MHY 925 is an addressable multiple input/output element, containing 8 (4) programmable inputs and 8 (4) programmable outputs. It connects to a detection line of Fire Detection and Fire Alarm System LITES, eventually on communication line SL-RS 485 of C.I.E. MHU 115. The element contains an isolator.
Inputs serve to automatic signalling of user defined states of any external device, which indicates this state either by closing or opening an electrical contact or by voltage received by the optoisolated input. Contacts can also be set as guarded.
Outputs serve to control of external devices connected to NO or NC relay contacts. MHY 925 is produced in two variants:
a) MHY 925/4 – contains 4 programmable inputs and outputs
b) MHY 925/8 – contains 8 programmable inputs and outputs
Properties of each input, conditions for activation and properties of each output are defined via the configuration program for C.I.E.s.
Electrical circuits are on a printed circuit board which is placed in a plastic box with removable cover. Connecting wires are connected to plug-in screw terminal blocks.
The element is powered by a pulse voltage from the detection line of C.I.E. It contains power supply for its own electronic circuits. Evaluation circuits of input can be set as optoisolated or for connection of switching or breaking contact. These inputs can be set as well as guarded, where with the external device an opening (FAULT) or closing (ALARM) contacts can be connected simultaneously. At the same time the loop is guarded for interruption or a short-circuit.
Addressable part registers the communication from C.I.E., reports under appropriate address and sends information about input activation to the C.I.E.
|Power supply||(18 ÷ 21) Vimp|
|Stand-by current||max. 200 μA|
|Number of outputs||4 or 8|
|Input optoisolated – voltage|
|input voltage||9 – 30 V (logical 1), 0 – 3V (logical 0)|
|input resistance||cca 10 kΩ|
|Input NO/NC contact|
|resistance of wire and closed contact||max. 1 kΩ|
|resistance of open contact||min. 10 kΩ|
|output test voltage||cca 12 Vimp|
|output test current (closed contact)||max. 1,2 mA|
|test voltage||12 Vimp|
|line resistance||max. 100 Ω|
|stand-by test current||cca 0,8 mAimp|
|alarm test current||cca 1,5 mAimp|
|fault test current||cca 0,5 mAimp|
|stand-by resistance||10 kΩ|
|alarm resistance||4,7 kΩ|
|fault resistance||20 kΩ|
|Number of outputs||4 or 8|
|Maximal switching current||1 A|
|Maximal switching voltage||48 V|
|Maximal switching power||30 Wss> / 40 VAst|
|Usable for electricity grid||no|
|Optical signalling||red and yellow LED|
|Address adjustment (via MHY 535)||1 to 128|
|Protection according to ČSN 60529||IP 54|
|Radio screening degree according to ČSN 55022||B-class equipment|
|Cross-section of connectable wires||(0,2 až 1,5) mm2|
|Dimensions||(š × v × h) (254 × 180 × 63) mm|
|Weight||cca 600 g|