POWER SUPPLY APPARATUS FOR FIELD DEVICES

• US 20080143190A1
• Filed: 12/14/2006
• Published: 06/19/2008
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Rebbereh, Carsten
• Granted Patent: US 7,573,153 B2
• Time in Patent Office: Days
• US Class Current: 307/113
• CPC Class Codes: H02J 11/00 Circuit arrangements for providing service supply to auxiliaries of stations in which electric power is generated, distributed or converted
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence

Abstract

An apparatus for supplying DC power to a field device, such as a motor, starter or actuator, includes a multi-pole main switch and a DC voltage supply device, both of which are connected at their respective AC-voltage input sides to a line voltage via a line protection. The DC-voltage side of the DC voltage supply device is connected via a two-pole switch to respective lines of the same power cable that connects output terminals of the apparatus to the field device. The multi-pole main switch and the two-pole switch are ganged. This approach eliminates a separate DC power cable between the apparatus and the field device.

Claims

1. An apparatus for supplying DC power to at least one field device, comprising:

a multi-pole main switch having an input side receiving an AC voltage from a power mains and an output side supplying a switched AC voltage to output terminals of the apparatus;

a power cable connecting the output terminals to the at least one field device; and

a DC voltage supply device having an input side receiving the AC voltage from the power mains and a DC voltage output side connected via a two-pole switch to two of the output terminals of the apparatus, wherein the multi-pole main switch and the two-pole switch are ganged.

2. The apparatus of claim 1, wherein each field device comprises a switched mode power supply which is buffered so as to bridge brief interruptions of AC power from the power mains.

3. The apparatus of claim 1, wherein the multi-pole main switch and the two-pole switch are ganged so as to provide break-before-make operation.

4. The apparatus of claim 1, wherein the multi-pole main switch and the two-pole switch form a single unit.

5. The apparatus of claim 1, wherein the multi-pole main switch is a load-break switch.

6. The apparatus of claim 1, wherein the field device is a converter.

7. The apparatus of claim 1, wherein the field device is a motor starter.

8. The apparatus of claim 1, wherein the field device is an input/output module.

9. The apparatus of claim 1, further comprising a fuse disposed on the input side of the multi-pole switch or on the input side of the DC voltage supply device, or both, as line protection.