MHG 262
MHG 262i
Optical smoke detector with extended spectrum of detected smokes and with isolator
Optical smoke detector with extended spectrum of detected smokes and with isolator

Optical smoke detector with extended spectrum of detected smokes and with isolator is intended for the automatic fire alarm signalling as a smoke detector in the analogue
and addressable Fire Detection and Fire Alarm System LITES.

Type MHG 262 does not contain isolator.

It responds to both visible and invisible smoke particles (aerosols) on the principle of detection of scattered infrared radiation.

The MHG 262i (MHG 262) detector is intended for co-operation with the analogue Control and Indicating Equipments (C.I.E.) MHU 110, MHU 111, MHU 115, MHU 116, MHU 117 and with the addressable C.I.E. MHU 109. The detector contains a program that evaluates the fire situation pursuant to measuring of the surrounding smoke concentration, namely in agreement with the following adjustable characteristics:

  • basic sensitivity of the detector; it monitors the surrounding smoke concentration increase compared to the quiescent state, that compensates the climatic and other influences (environs temperature, pressure etc.) continuously; the basic sensitivity can be adjusted in eight degrees that must be selected with reference to the detector’s combustion gas load that the detector responds to; the basic sensitivity can be inactivated completely, or it can be set only partial.
  • reaction time; the verification level of the fire situation is concerned; also adjustable in eight degrees, however they can’t be expressed by a simple time stamp, because the reaction
    time depends on the time progression of the fire situation
  • dustiness watch; it monitors the rest level of the detector, and upon this it evaluates the dustiness rate of the optical chamber and consequently the reliability of the detector; it can
    be adjusted in seven degrees, or inactivated; it’s set in reference to the dust nuisance rate round the detector and to the setting of other parameters

Further the pre-alarm sensitivity can be adjusted, it is always higher then the alarm sensitivity. The detector self regulates its internal working characteristics, if they don’t reply to the allowable tolerance, fault warnings occur.

The adjustable characteristics can be set either into a configuration program and recorded to the detector through the C.I.E. or they can be programmed right by means of the preparation MHY 535.

The detector MHG 262i has a built-in isolator (type MHG 262 does not contain isolator), that in case of a short-circuit separates the shortcut part between detectors with connected isolators on the circle line. The detector is installed into the MHY 734 Base. For installation it is possible to use the Mounting Bar MHY 736.

The detector fulfils the requirements of the standard ČSN EN 54-7 and is certified for use in the Fire Detection and Fire Alarm System according to law No. 22/1997 Sb., in wording law No.
71/2000 Sb. in EVPÚ Dubnica nad Váhom NB 1293 and relevant Government regulations.


Technical parameters
Power supply addressable C.I.E. LITES
Optical signalling a couple of red LED
Parallel signalling type LITES
Testing test bar MHY 506, test from the C.I.E.
Protection according to ČSN EN 60529 IP 43
Radio screening degree according to ČSN EN 55 022 B-class equipment
Address setting Addressing Preparation MHY 535 in the range 1 ÷ 128
Dimensions (Ø98 × 42) mm
Weight around 140 g


Product is intended for operation with safe equipment in sense of ČSN EN 60950.

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 °C až +70 °C
max. relative humidity 95 % při 40 °C
without condensation and ice accretion  
Z: special conditions 3Z1 heat radiation negligible
3Z8 irrigation water
B: biological conditions 3B1 without presence of flora and fauna
C: chemical active substances 3C2
S: mechanical active substances 3S1
M: mechanical conditions 3M2
Duration of significant temperature (45°C ÷ 70°C) 2 months/year
Duration of significant humidity (85 % ÷ 95 % / ≤ 40°C) 100 hours/year
Maxium duration of spraying 10 min/month