Electrical unit for a motor control center with ingress protection

Patent metadata

Field	Value
Publication number	US-10601204-B2
Application number	US-201815892579-A
Country	US
Kind code	B2
Filing date	Feb 9, 2018
Priority date	Feb 9, 2018
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

The present inventors have recognized that electrical units for Motor Control Centers (MCC's) can be improved to allow testing in a partially disconnected state while providing ingress protection through the use of sealing members without decreasing the size of the electrical unit. In particular, a full size electrical unit, able to advantageously accommodate a full array of electrical components like most other electrical units, can be partially withdrawn from an MCC for testing while still providing protection from the possibility of shock, gases and/or other hazards by way of sealing members such as gaskets and/or plates. Such sealing members can be mounted to the electrical unit to effectively seal the electrical unit with respect to the MCC when partially withdrawn.

First claim

What is claimed is:

1. An electrical unit for a Motor Control Center (MCC), comprising:
a support structure for supporting an electrical component configured to receive first and second pluralities of signals from an MCC;
a front wall and opposing sidewalls attached to the support structure, the front wall, the opposing sidewalls and the support structure forming an interior volume of the electrical unit containing the electrical component with the front wall providing a door;
an actuating mechanism for selectively moving the electrical unit with respect to the MCC, the actuating mechanism having a handle protruding through the front wall, the handle being moveable between a plurality of positions including: a first position corresponding to a connected position in which the electrical unit is fully inserted in the MCC with the first and second pluralities of signals being connected; a second position corresponding to a test position in which the electrical unit is partially withdrawn from the MCC with the first plurality of signals being disconnected and the second plurality of signals being connected; and a third position corresponding to a disconnected position in which the electrical unit is partially withdrawn from the MCC with the first and second pluralities of signals being disconnected; and
sealing members attached to the opposing, sidewalls in areas external to the interior volume of the electrical unit, wherein the sealing members form barriers in gaps leading to an interior volume of the MCC between the opposing sidewalls and the MCC to provide arc fault protection when the electrical unit is partially withdrawn from the MCC in the second and third position.

2. The electrical unit of claim 1 , wherein the first plurality of signals comprises multi-phase electrical power signals.

3. The electrical unit of claim 2 , further comprising a plurality of load stabs for connecting or disconnecting the multi-phase electrical power signals, wherein the load stabs snap-in to bus bars of the MCC to connect the multi-phase electrical power signals in the first position, and wherein the load stabs snap-out of bus bars of the MCC to disconnect the multi-phase electrical power signals in the second and third positions.

4. The electrical unit of claim 2 , wherein the second plurality of signals comprises communications and control signals.

5. The electrical unit of claim 4 , wherein the second plurality of signals further comprises electrical power signals providing lower power than the multi-phase electrical power signals.

6. The electrical unit of claim 1 , further comprising a push button protruding through the front wall, wherein movement of the handle requires actuation of the push button.

7. The electrical unit of claim 1 , wherein the electrical unit is locked in the MCC in the first, second and third position, and wherein the plurality of positions further includes a fourth position corresponding to a withdrawal position in which the electrical unit can be fully removed from the MCC.

8. The electrical unit of claim 1 , wherein the sealing members are gaskets, and further comprising a sealing member that is a plate, the plate being attached to the front wall and the opposing sidewalls, wherein the plate opposes the support structure, and wherein the plate prevents access to the interior volume when the electrical unit is partially withdrawn from the MCC in the second and third positions.

9. The electrical unit of claim 1 , wherein the actuating mechanism comprises a cam pivotally mounted to the support structure and a linkage connecting the cam to the handle.

10. The electrical unit of claim 1 , further comprising a rotary circuit breaker protruding through the front wall, the rotary circuit breaker being configured to disconnect the first plurality of signals when in the first position.

11. The electrical unit of claim 1 , wherein the sealing members form barriers in the gaps when the electrical unit is in between the second and third positions.

12. A Motor Control Center (MCC),
a section forming a shell around a device mounting volume for supporting an electrical unit, the electrical unit comprising:
a support structure for supporting an electrical component configured to receive first and second pluralities of signals from the MCC;
a front wall and opposing sidewalls attached to the support structure, the front wall, the opposing sidewalls and the support structure forming an interior volume of the electrical unit containing the electrical component with the front wall providing a door;
an actuating mechanism for selectively moving the electrical unit with respect to the MCC, the actuating mechanism having a handle protruding through the front wall, the handle being moveable between a plurality of positions including: a first position corresponding to a connected position in which the electrical unit is fully inserted in the MCC with the first and second pluralities of signals being connected to the MCC; a second position corresponding to a test position in which the electrical unit is partially withdrawn from the MCC with the first plurality of signals being disconnected from the MCC and the second plurality of signals being connected to the MCC; and a third position corresponding to a disconnected position in which the electrical unit is partially withdrawn from the MCC with the first and second pluralities of signals being disconnected from the MCC; and
sealing members attached to the opposing sidewalls in areas external to the interior volume of the electrical unit, wherein the sealing members form barriers in gaps leading to an interior volume of the MCC between the opposing sidewalls and the MCC to provide arc fault protection when the electrical unit is partially withdrawn from the MCC in the second and third positions.

13. The MCC of claim 12 , wherein the first plurality of signals comprises multi-phase electrical power signals.

14. The MCC of claim 13 , further comprising a plurality of load stabs for connecting or disconnecting the multi-phase electrical power signals, wherein the load stabs snap-in to bus bars of the MCC to connect the multi-phase electrical power signals in the first position, and wherein the load stabs snap-out of bus bars of the MCC to disconnect the multi-phase electrical power signals in the second and third positions.

15. The MCC of claim 13 , wherein the second plurality of signals comprises communications and control signals.

16. The MCC of claim 12 , further comprising a push button protruding through the front wall, wherein movement of the handle requires actuation of the push button.

17. The MCC of claim 12 , wherein the electrical unit is locked in the MCC in the first, second and third position, and wherein the plurality of positions further includes a fourth position corresponding to a withdrawal position in which the electrical unit can be fully removed from the MCC.

18. The MCC of claim 12 , wherein the sealing members are gaskets, and further comprising a sealing member that is a plate, the plate being attached to the front wall and the opposing sidewalls, wherein the plate opposes the support structure, and wherein the plate prevents access to the interior volume when the electrical unit is partially withdrawn from the MCC in the second and third positions.

19. The MCC of claim 12 , wherein the actuating mechanism comprises a cam pivotally mounted to the support structure and a linkage connecting the cam to the handle.

20. The MCC of claim 12 , further comprising a rotary c

Assignees

• Rockwell Automation Tech Inc

Inventors

• Bellows Troy M
• Schimek Emily M
• Lorek Tomasz

Classifications

• H05K5/023

  Handles; Grips · CPC title

• H02B1/28 Primary

  dustproof, splashproof, drip-proof, waterproof or flameproof · CPC title

• H02B1/21

  Bus-bar arrangements for rack-mounted devices with withdrawable units · CPC title

• H02B1/36

  with withdrawable units · CPC title

• H02B1/306

  Accessories, e.g. windows · CPC title