Brahma 37201252 MPI22 control box

Brahma MPI22 37201252 gas firing device belongs to a series of devices based on microcontrollers designed to control forced-draft burners running on mixed oil and gas fuels with intermittent operation. The MPI22 is a new product that, in addition to performing all the standard functions of the burner, also includes a valve inspection system test program, activated on request. Connecting only one control unit instead of two represents a technical and economic advantage. These control elements carry out a non-volatile lock that allows the system to restart only through a manual reset of the control.

One of the features is the ability to control various types of air dampers, ensuring the versatility of the control unit and compliance with the operating cycle prescribed by the standards. The controller is suitable for use with multi-stage or modulating burners for domestic and industrial heating.

General characteristics

The features of Brahma MPI22 37201252 gas control unit include:

• Flame control using flame straightening (ionization) properties or UV1 type ultraviolet phototubes (technical specifications are specified in the relevant technical data sheets).

• Two independent safety contacts for controlling the gas valve.

• The service life of electrical equipment is more than 250,000 operations at the maximum declared load.

• Built-in and/or remote manual reset with liquid crystal indication of the reasons leading to an emergency shutdown.

• The ability to control the valve inspection system at the pre-purge stage or after purging.

• Easy to install and connect.

• The possibility of multiple ignition attempts depending on the end use.

• Operating cycles compatible with the LFL1 type controller (Siemens). When replacing the control unit, the outlet must also be replaced.

Technical specifications

Power supply: 230 V (+10%/-15%) – 50/ 60 Hz; on request: 110/120 V (+10%/-15%) – 50/ 60 Hz

Operating temperature range: -20°C + 60°C

Ambient humidity: no more than 95%

Degree of protection: IP40

Classification codes:

according to EN 298:03 FBLLXN

according to EN 230:05 FTLLXN ”WLE”

Power consumption at startup: 7.5 VA

Power consumption during operation: 9 VA

The presence of a base: no

Pre-ventilation time (TV/tp): 20 sec

Safety time (ts): 3 sec

Tightness control of gas valves: yes

Weight: 0.95 kg

Dimensions: 10.3×10.3×9.1 cm

Construction

The use of special manufacturing technology and the introduction of SMT technology ensure high flexibility of air flap control. The plastic housing protects the control panel from damage caused by emergencies, careless handling, as well as from dust and dirt. The built-in varistor prevents damage to the control panel during power surges.

Also, the built-in fuse protects the internal control relays in the event of a short circuit at the outputs (gas valves, motor, transformer and lock signal). Despite the presence of this fuse, it is recommended to use an external high-speed fuse corresponding to the connected loads and not exceeding 6.3 A to provide additional protection for the control unit.

Operating mode

When the thermostats R, W and GP are closed, the system starts the engine of the first burner (M1), and after the delay time (t7), also the second burner (M2). After the t16 delay, the air flap opens to the maximum air flow. After the air flap is fully opened, the system checks the APS air pressure switch; if the APS does not switch within time t10, the system is blocked. Otherwise, the cycle continues taking into account the pre-purge time (t1).

At the end of the pre-purge, the air flap is commanded to close to the minimum air flow, and the pre-ignition phase t3 (t3’) begins. If the control unit detects a flame signal at the pre-ignition stage, the system switches to safe time t2 (t2’), where power is supplied to the gas valve and the ignition transformer is maintained. If there is no flame signal, the control unit switches to lock mode.

The second valve is switched on with a delay of t4 after the first one, if there is a sufficient flame signal. The sequence ends after the delay t5 expires, when the air flap regulates the air flow through the external control LR. At startup, the position of the air flap is checked, then a command is given to close to the minimum air flow before the start of the pre-ignition time. This state is maintained until the end of the ignition sequence, then a modulation command is sent to the external LR device.

Patent/certification

− EC type certification (PIN code 0694BQ0913) in accordance with the Gas Appliance Directives 90/396 and 93/68;

− in accordance with the following standards:

− EN 298:03 (European standard for automatic ignition of gas burners and flame control systems);

− EN 676:03 (European standard for automatic forced-draft gas burners);

− EN 1643:00 (European standard for valve inspection systems);

− EN 267:99 (Forced draft oil burners);

− EN 746-1:97 (Industrial heat treatment equipment);

− EN 746-2:97 (Industrial heat treatment equipment);

− EN 230:05 (European standard for automatic flame control systems for oil burners).