Unit of outputs MHY 918 is a device intended for control of external devices on serial line RS 485 in Fire Detection and Fire Alarm System Lites with C.I.E. MHU 109, MHU 110/111, MHU 113, MHU 115 and MHU 116/117.
Outputs are type open collector and are intended for control of external devices (siren, beacon etc.) or for control of additional relays. For smaller switched power it is possible to attach each pair of open collectors with 6XK 199 722 module with two relay contacts, or use single relay placed by the external device. Each output of type open collector can be set to guard a short-circuit and line interruption. Unit of outputs contains 8 outputs. Seven outputs are user definable, eighth serves as an output for system fault and is normally activated. This output cannot be defined by the user.
In the special setting of C.I.E. Output of state the unit allows automatic activation of outputs based on actual C.I.E. state.
Unit of outputs is equipped with a short-circuit isolator for line RS 485.
Unit of outputs is a printed circuit board with terminal blocks placed in a plastic box with a lid and with pre-moulded holes designed for mounting cable glands.
Unit of outputs is supplied in two variants that differ by outputs attachment:
- MHY 918/K - 8 output connectors CF 5,08/2 used as open collectors (for example as unit of guarded serial outputs for siren).
- MHY 918/R - 4 modules 6XK 199 722 with two relays as a voltage-free changeover contact (for example as a direct replacement of Unit of outputs MHY 907).
Outputs type open collector and type with modules can be combined as needed. Unit of outputs and connected external devices can be powered:
- from connected C.I.E.
- from external backup source – must be used in case when the unit of outputs powers external devices and voltage drop on wiring is higher than technical parameters permit, or when consumption of all connected devices is higher than 0,5 A.
Capacity of each output is 0,3 A while count of all currents is max. 0,5 A when powered from C.I.E. or max. 2 A when powered from external source.
Unit of outputs and connected devices can be powered from C.I.E., external source or the connected device can have it’s own power supply.
These combinations are allowed:
- Unit of outputs and connected devices are powered from C.I.E.
- Unit of outputs is powered from C.I.E. and connected devices from external source
- Unit of outputs and connected devices are powered from external source
- Unit of outputs is powered from C.I.E. and connected device has it’s own power supply
- Unit of outputs is powered from C.I.E. and connected device is controlled with a relay
