Brahma 37201254 MPI22 control box

Brahma MPI22 37201254 relay belongs to a series of devices based on microcontrollers and is designed to control forced-draft burners using 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 is a technical and economic advantage. These control elements provide a non-volatile lock that allows the system to be restarted 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 37201254 control unit include:

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

2. Two independent safety contacts for controlling the gas valve.

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

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

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

6. Easy to install and connect.

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

8. 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): 36 sec

Safety time (ts): 2 sec

Tightness control of gas valves: yes

Weight: 0.95 kg

Dimensions: 10.3×10.3×9.1 cm

Construction

The use of SMT technology and a special plastic housing provide flexibility in controlling the air flap and protection from damage caused by accidents, careless handling, dust and dirt. The built-in varistor prevents damage during power surges. A fuse inside the unit protects the control relay from short circuits at the outputs (gas valves, motor, transformer, lock signal). It is also recommended to use an external fuse up to 6.3 A for additional protection.

Operating mode

When the thermostats R, W and GP are closed, the first burner (M1) starts, and after the delay t7, the second burner (M2) starts. After the t16 delay, the air flap opens completely. The system then checks the APS air pressure switch: when it is switched during time t10, the pre-purge process (t1) begins.

After pre-purging, the air flap closes to a minimum flow, and pre-ignition t3 (t3’) begins. When a flame is detected, the system switches to safe time t2 (t2’), power is supplied to the gas valve and the ignition transformer is maintained. In the absence of a flame, the system switches to lock mode.

The second valve is activated with a delay of t4 after the first one, if there is a flame signal. The sequence ends at the expiration of t5, when the air flap regulates the air flow through the LR control. Before pre-ignition, the position of the air damper is checked, then it closes to a minimum flow. This state is maintained until the end of the ignition sequence, after which the 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).