Multifunctional Gas Control Valve BM 762. Safety and Control Combination

Transcription

1 Multifunctional Gas Control Valve BM 762 Safety and Control Combination 3.40 Description Multifunctional gas safety and control valve combination for fully automatic operation. One or two-step versions, with or without pilot gas rate. Fast or slow-opening with adjustable start gas rate. Constant governed main gas rate. Supply pressures up to max. 100 mbar. Application For gas boilers and gas-air heaters with atmospheric and fan-assisted burners. Suitable for gases in accordance to EN 437 and other neutral combustible gases. BM 762 CE-0085 AO 0334 EC Type Specification to EC Gas Appliance Directive. 1 6

2 Combinations Valve BM 762 Multifunctional Gas Control BM Controls Type Version BM (I)* BM (II)* BM (III)* BM (I)* BM (II)* BM (III)* * Versions I Start gas, main gas flow II Pilot gas, start gas, main gas flow III Step 1, main gas flow standard available on request not available alternatively Group A or B Description of main components Solenoids valvesmethods of operation Governor The governor (3) compensates pressure fluctuations in the mains and ensures a constant flow to the burner. Converter The governor is put out of operationby turning over the converter (5). The max. gas rate is then given by the burner injector. Slow opening If the control valve is to open slowly, the safety solenoid valve (7) is to be controlled in an way, that it opens approx. 5 sec. before the solenoid valve (6). The gas pressure acts on the governor diaphragm and the governor closes. When the solenoid valve (6) is opened the governor opens slowly. Solenoid valves The solenoid valves have DC coils which are protected against voltage peaks and equipped with interference suppression device. Versions available both in Class A and Class B and combinations. Filter/strainer A pilot gas filter (12) is installed in the internal gas supply line for the pilot flame; a main gas strainer (13) is installed at the gas inlet. The versions and are with a filter tested in accordance with DIN-DVGW for fan assisted gas burners. Pilot gas Restrictor The pilot gas flow is adjustable at the pilot gas restrictor screw (9). Pressure switch Acts as a safeguard against lack of gas monitoring the gas pressure on the inlet side. The pressure switch (8) is factory set and sealed to customers specifications. Method of operation (version 1) The solenoids can either be operated separately or simultaneously. The BM an BM have the options to have a side outlet to feed two separate main burners. Method of operation (version 2) The safety solenoid valve (7) serves as a pilot gas valve. By switching the control valve, the solenoid valve (7) opens and gas passes via the pilot outlet (16) to the burner. Electrical ignition fires the gas. The firing device monitors the flame and releases the flow of main gas via the solenoid valve (6). Method of operation (version 3) Two step operating is facilitated by separate control of solenoid valves (6) and (7). When opening solenoid valve (9) step 1 is initiated and the gas flows via a by-pass to the main gas outlet (15). Electrical ignition takes place direct by the main burner. Solenoid valve (6) does not open until step 2 is actuated by the control box. The flow rates of the two steps are separately adjustable. 2 6

3 Functional diagram BM / 014 Method of operation version Method of operation Fully automatic operation for atmospheric and fan-assisted gas burn ers. Control of mains flow by means of the governor, slow or fast opening. With two on-off operating solenoid valves can operate in three different versions depending on their connection to the control box Functional diagram BM / 014 Method of operation version 3 1. Simultaneous opening and closing for slow start see description "Description of main components" and "Solenoid valves methods of operation" Main gas Adjustable start gas rate optional 2. 2-step operation, pilot and main gas Adjustable start gas rate optional 3. 2-step operation, step 1 and main gas flow Optional incorporation of a gas pressure switch monitoring the minimum mains pressure

4 Solenoid valve - Method of operation BM and BM main flow start gas Method of operation 1 main flow start gas pilot gas Method of operation 2 main flow (stange 2) stange 1 time time Legend to functional diagrams 1 Control valve body 2 Cover 3 Governor 4 Governor compensating spring 5 Converter 6 On-off operating solenoid valve 7 Safety shut-off solenoid valve 8 Pressure switch 9 Pilot setting screw 10 Start gas setting screw 11 Main gas setting screw 12 Pilot gas filter 13 Main gas strainer 14 Main gas inlet 15 Main gas outlet 16 Pilot gas outlet 17 1st Step setting screw Method of operation 3 tim e Performance characteristics BM , BM (2 Class ) A Class B G Class B G Class A G Natural gas d 0,6 A Air d 1,0 8 A Class A 6 4 BM , BM Class A and filter 120 m BM , BM Class B and filter 120 m P 20 mbar burner pressure PBr mbar 4 6

5 Dimensions 127 Pilot gas connection M 10x M5 Rp 1/2 Rp 3/4 Installation The BM 762 multifunctional gas control valve is a safety device. Installation, adjustment and servicing may only be performed by qualified personnel and must conform with the requirements and codes of local authorities and the installing and adjustment instructions. Before starting the appliance it must be subjected to a security and tightness test. The max. permitted ambient temperature must not be exceeded. Consequently, the valve must not be exposed to direct radiation from the burner. During installation take care to keep the control free of burs, dirt or foreign matter. Electrical connections Use approved sealants only. Coils VAC Hz N L/P Electrical connections AMP male connector A6.3 x 0.8 mm Adjustment facilities Setting screw, max. capacity Converter Setting screw start by-pass Setting screw pilot gas Pressure test nipple Setting screw, max. capacity Setting screw, step 1 Pressure test nipple Version I, II III Version Pressure test nipple Pressure test nipple 5 6

6 Safety and Control Combination BM 762 Technical data Connections, inlet and outlet Internal pipe threads according to ISO 7/1 Alternatively with flange with pipe threads according to ISO 7/1 Pilot gas Supply pressure Governor range Max.flow Ambient temperature Solenoid valves (alternatively) Group Governor Degree of protection Opening time Closing time On period System frequency Current input/coil Cable connection Pressure switch Installation position Rp 1/2 or Rp 3/4 Rp 1/2 or Rp M10 x 1 / Ø 6 mm - Ø 4 mm 1/4 o.d. max. 100 mbar 2.5 mbar - 20 mbar 3.80 m 3 /h (air) at p 2.5 mbar 0 C to + 70 C Group A or B as per EN Class 2 IP 40 IEC 529 Fast-opening < 1 s Slow-opening < 10 s < 1 s 100% ~(AC) Hz 24 V +10 % 15 % ~(AC) Hz 110 V +10 % 15 % ~(AC) Hz 220 V +10 % 15 % ~(AC) Hz 240 V +10 % 15 % 0.25 A : 24 V 0.08 A : 110 V 0.04 A : 220 V AMP 6.3 x 0.8 mm Lower operating pressure factory set, optional: 3.5 mbar, 7 mbar, 10 mbar, 13 mbar, 38 mbar Multipositional We reserve to make any changes in the interest of technical progress. 6 6