DESCRIPTION SPECIFICATION The Model 541 Protection Expansion/Annunciator is designed to be used as either a protection expansion module or as an annunciator or a combination of both. The inputs are fully configurable by the user to suit the application. The module features a number of facilities enabling it to be used as a stand alone module or part of a complex control system. It is particularly suited to providing input expansion to the DSE 500 series control modules. The safety on timer can be selected to be either internal from the fuel on input being active, or externally fed from another device such as the 520 Automatic start module. An alarm reset input is provided to enable the alarms to be cleared, this can be configured to be fed from either plant negative or plant positive DC. This gives maximum flexibility to the module, and allows for interfacing with an output relay on a 520 to enable the 520 module control switch to be the master alarm clear control. The module also features plant DC supply monitoring alarms and can provide indication of a high or low supply voltage. This feature can be disabled if not required. Alterations to the system are made by using a PC and the 808 interface. This also provides the operator with real time diagnostic facilities to monitor the operation of the system. Relay outputs are provided for by way of six configurable outputs. Normally the relays are configured as Warning, shutdown, electrical trip and common alarm outputs. The remaining two relays are configured to signal starting and delayed alarms active. However the relay function is configurable to activate on a range of functions, conditions or alarms. Relays 1&2 outputs are at negative plant supply to give compatibility with the inputs to other 500 series modules, relays 3 to 6 are the voltage free type. Additionally the module can be fitted to the 157 relay expansion module to provide a further eight fully configurable volt free relay outputs. Configurable inputs are available for Fuel, Safety on, Reset and Lamp test. This allows the module to function with N/O or N/C switches. Ten fully configurable auxiliary inputs are provided to give protection expansion or annunciator. These can be selected to be indication, warning, shutdown or electrical trip inputs either immediate, on start-up or held off during safety on delay. Uncommitted LED’s allow annunciation with configurable colour selection – each LED provides choice of Red, Green or Amber. Indication or warnings displayed steady, Shutdown or Electrical trip display Flashing.