GE L90 Instruction Manual

Also see for L90: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

Contents

4-8 L90 Line Differential Relay GE Multilin4.2 FACEPLATE INTERFACE 4 HUMAN INTERFACES44.2.3 DISPLAYAll messages are displayed on a 2 × 20 character vacuum fluorescent display to make them visible under poor lighting con-ditions. An optional liquid crystal display (LCD) is also available. Messages are displayed in English and do not require theaid of an instruction manual for deciphering. While the keypad and display are not actively being used, the display willdefault to defined messages. Any high priority event driven message will automatically override the default message andappear on the display.4.2.4 KEYPADDisplay messages are organized into ëpagesí under the following headings: Actual Values, Settings, Commands, and Tar-gets. The key navigates through these pages. Each heading page is broken down further into logical subgroups.The MESSAGE keys navigate through the subgroups. The VALUE keys scroll increment or decrementnumerical setting values when in programming mode. These keys also scroll through alphanumeric values in the text editmode. Alternatively, values may also be entered with the numeric keypad.The key initiates and advance to the next character in text edit mode or enters a decimal point. The key may bepressed at any time for context sensitive help messages. The key stores altered setting values.4.2.5 BREAKER CONTROLa) DESCRIPTIONThe L90 can interface with associated circuit breakers. In many cases the application monitors the state of the breaker,which can be presented on faceplate LEDs, along with a breaker trouble indication. Breaker operations can be manuallyinitiated from faceplate keypad or automatically initiated from a FlexLogicô operand. A setting is provided to assign namesto each breaker; this user-assigned name is used for the display of related flash messages. These features are provided fortwo breakers; the user may use only those portions of the design relevant to a single breaker, which must be breaker No. 1.For the following discussion it is assumed the SETTINGS !" SYSTEM SETUP !" BREAKERS ! BREAKER n ! BREAKER FUNC-TION setting is "Enabled" for each breaker.b) CONTROL MODE SELECTION AND MONITORINGInstallations may require that a breaker is operated in the three-pole only mode (3-Pole), or in the one and three-pole (1-Pole) mode, selected by setting. If the mode is selected as 3-pole, a single input tracks the breaker open or closed position.If the mode is selected as 1-Pole, all three breaker pole states must be input to the relay. These inputs must be in agree-ment to indicate the position of the breaker.For the following discussion it is assumed the SETTINGS !" SYSTEM SETUP !" BREAKERS ! BREAKER n !" BREAKERPUSH BUTTON CONTROL setting is "Enabled" for each breaker..c) USER KEY CONTROLAfter the 30 minute interval during which command functions are permitted after a correct command password, the usercannot open or close a breaker via the keypad. The following discussions begin from the not-permitted state.d) CONTROL OF TWO BREAKERSFor the following example setup, the symbol (Name) represents the user-programmed variable name.For this application (setup shown below), the relay is connected and programmed for both breaker No. 1 and breaker No. 2.The USER 1 key performs the selection of which breaker is to be operated by the USER 2 and USER 3 keys. The USER 2key is used to manually close the breaker and the USER 3 key is used to manually open the breaker.