Brahma UV cell 1

PHOTOTUBES TYPE UV1 UV2 UV3 FLAME SENSOR FOR GAS BURNER INTRODUCTION Flame detection in burners occurs by means of sensors detecting the presence of flame through an electrical signal, which can be used by ignition and control devices. UV phototubes exploit ultra-violet radiation emitted by the light generated by the flame; they are especially suitable for appliances in which very dissimilar fuels (e.g. liquid and gaseous fuels) are used. UV1 FEATURES These sensors are used for flame detection in gas and mixed fuel (gas and oil) burners. UV phototubes consist of a glass bulb filled with gas, containing two electrodes suitably shaped. When supplying both electrodes with AC voltage, if an ultra-violet electromagnetic radiation (range from 190 to 290 nm) hits the phototube, the electrons, emitted by the negative biased electrode and captured by the positive biased one, start an ionization process leading to the generation of an electric discharge and hence to the UV2 production of electric current. UV1, UV2 and UV3 are the available phototube models; their features and dimensions are explained below. PHOTOTUBE TYPE UV1 Phototubes type UV1 are available in different sensitivity: - Standard sensitivity - /A : medium sensitivity - /H : high sensitivity UV3 The standard cable length is 655 mm, but versions with longer cables are available. Ø22 85 PHOTOTUBE TYPE UV2 Phototube type UV2 are smaller than phototube type UV1 (the length and the diameter of the case are smaller). The standard cable length is 655 mm, but versions with longer cables are available. Ø17 76 4068_r04 1/2  PHOTOTUBE TYPE UV3 CONNECTION The length and the superficial treatment of the case are The blue wire is marked with number 8 because it must be the differences between the UV3 and UV1 models. The connected to terminal 8 in Brahma devices series MF2, case’s superficial treatment consists of a chromium MF2.4, SR3/TR and M300 and to terminal 21 in Brahma plating. device type MPI; Brown wire must be connected to the The UV3 phototube has no cable which is supplied as an earth. accessory (see fig. 1). In Brahma device type RE3 the blue wire must be Models different for the sensitivity are available upon connected to the terminal number 3 and the brown wire to request: the terminal number 4. - Standard sensitivity - /A : medium sensitivity DIRECTIONS FOR INSTALLATION - /H : high sensitivity - Respect the applicable national and European standards EN 60335-1 and EN 60335-2-102 related to the electrical safety; Ø22 - Avoid placing detection cable close to power and ignition cables; - In order to avoid problems due to the obsolescence of the detecting element , we recommend replacing it 80 after about 10.000 operating hours. These flame sensors are not sensitive to the daylight, therefore if they are near to neon glow lamps or similar they need of particular screening for not to be influenced. - Avoid subjecting the device to strong stress, impacts or falls TECHNICAL DATA Fig. 1 Nominal life time: 10.000 hours (*) Maximum distance from UV source: 1m UV1-3 sensor temperature range: -20 ÷ +50 °C (*) UV2 sensor temperature range: -20 ÷ +60 °C The Fig. 2 shows the UV1, UV2 and UV3 drilling plane. (*) UV1 and UV3 phototubes can operating also at temperature higher than + 50°C, in this case the se nsor life Per UV1 e UV3 Per UV2 time will be less than the 10.000 nominal hours. 22.5 17.5 REPLACING THE SENSING ELEMENT IN PHOTOTUBES TYPE UV1 AND UV3: In these types of phototubes, the sensing element can be 18.5 18.5 17 17 replaced by simply pulling it out of the casing top opening. 37 34 The new sensing element should be inserted into the Fig. 2 casing in the direction shown in the following figure: Phototube insertion direction Window ATTENTION -> Company Brahma S.p.A. declines any responsibility for any damage resulting from the Customer’s interfering with the device BRAHMA SpA Via del Pontiere,31 37045 Legnago (Vr) Tel. +39 0442 635211 – Telefax +39 0442 25683 2010/12/23 Subject to amendments without notice http:// www.brahma.it E – mail: brahma @ brahma.it 2/2 4068_r04