MHG 943
MHG 943
Fourfold input element (technological detector)
MHG 943 is an addressable input element with four inputs intended in cooperation with addressable C.I.Es Lites

MHG 943 is an addressable input element with four inputs intended in cooperation with addressable C.I.Es Lites for automatic signalling of user defined exceptional state(s) of any
external device, which indicates this state either by closing or opening an electrical contact or by voltage received on the optoisolated input. Contacts can also be set as guarded.

The element communicates with C.I.E. on 4 consecutive addresses. The first one is set by the addressing preparation MHY 535. Activation of any input is signalled by blinking of a red LED and additional SMD LED of appropriate input. The element consists of printed circuit board with terminal blocks which is placed in a plastic box with removable transparent cover.

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 contact. These inputs can as well be set 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., refers under appropriate address and sends information about input activation to the C.I.E.



MHG 943 zapojení

Technical parameters
Power supply (18 to 21) Vimp
Rated voltage 12 Vimp
Standby current max. 200 μA
Number of inputs 4
Optoisolated input – current
input voltage 9 V ÷ 30 V (logical 1), 0 V ÷ 3 V (logical 0)
input resistance cca 10 kΩ
Input contact closing/opening
resistance of line 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
Input contact guarded
Test voltage 12 Vimp
Line resistance max. 100 Ω
test current standby cca 0,8 mAimp
test current FIRE cca 1,5 mAimp
test current FAULT cca 0,5 mAimp
resistance standby 10 kΩ
resistance FIRE 4,7 kΩ
resistance FAULT 20 kΩ
Optical signalling red LED
Address range (by indicating preparation MHY 535) 1 – 128
Parallel signalling line resistance max. 100 Ω
Protection according to ČSN EN 60529 IP 65
Radio screening degree according to ČSN EN 55022 B-class equipment
Cross-section of connectable wires (0,2 ÷ 1,5) mm²
Dimensions (w × h × d) (130 × 941 × 57) mm
Weight cca 220 g


Product is intended for operation with safe equipment in sense of ČSN EN 60950 and meets the requirements of input/output device ČSN EN 54-18.

When designing the detector must heed the recommendations and measures to reduce the impact of interference voltages and regulations for projection fire detection and fire alarm systems C.I.E.s.

Working conditions
Application of the detector is in areas protected against weather conditions with classification according to ČSN EN 60721-3-3.
K: climatic conditions for environment 3K5
working temperature range (-25 to +70) °C
max. relative humidity max. 95 % at +40 °C
atmospheric pressure range (86 až 106) kPa
without condensation and ice accretion  
Z: special conditions 3Z1 heat radiation negligible
B: biological conditions 3B1 without presence of flora and fauna
C: chemical active substances 3C1
S: mechanical active substances 3S1
M: mechanical conditions 3M1
Duration of significant temperature (45°C ÷ 70°C) 2 months/year
Duration of significant humidity (85 % ÷ 95 % / ≤ 40°C) 100 hours/year