunction with locking electrical cords such as those developed by volex group plc of birchwood science park , warrington , wa3 7jx , england , for example , those described in u . s . patent application publication no . 2009 / 0137142 a1 , entitled “ positive lock connector .” locking outlets and locking power cords provide a method of securing power cords without the use of bulky brackets or alternative methods of securing power cords to , for example , an electrical equipment rack power distribution source . some locking outlets are designed to be used with power cords including a locking tab , such as power cord 50 , illustrated in fig3 , 9 , and 10 . when inserted into an outlet , a locking tab 60 on the power cord 50 secures the power cord 50 to the outlet . the locking tab 60 may engage a slot or recess 70 in an outlet into which the power cord 50 is inserted to lock the power cord 50 in place in the outlet . to remove the power cord 50 , the locking tab 60 may be manually depressed . although volex locking power cords and outlets are described herein , this disclosure is not limited to volex - type power cords and outlets . other locking outlet technologies may also be utilized in conjunction with embodiments of the present disclosure . conventional locking outlet technologies often require the inclusion of a gap 40 between outlets 20 to accommodate the locking feature . this gap 40 between representative conventional locking outlets 20 is shown in fig3 . this arrangement of outlets is contrasted with conventional individual ( non - ganged ) outlet units for use with non - locking power cords which may include iec outlets arranged in a linear pattern . examples of such conventional ganged iec outlet units 10 , 15 are illustrated in fig1 a , 1 b , 2 a , and 2 b . these conventional outlet units 10 , 15 can have outlets 20 closely spaced , as they need not accommodate a locking feature on a power cord . these conventional outlet units 10 , 15 may include electrical conductors 30 to deliver power to the individual outlets 20 and / or to provide a connection to ground . many rack mountable pdus 110 are designed to fit within industry standard enclosures , such as a 42u enclosure , which limits the total length of vertical mount rack pdus 110 which may be used . due to the spacing gap required between outlets 20 to accommodate the volex locking feature , the total number of outlets 20 which can be placed on a standard electrical equipment rack pdu 110 is limited to a number smaller than consumers may desire . embodiments of the present disclosure facilitate the provision of an increased number of locking electrical outlets 20 that can fit in a limited amount of space . embodiments of the present disclosure are applicable to , for example , electrical equipment rack power distribution units 110 and uninterruptible power source ( ups ) devices as well as other power distribution devices . at least some embodiments of pdus 110 described in this disclosure include novel electrical outlet orientations and layouts which allow a greater number of locking electrical outlets 20 to be provided within a given space . illustrated in fig4 - 8 is an example of an electrical outlet configuration that may be utilized in some embodiments of ganged outlet units 80 in accordance with the present disclosure . the outlet configuration illustrated in fig4 - 8 includes two adjacent columns of electrical outlets 20 facing opposite of one another . in one column of electrical outlets 20 , the electrical outlets 20 are rotated 180 degrees from the electrical outlets 20 in the other column . the outlets 20 illustrated in fig4 - 8 are arranged in a 2 × 3 grid arrangement . in alternate embodiments , greater or fewer than six outlets 20 may be present . for example , a ganged outlet unit 80 could include four outlets , such as the four outlets in the top two rows illustrated in fig4 , which are arranged in a 2 × 2 grid arrangement . each outlet 20 includes two power terminals and one ground terminal . the present disclosure is not limited to the type of outlets illustrated . different outlets , such as those configured for use with , for example , european or chinese style plugs may also be utilized in different embodiments of the present disclosure . fig4 - 8 illustrate a ganged outlet unit 80 with six outlets , however , different embodiments may have different numbers of outlets 20 ( e . g . 2 columns of 3 outlets as shown or 2 columns of x outlets , with x being equal to 1 , 2 , 3 , 4 , etc .). further , different embodiments of ganged outlet units 80 may have outlets 20 configured differently than illustrated . for example , in some embodiments of a ganged outlet unit 80 , one or more outlets 20 may be rotated 180 degrees from what is illustrated in fig4 - 8 . in some embodiments of a ganged outlet unit 80 , one or more additional locking outlets 20 may be included with a space between the outlets 20 arranged in the adjacent columns and the additional outlets 20 , such as the space 40 illustrated in fig3 . in some embodiments of a ganged outlet unit 80 , one or more additional locking outlets 20 may be included rotated 90 degrees from the other outlets 20 and located adjacent to the other locking outlets 20 , but with an open space on the side of the additional outlets not adjacent the other outlets 20 . in other embodiments of a ganged outlet unit 80 , non - locking outlets may be included along with locking outlets 20 . in some embodiments , the columns of outlets 20 may be offset from one another such that outlets 20 in one column are not aligned with outlets 20 in another column some embodiments of a ganged outlet unit 80 may include more than two columns of outlets . in the example ganged outlet unit 80 of fig4 - 8 , the outlets 20 are in dual column arrangement with the ground terminals facing each other . in other embodiments , the outlets 20 could be arranged such that the ground terminals face away from each other . in at least one embodiment , all the line , neutral and ground terminals are connected by three separate metal conductors 90 . these connectors may be seen in the rear views of the ganged outlet unit 80 illustrated in fig5 , 7 , and 8 . in some embodiments , there are only three quick connect terminals 100 for the entire ganged outlet unit 80 , that is , one line , one neutral , and one ground . other embodiments may have a greater number of terminals 100 . optionally , the unit 80 could also be configured by using quick connect or solder terminals connected to a secondary pcb board for ganging ( bussing ) the line , neutral , or ground features . also optionally , line and / or neutral terminals on different outlets 20 can remain unganged to allow connection to individual or different power sources . the configuration of outlets 20 illustrated in fig4 - 8 provides advantages over electrical outlet configurations such as those illustrated in fig1 a - 3 . this is because ganged outlets 20 in a single column or row arrangement , such as those illustrated in fig1 a - 3 cannot accommodate the self - locking feature of self - locking power cords 50 , such as those provided by volex group plc . single column or row gang outlets require more chassis length for the same number of outlets 20 as ganged outlet units 80 according to the present disclosure . as such , at least some embodiments of the present disclosure facilitate fitting more locking outlets 20 in a small compact space than was previously achievable . in the configuration of outlets 20 illustrated in fig4 - 8 , adjacent outlets may be abutted against each other so that there is little or no spacing between outlets . in one embodiment , a spacing between adjacent outlets , e . g . a spacing between outlets in a vertical direction in fig4 , may be about 2 . 2 mm , and a spacing between opposite outlets , e . g . a spacing between outlets in a horizontal direction in fig4 , may be about 1 . 1 mm . this spacing may facilitate easier insertion or removal of power cords from the ganged outlet than would be possible if the outlets were more closely spaced . in at least one embodiment , the spacing and arrangement of outlets may result in a ganged outlet configuration with six outlets included in an outlet unit with a length of about 10 . 1 cm , a width of about 5 . 5 cm , and a surface area of about 55 . 5 square centimeters . greater spacing between outlets may be provided in some embodiments , which would result in a lower density of power outlets in the ganged outlet unit . in some embodiments , a ganged outlet unit 80 in accordance with the present disclosure may include one or more features that permit installation of the gang outlet 80 in a single direction only . to this end , the ganged outlet unit 80 may include an asymmetric electrical connector configuration , as is illustrated in fig7 and 8 . alternatively or additionally , opposite ends of the ganged outlet unit 80 may have different features which allow for the ganged outlet unit 80 to be installed in an outlet mount and / or pdu 110 in only a single direction . features according to the present disclosure which permit installation of gang outlets 80 in a single direction only may facilitate maintaining line and neutral terminals being in the same position in corresponding electrical outlets in each gang outlet 80 installed in a pdu . the self - locking feature of the ganged outlet unit 80 is illustrated in fig9 and 10 . there is a cutout 70 , or in some embodiments , a slot , recess , or depression formed in the side wall of the housing of the ganged outlet unit 80 corresponding to each locking outlet 20 . the mating power cord 50 has a self - locking tab 60 . a protrusion on the tab 60 engages the cutout , slot , recess , or depression 70 in the housing corresponding to an outlet 20 when the power cord 50 is plugged into the outlet 20 . the engagement of the protrusion on the tab 60 with the cutout , slot , recess , or depression 70 locks the power cord 50 in place in the outlet 20 . the self - locking tab 60 can be manually depressed to disengage the protrusion from the cutout , slot , recess , or depression 70 and allow the power cord 50 to be removed from the outlet 20 , as illustrated in fig1 . the ganged outlet unit 80 according to embodiments of the present disclosure may be used on a pdu 110 configured for mounting on an electronics equipment rack . one example of such a pdu 110 is illustrated in fig1 and 12 . the pdu of fig1 and 12 includes six ganged outlet units 80 having six electrical outlets 20 each . in alternate embodiments , pdus may include more or fewer ganged outlet units 80 and the ganged outlet units may include more or fewer than six electrical outlets 20 each . not all ganged outlet units 80 mounted to a pdu 110 need be configured in the same manner or with the same number of electrical outlets 20 . the pdu 110 of fig1 and 12 includes electrical bus lines ( not shown ) for delivering electrical power and providing ground to the electrical connections of the ganged outlet units 80 installed thereon . ganged outlet units 80 according to embodiments of the present invention can also be used more broadly in other applications including ups devices and other power distribution devices . having thus described several aspects of at least one embodiment of this invention , it is to be appreciated various alterations , modifications , and improvements will readily occur to those skilled in the art . such alterations , modifications , and improvements are intended to be part of this disclosure , and are intended to be within the spirit and scope of the invention . accordingly , the foregoing description and drawings are by way of example only .