Adaptive Power Strip

• US 20090236909A1
• Filed: 03/18/2009
• Published: 09/24/2009
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: Vertiv Corporation (Vertiv Holdings Co.)
• Original Assignee: Liebert Corporation (Vertiv Holdings Co.)
• Inventors: Ferguson, Kevin R., Wassermann, Michael, Aldag, Philip R.
• Granted Patent: US 7,982,335 B2
• Time in Patent Office: Days
• US Class Current: 307/39
• CPC Class Codes: H01R 25/006 the coupling part being secured to apparatus or structure, e.g. duplex wall receptacle
• CPC Class Codes: H01R 25/142 Their counterparts
• CPC Class Codes: H01R 25/145 Details, e.g. end pieces or joints H01R25/147 takes precedence

Abstract

An adaptive power strip has a power rail. A power entry module and one or more receptacle modules having plug receptacles are mounted on the power rail. The power entry module has a power inlet to which a source of power can be coupled. The power entry module distribute power from the power source to the power rail. The receptacle modules distribute power from the power rail tot the respective plug receptacles. In an aspect, the power entry module has a communications module that discovers receptacle modules on the power rail having data communications capability and if a receptacle module does not have a unique identifier assigned to it, assigns a unique identifier to the receptacle module that the receptacle module stores in a memory. The communications modules also retrieves from each receptacle module having data communications capability, information about the characteristics of the receptacle module that the communications module stores in a memory. The communications module maintains an inventory in memory of the receptacle modules on the power rail that includes information about the characteristics of the receptacle modules. In an aspect, receptacle modules determine their locations on the power rail and send information to the communications module that the communications module uses to determine the location of the receptacle modules on the power rail. In an aspect, the power entry module determines the type of power service provided to it at its power inlet.

Claims

1. A power strip, comprising:

a power rail having a power bus capable of distributing up to three phase AC power and a communications bus including a plurality of power bus conductors and a plurality of communications bus conductors recessed in an longitudinally extending chassis that run through the chassis along the length of the chassis, the power bus including a hot conductor for each of the three phases (L1, L2, L3), a neutral conductor and a ground conductor;

a power entry module received on the power rail, the power entry module having a power inlet to which a source of power can be coupled, a plurality of power entry module power bus terminals that mate with the power bus conductors of the power rail and a plurality of power entry module communications bus terminals that mate with the communications bus conductors of the power rail;

a plurality of receptacle modules receivable on the power rail, each receptacle module including a plurality of receptacle module power terminals that mate with the power bus conductors of the power rail, each receptacle module having data communications capability having a plurality of receptacle module communications bus terminals that mate with the communications bus conductors of the power rail, each receptacle module having a plurality of plug receptacles, each receptacle module mounted on the power rail distributing AC power from the power rail to its plug receptacles;

the receptacle modules selectable from receptacle modules having a plurality of different characteristics;

the power entry module including a communications module that conducts a discovery process when a receptacle module having data communication capability is mounted on the power rail, the communication module querying that receptacle module via the communications bus to determine whether that receptacle module had a unique identifier assigned to it and if not, assigns a unique identifier to that receptacle module that the communications module sends to the receptacle module via the communications bus and that the receptacle module stores in a memory of the receptacle module, the communications module via the communications bus retrieving from that receptacle module information indicative of the characteristics of that receptacle module and a location of that receptacle module on the power rail that the communications module stores in a memory of the communications module, the communications module maintaining in memory of the communications module an inventory of each receptacle module mounted on the power rail to which the communication module assigned a unique identifier that includes the information indicative of the characteristics of each such receptacle module and its location on the power rail.

2. The apparatus of claim 1 wherein the communication module makes the information in its inventory of receptacle modules accessible to a display module coupled to the communications module.

3. The apparatus of claim 2 wherein the display module has selectable views for displaying information about power utilization of the power strip, about each receptacle module having monitoring capability that is mounted on the power rail of the power strip and about each plug receptacle of each such receptacle module that also has plug receptacle monitoring capability.

4. The apparatus of claim 1 wherein the communications module makes the information in its inventory of receptacle modules accessible to a remote system to which the communications module is coupled via a network.

5. The apparatus of claim 4 wherein the network is the Internet.

6. The apparatus of claim 1 wherein each receptacle module having data communications capability has a display that displays numeric information, each receptacle module assigned a unique identifier displaying on its display its assigned unique identifier.

7. The apparatus of claim 6 wherein the display includes a portion that indicates whether a receptacle module having been assigned a unique identifier has been discovered by the communications module.

8. The apparatus of claim 7 wherein the display is a seven segment LED display having a decimal point, the decimal point comprising the portion that indicates whether the receptacle module has been discovered by the communications module, the receptacle module illuminating the decimal point of the display to indicate that the receptacle module has not been discovered by the communications module.

9. The apparatus of claim 8 wherein a receptacle module mounted on the power rail that has not been assigned a unique identifier flashes the segments of its display in a sequence.

10. The apparatus of claim 1 wherein the power rail includes a resistive element that runs through the chassis along the length of the chassis, a DC power supply of the power entry module providing DC power to the resistive element through a terminal that mates with the resistive element;

the receptacle module including a voltage sensing circuit coupled through a terminal that mates to the resistive element at a point spaced from a point where the power entry module provides the DC voltage to the resistive element, the receptacle module including a monitor/control circuit that generates information indicative of a position of the receptacle module on the power rail based on a DC voltage of the resistive element sensed by the voltage sensing circuit.

11. The apparatus of claim 10 wherein the monitor/control circuit of the receptacle module sends the information indicative of the location of the receptacle module on the power rail to the power entry module via the communications bus.

12. The apparatus of claim 11 wherein the communications module of the power entry module receives the information indicative of the location of the receptacle module on the power rail and determines the location of the receptacle module on the power rail based on this information.

13. The apparatus of claim 12 wherein the information indicative of the location of the receptacle module on the power rail is a digitized voltage generated by the monitor/control circuit by digitizing the voltage sensed by the voltage sensing circuit wherein the digitized voltage is proportional to the location of the receptacle module on the power rail.

14. The apparatus of claim 10 wherein the resistance of the resistive element continuously increases along the length of the resistive element starting from an end of the resistive element closest to the power entry module.

15. The apparatus of claim 14 wherein the resistive element is a carbon plated conductor.

16. The apparatus of claim 10 wherein the resistive element includes a segmented conductor having a plurality of conductors with ends of adjacent conductors bridged by a resistor.

17. The apparatus of claim 1 wherein the power entry module communications bus terminals include a communications bus power terminal, the communications bus terminals of each of the receptacle modules having data communications capability including data and power terminals, each receptacle module having data communications capability including a receptacle module DC power supply having an output coupled to that receptacle, module communications bus power terminal to provide DC power to the communications bus of the power rail that is provided to the communications module of the power entry module to provide a source of secondary DC power to the communications module.

18. The apparatus of claim 1 wherein the power inlet has a hot terminal for each of the three phases (L1, L2, L3), a neutral terminal and a ground terminal, the power entry module including a monitor/control circuit that based on the presence or absence of a voltage on the neutral terminal of the power inlet and based on voltage differences between at least two of the phases at the hot terminals of the power inlet, determines a type of power service provided to the power inlet and based thereon sets the type of power service that the power entry module is distributing to the power bus of the power rail.

19. The apparatus of claim 18 wherein:

if a difference between an L1 voltage and an L2 voltage is not greater than 120 volts, the monitor/control circuit of the power entry module determines the power service is 1-pole, 3-wire;

if the difference between the L1 voltage and L2 voltage is greater than 120 volts and a difference between an L3 voltage and the L1 voltage is not greater than 120 volts, the monitor/control circuit of the power entry module determines the power service is 2-pole, 3-wire;

if the differences between the L1 and L2 voltages and the L3 and L1 voltages are both greater than 120 volts and a neutral voltage is not present, the monitor/control circuit of the power entry module determines the power service is 3-pole, 4-wire; and

if the differences between the L1 and L2 voltages and the L3 and L1 voltages are both greater than 120 volts and a neutral voltage is present, the monitor/control circuit of the power entry module determines the power service is 3-pole, 5-wire.

20. The apparatus of claim 1 including a plurality of receptacle modules mounted on the power rail that distribute AC power to their plug receptacles through relays, each receptacle module including a monitor/control circuit that is remotely programmable via commands sent over the communications bus to the receptacle module to set a power-up delay for each of the plug receptacles wherein a power-up sequence of the plug receptacles of the plurality of receptacle modules is established by programming power-up delays for each of the plug receptacles of each of the plurality of receptacle modules.

21. The apparatus of claim 1 wherein the receptacle module distributes AC power to its plug receptacles through relays.

22. The apparatus of claim 21 including a plurality of the receptacle modules mounted on the power rail.

23. The apparatus of claim 1 including a plurality of the receptacle modules mounted on the power rail.

24. The apparatus of claim 23 wherein each receptacle module distributes one of single phase AC power or polyphase AC power to its plug receptacles.

25. The apparatus of claim 1 wherein the receptacle modules are selectable from receptacle modules having a plurality of different power configurations, each receptacle module having a color code that indicates its power configuration, each of the plurality of different power configurations having a unique color code.

26. The apparatus of claim 25 wherein each receptacle module includes a second color code that indicates a region for which the receptacle module is configured, each region having a unique color code.

27. The apparatus of claim 26 wherein each receptacle module includes a label having the first and second color codes, wherein a background color of the label has the color of the second color code and a section of the label includes the first color code.

28. The apparatus of claim 27 wherein the section of the label having the first color code includes text identifying the power configuration and background having the color of the first color code.

29. The apparatus of claim 1 wherein the receptacle modules include a receptacle module having a circuit breaker, that receptacle module distributing AC power from the power rail through the circuit breaker to that receptacle module'"'"'s plug receptacles, that receptacle module having a monitor/control circuit and a voltage sensing circuit coupled thereto that senses voltage on a hot output terminal of the circuit breaker, the monitor/control circuit determining that the circuit breaker is open when the voltage on that hot output terminal of the circuit breaker is less than a reference voltage and energizes a display to indicate that the circuit breaker is open.

30. The apparatus of claim 29 wherein the monitor/control circuit of the receptacle module having the display flashes the display when it energizes the display.

31. The apparatus of claim 30 wherein the display is a seven segment LED display.

32. A power strip, comprising:

a power rail having a power bus capable of distributing up to three phase AC power and a communications bus, the power bus including a plurality of power bus conductors and a plurality of communications bus conductors recessed in longitudinally extending chassis that run through the chassis along the length of the chassis, the communications bus conductors including data and power lines, the power rail including a resistive element that runs through the chassis along the length of the chassis;

a power entry module received on the power rail, the power entry module having a power inlet to which a source of power can be coupled, a plurality power entry module power bus terminals that mate with the power bus conductors of the power rail and a plurality of power entry module communications bus terminals that mate with the communications bus conductors of the power rail, the power entry module having a power entry module DC power supply and provides a DC voltage to the resistive element through a terminal that mates with the resistive element;

at least one receptacle module received on the power rail, the receptacle module including a plurality of receptacle module power terminals that mate with the power bus conductors of the power rail, a plurality of receptacle module communications bus terminals that mate with the communications bus conductors of the power rail, the receptacle module having a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the receptacle modules plug receptacles, the receptacle module including a voltage sensing circuit coupled through a terminal that mates to the resistive element at a point spaced from a point where the power entry module provides the DC voltage to the resistive element, the receptacle module including a monitor/control circuit that generates information indicative of a position of the receptacle module on the power rail based on a DC voltage of the resistive element sensed by the voltage sensing circuit.

33. The apparatus of claim 32 wherein the resistance of the resistive element continuously increases along the length of the resistive element starting from an end of the resistive element closest to the power entry module.

34. The apparatus of claim 33 wherein the resistive element is a carbon plated conductor.

35. The apparatus of claim 32 wherein the resistive element includes a segmented conductor having a plurality of conductors with ends of adjacent conductors bridged by a resistor.

36. The apparatus of claim 32 wherein the monitor/control circuit of the receptacle module sends the information indicative of the location of the receptacle module on the power rail to the power entry module via the communications bus.

37. The apparatus of claim 36 wherein the power entry module includes a communications module that receives the information indicative of the location of the receptacle module on the power rail and determines the location of the receptacle module on the power rail based on this information.

38. The apparatus of claim 36 wherein the information indicative of the location of the receptacle module on the power rail is a digitized voltage generated by the monitor/control circuit by digitizing the voltage sensed by the voltage sensing circuit wherein the digitized voltage is proportional to the location of the receptacle module on the power rail.

39. The apparatus of claim 32 wherein the receptacle module distributes AC power to its plug receptacles through relays.

40. The apparatus of claim 32 including a plurality of the receptacle modules mounted on the power rail.

41. The apparatus of claim 39 wherein each receptacle module distributes one of single phase AC power or polyphase power to its plug receptacles.

42. A receptacle module for mounting on a power strip, comprising:

a plurality of receptacle module power terminals that mate with power bus conductors of the power rail;

a plurality of receptacle module communications bus terminals that mate with communications bus conductors of the power rail;

a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the receptacle modules plug receptacles;

a voltage sensing circuit coupled through a terminal that mates to a resistive element that extends along a chassis of the power rail;

a monitor/control circuit that generates information indicative of a position of the receptacle module on the power rail based on a DC voltage of the resistive element sensed by the voltage sensing circuit.

43. The apparatus of claim 42 wherein the monitor/control circuit of the receptacle module sends the information indicative of the location of the receptacle module on the power rail over the communications bus.

44. The apparatus of claim 43 wherein the information indicative of the location of the receptacle module on the power rail is a digitized voltage generated by the monitor/control circuit by digitizing the voltage sensed by the voltage sensing circuit wherein the digitized voltage is proportional to the location of the receptacle module on the power rail.

45. The apparatus of claim 42 wherein each receptacle module distributes one of single phase AC power or polyphase power.

46. A power strip, comprising:

a power rail having a power bus capable of distributing up to three phase AC power and a communications bus including a plurality of power bus conductors and a plurality of communications bus conductors recessed in an longitudinally extending chassis that run through the chassis along the length of the chassis, the power bus including a hot conductor for each of the three phases (L1, L2, L3), a neutral conductor and a ground conductor;

a power entry module received on a module mounting side of the power rail, the power entry module having a power inlet to which a source of power can be coupled, the power inlet having a hot terminal for each of the three phases (L1, L2, L3), a neutral terminal and a ground terminal, a plurality power entry module power bus terminals that mate with the power bus conductors of the power rail and a plurality of power entry module communications bus terminals that mate with the communications bus conductors of the power rail, the power entry module including a monitor/control circuit that based on the presence or absence of a voltage on the neutral terminal of the power inlet and based on voltage differences between at least two of the phases at the hot terminals of the power inlet, determines a type of power service provided to the power inlet and based thereon sets the power service that the power entry module is distributing to the power bus of the power rail;

at least one receptacle module received on the power rail, the receptacle module including a plurality of receptacle module power terminals that mate with the power bus conductors of the power rail, the receptacle module having a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the receptacle modules plug receptacles.

47. The apparatus of claim 46 wherein:

if a difference between an L1 voltage and an L2 voltage is not greater than 120 volts, the monitor/control circuit determines the power service is 1-pole, 3-wire;

if the difference between the L1 voltage and L2 voltage is greater than 120 volts and a difference between an L3 voltage and the L1 voltage is not greater than 120 volts, the monitor/control circuit determines the power service is 2-pole, 3-wire;

if the differences between the L1 and L2 voltages and the L3 and L1 voltages are both greater than 120 volts and a neutral voltage is not present, the monitor/control circuit determines the power service is 3-pole, 4-wire; and

if the differences between the L1 and L2 voltages and the L3 and L1 voltages are both greater than 120 volts and a neutral voltage is present, the monitor/control circuit determines the power service is 3-pole, 5-wire.

48. The apparatus of claim 46 wherein the receptacle module distributes AC power to its plug receptacles through relays.

49. The apparatus of claim 46 including a plurality of the receptacle modules mounted on the power rail.

50. The apparatus of claim 49 wherein each receptacle module distributes one of single phase AC power or polyphase AC power.

51. A power strip, comprising:

a power rail having a power bus capable of distributing up to three phase AC power and a communications bus, the power rail including a plurality of power bus conductors and a plurality of communications bus conductors recessed in an longitudinally extending chassis that run through the chassis along the length of the chassis, the communications bus conductors including data and power lines;

a power entry module received on the power rail, the power entry module having a power inlet to which a source of power can be coupled, a plurality power entry module power bus terminals that mate with the power bus conductors of the power rail and a plurality of power entry module communications bus terminals that mate with the communications bus conductors of the power rail, the power entry module communications bus terminals including a communications bus power terminal, the power entry module having a power entry module DC power supply that provides DC power to a communications module of the power entry module; and

at least one receptacle module received on the power rail, the receptacle module including a plurality of receptacle module power terminals that mate with the power bus conductors of the power rail, a plurality of receptacle module communications bus terminals that mate with the communications bus conductors of the power rail, the receptacle module communications bus terminals having data and power terminals, the receptacle module having a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the receptacle modules plug receptacles, a receptacle module DC power supply having an output coupled to the receptacle module communications bus power terminal to provide a source of secondary DC power for the communications module that is provided to the communications module through the power entry module.

52. The apparatus of claim 51 wherein the receptacle module distributes AC power to its plug receptacles through relays.

53. The apparatus of claim 51 including a plurality of the receptacle modules mounted on the power rail.

54. The apparatus of claim 53 wherein each receptacle module distributes one of single phase AC power or polyphase AC power to its plug receptacles.

55. A receptacle module for mounting on a power strip having a power rail, comprising:

a plurality of receptacle module power terminals that mate with power bus conductors of the power rail and a plurality of receptacle module communications bus terminals that mate with communications bus conductors of the power rail, the receptacle module communications bus terminals having data and power terminals;

a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the receptacle modules plug receptacles;

a receptacle module DC power supply having an output coupled to the receptacle module communications bus power terminal to provide DC power to the communications bus of the power rail.

56. The apparatus of claim 55 wherein the receptacle module distributes AC power to its plug receptacles through relays.

57. The apparatus of claim 55 wherein the receptacle module distributes one of single phase AC power or polyphase AC power to its plug receptacles.

58. A power strip, comprising:

a power rail having a power bus capable of distributing up to three phase AC power, the power bus including a plurality of power bus conductors recessed in an longitudinally extending chassis that ran through the chassis along the length of the chassis,

a power entry module received on the power rail, the power entry module having a power inlet to which a source of power can be coupled and a plurality power entry module power bus terminals that mate with the power bus conductors of the power rail; and

at least one receptacle module received on the power rail, the receptacle module including a plurality of receptacle module power terminals that mate with power bus conductors of the power rail and that are coupled to a circuit breaker of the receptacle module, the receptacle module having a plurality of plug receptacles, the receptacle module distributing AC power from the power rail through the circuit breaker to the receptacle modules plug receptacles, the receptacle module including a monitor/control circuit and a voltage sensing circuit coupled thereto that senses voltage on a hot output terminal of the circuit breaker, the monitor/control circuit determining that the circuit breaker is open when the voltage on that hot output terminal of the circuit breaker is less than a reference voltage and energizes a display to indicate that the circuit breaker is open.

59. The apparatus of claim 58 wherein the monitor/control circuit flashes the display when it energizes the display.

60. The apparatus of claim 59 wherein the display is a seven segment LED display.

61. The apparatus of claim 58 wherein the receptacle module distributes AC power to its plug receptacles through relays.

62. The apparatus of claim 58 including a plurality of the receptacle modules mounted on the power rail.

63. The apparatus of claim 62 wherein each receptacle module distributes one of single phase AC power or polyphase AC power to its plug receptacles.

64. A receptacle module for mounting on a power strip having a power rail, comprising:

a plurality of receptacle module power terminals that mate with power bus conductors of the power rail and a plurality of receptacle module communications bus terminals that mate with communications bus conductors of the power rail, the receptacle module communications bus terminals having data and power terminals;

a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the receptacle module plug receptacles;

a monitor/control circuit and a voltage sensing circuit coupled thereto that senses voltage on a hot output terminal of the circuit breaker, the monitor/control circuit determining that the circuit breaker is open when the voltage on that hot output terminal of the circuit breaker is less than a reference voltage and energizes a display to indicate that the circuit breaker is open.

65. The apparatus of claim 64 wherein the monitor/control circuit flashes the display when it energizes the display.

66. The apparatus of claim 65 wherein the display is a seven segment LED display.

67. The apparatus of claim 64 wherein the receptacle module distributes AC power to its plug receptacles through relays.

68. The apparatus of claim 64 wherein the receptacle module distributes one of single phase AC power or polyphase AC power to its plug receptacles.

69. A power strip, comprising:

a power rail having a power bus capable of distributing up to three phase AC power and a communications bus including a plurality of power bus conductors and a plurality of communications bus conductors recessed in a longitudinally extending chassis that run through the chassis along the length of the chassis, the power bus including a hot conductor for each of the three phases (L1, L2, L3), a neutral conductor and a ground conductor;

a power entry module received on the power rail, the power entry module having a power inlet to which a source of power can be coupled, the power inlet having a hot terminal for each of the three phases (L1, L2, L3), a neutral terminal and a ground terminal, a plurality of power entry module power bus terminals that mate with the power bus conductors of the power rail and a plurality of power entry module communications bus terminals that mate with the communications bus conductors of the power rail;

at least one receptacle module received on the power rail, the receptacle module including a plurality of receptacle module power terminals that mate with the power bus conductors of the power rail, the receptacle module having a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the receptacle modules plug receptacles, the receptacle module having a color code that indicates a power configuration of the receptacle module.

70. The apparatus of claim 69 wherein the power rail can have a plurality of receptacle modules mounted thereon, the receptacle modules selectable from receptacle modules having a plurality of different power configurations, each receptacle module having the color code that indicates its power configuration, each of the plurality of different power configurations having a unique color code.

71. The apparatus of claim 70 wherein each receptacle module includes a second color code that indicates a region for which the receptacle module is configured, each region having a unique color code.

72. The apparatus of claim 71 wherein each receptacle module includes a label having the first and second color codes, wherein a background color of the label has the color of the second color code and a section of the label includes the first color code.

73. The apparatus of claim 72 wherein the section of the label having the first color code includes text identifying the power configuration and background having the color of the first color code.

74. The apparatus of claim 69 wherein the receptacle module distributes AC power to its plug receptacles through relays.

75. The apparatus of claim 69 wherein each receptacle module distributes one of single phase AC power or polyphase AC power to its plug receptacles.

76. A plurality of receptacle modules for mounting on a power strip, the power strip having a power rail having a power bus capable of distributing up to three phase AC power including a plurality of power bus conductors recessed in a longitudinally extending chassis that run through the chassis along the length of the chassis, the power bus including a hot conductor for each of the three phases (L1, L2, L3), a neutral conductor and a ground conductor, comprising:

the receptacle modules selectable from receptacle modules having different power configurations, each power configuration having a unique color code,

each receptacle module including a plurality of receptacle module power terminals that mate with the power bus conductors of the power rail, the receptacle module having a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the receptacle modules plug receptacles, the receptacle module having the unique color code that indicates the power configuration of the receptacle module.

77. The apparatus of claim 76 wherein each receptacle module includes a second color code that indicates a region for which the receptacle module is configured, each region having a unique color code.

78. The apparatus of claim 77 wherein each receptacle module includes a label having the first and second color codes, wherein a background color of the label has the color of the second color code and a section of the label includes the first color code.

79. The apparatus of claim 78 wherein the section of the label having the first color code includes text identifying the power configuration and background having the color of the first color code.

80. The apparatus of claim 76 wherein the receptacle modules include a receptacle module that distributes AC power to its plug receptacles through relays.

81. The apparatus of claim 76 wherein each receptacle module distributes one of single phase AC power or polyphase AC power to its plug receptacles.

82. A receptacle module for mounting on a power strip, the power strip having a power rail having a power bus capable of distributing up to three phase AC power including a plurality of power bus conductors recessed in a longitudinally extending chassis that run through the chassis along the length of the chassis, the power bus including a hot conductor for each of the three phases (L1, L2, L3), a neutral conductor and a ground conductor, the receptacle module comprising:

a housing having a contact block, the contact block having a plurality of blades that mate with respective slots in the power rail in which the power bus conductors of the power rail run, each blade including a shroud between which a contact that mates with one of the power conductors of the power rail is disposed, each contact having a lower portion having at least one pair of spring contacts and an upper portion having a terminal; and

a plurality of plug receptacles, the receptacle module distributing AC power from the power rail to the plug receptacles.

83. The apparatus of claim 82 wherein the lower portion of each contact includes a plurality of pairs of spring contacts.

84. The apparatus of claim 83 wherein the receptacle module has a power configuration and the contact block includes only blades for connecting to those of the power conductors of the power rails needed for the power configuration.

85. A portable display for a power strip, the power strip having a power rail having a power bus capable of distributing up to three phase AC power and a communications bus, a power entry module received on the power rail that distributes power from a source of AC power to a power bus of the power rail, a plurality of receptacle modules receivable on the power rail, each receptacle module including a plurality of receptacle module power terminals that mate with the power bus conductors of the power rail, each receptacle module having a plurality of plug receptacles, each receptacle module mounted on the power rail distributing AC power from the power rail to its plug receptacles, the receptacle modules selectable from receptacle modules having a plurality of different characteristics including receptacle modules having data communications capability having a plurality of receptacle module communications bus terminals that mate with the communications bus conductors of the power rail, the portable display module comprising:

a housing having a display screen;

a plurality of selectable views for displaying information about power utilization of the power strip, about each receptacle module having monitoring capability that is mounted on the power rail of the power strip and about each plug receptacle of each such receptacle module that also has plug receptacle monitoring capability.

86. The apparatus of claim 85 wherein the display module includes a scroll wheel that is rotatable to identify a desired view and depressable to select the identified view.

87. The apparatus of claim 86 wherein the scroll wheel is the only navigation device of the display module.

88. The apparatus of claim 85 wherein the display module has a data communications port that is couplable to at least one of the power rail, power entry module and receptacle modules.

89. The apparatus of claim 88 wherein the display module has a data communications port that is couplable to an Ethernet port of a communications module of the power entry module by an Ethernet cable.

90. The apparatus of claim 85 wherein the display module communicates wirelessly with at least one of the power entry module and receptacle modules.

91. The apparatus of claim 85 wherein the display module communicates wirelessly with a communications module of the power entry module.