GB252231A - Improvements in or relating to the control of apparatus at an electric power substation from a central control office - Google Patents

Abstract

252,231. Automatic Telephone Manufacturing Co., Ltd., and Remington, C. Feb. 13, 1925. Drawings to Specification. Selective distant control systems and apparatus; tell-tale apparatus.-Relates to a system for supervising and controlling from a remote point the operation and condition of a number of apparatus units at a substation. The selection of apparatus at the controlled station is visually by transmitting a signal from the controlled to the controlling station over the same lines as those over which the selecting signal is transmitted. Supervisory signals for indicating the position of apparatus, e.g. circuit breakers at the substations are also transmitted over the same lines. A further feature resides in the arrangement whereby the lines are automatically taken into use when the operator at the central station desired to control apparatus at the substation or when a supervisory signal is to be sent. Three line wires are used, two being employed for the transmission of selecting, checking and supervisory signals so as to establish a clean circuit including the third line whereby meter readings may be obtained at the control office or any desired operation, such as the control of a circuit breaker may be effected at the substation. Further feature reside in the provision of controlling arrangements for preventing the operation of the supervisory signalling apparatus when the selecting equipment is in operation and vice versa, and in the use of two switches at the substation which ensure that the operation of the selected apparatus can only be proceeded with when the switches occupy complementary positions. The Provisional Specification describes an arrangement wherein two rotary switches at each station are employed. The keys at the control station are associated with one switch which operates to send impulses over the line until the contact marked by the operated switch is reached. The impulses operate both switches at the substation through a corresponding number of steps after which one switch is cut out of circuit and remains on the selected contact, while the other switch continues to rotate to transmit impulses back to the control station. These impulses control the second switch at 'the control station and, by means of a lamp, provide a check on the selection. As soon as the correct selection is accomplished and the selected apparatus operated, impulses for operating supervisory signalling apparatus are transmitted back from the substation by the selecting switch and the first switch at the control office is restored to its normal position. This Specification also refers to an arrangement wherein each impulse transmitted from the control station is followed by an impulse transmitted from the substation. The system described is identical with that described in Specification 252,230. Specifications 258,012, 258,178, and 258,179 also are referred to.