Electric power system with maintenance bypass for uninterruptible power supply using closed transition operation
First Claim
1. A system for supplying electric power from a primary power source to a load, said system comprising:
- an uninterruptible power supply connected to said primary power source and including an alternate power source and a transfer switch selectively connecting the primary power source and said alternate power source to said load; and
maintenance bypass switch means comprising a first switch connected in series between said uninterruptible power supply and said load, a second switch bypassing said uninterruptible power supply and said first switch and connecting said primary power source directly to said load, and operating means operating said first and second switches simultaneously in opposition to selectively open one of said switches and close the other with both of said switches closed momentarily to provide closed transition operation in which at least one of said first and second switches is always closed.
1 Assignment
0 Petitions
Accused Products
Abstract
An uninterruptible power source having a static transfer switch which switches rapidly between a commercial power source and an alternate power source is removed from service by a maintenance bypass switch having a first switch in series with the uninterruptible power source and a second switch which shunts the uninterruptible power source and the first switch. The first and second switches are circuit breakers having handles which toggle between open and closed positions. The maintenance bypass switch includes an operator which operates the two circuit breakers in opposition with a closed transition so that one switch is always closed. An interlock prevents operation of the maintenance bypass switch when the alternate power source of the uninterruptible power supply is selected by the static transfer switch. An isolation switch between the uninterruptible power source and the commercial power source and also shunted by the second switch of the maintenance bypass switch is open together with the first switch of the maintenance bypass switch when the uninterruptible power source is to be isolated for maintenance.
123 Citations
5 Claims
-
1. A system for supplying electric power from a primary power source to a load, said system comprising:
-
an uninterruptible power supply connected to said primary power source and including an alternate power source and a transfer switch selectively connecting the primary power source and said alternate power source to said load; and maintenance bypass switch means comprising a first switch connected in series between said uninterruptible power supply and said load, a second switch bypassing said uninterruptible power supply and said first switch and connecting said primary power source directly to said load, and operating means operating said first and second switches simultaneously in opposition to selectively open one of said switches and close the other with both of said switches closed momentarily to provide closed transition operation in which at least one of said first and second switches is always closed. - View Dependent Claims (2, 3, 4, 5)
-
Specification