Brahma 37056002 CM31U control box

Brahma CM31U 37056002 controllers are designed for efficient control of atmospheric gas burners with a fan, regardless of the presence in the combustion circuit. It can be equipped with a non-volatile or volatile lock: in the first variant, restarting after an emergency lock requires manual intervention, in the second – restoring the controller is possible only through a break in the supply and restoration of power supply.

The CM31U 37056002 control box find their application in various devices such as steam convectors, heating boilers, warm air generators, radiator tubular heaters and water heaters. The flame detection mechanism uses the ionization property without having a protective resistance, which makes contact with the detection electrode unsafe.

Features

• Flame control based on the rectifying properties of the flame (ionization);

• Two independent safety contacts in series at the outlet of the gas valve (models with manual reset);

• Service life of electrical equipment at max. declared load > 250,000 operations;

• Built-in fully solid-state ignition device with high efficiency;

• EU certification type (CE PIN code 0694BR1154) in accordance with Directive 90/396 on gas appliances and the following amendment to Directive 93/68;

• In accordance with EN 298 (European standard for automatic programming and flame control systems for gas burners);

• Auxiliary contact for low-power ignition or control of the main gas valve in intermittent power control systems (this contact is not isolated from the main supply voltage by reinforced insulation, therefore the relay contact is not suitable for controlling SELV circuits

• Manual reset

• Single flame

• Atmospheric with a fan

Complies with EN298:1993

• Complies with EN298:2003 (2)

• Classification code according to EN 298 (3) FMCLXN

Technical specifications

Power supply: 230 V – 50/60 Hz; on request: 110-120 V – 50/60 Hz

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

Humidity: max. 95 % at 40 °C

Degree of protection: IP00

Response time in case of flame failure: ≤ 1 s

Minimum ionization current: 1.2 µA

On request: 0.5 µA

Recommended ionization current: 3-5 times the minimum ionization current

Maximum cable length: 1m

Maximum parasitic electrode capacitance: ≤ 1 NF

Maximum short-circuit current: < 200mA AC

Maximum ionization current (230 V 50 Hz): 8 µA DC

Ignition voltage: 20 kV at 30 pF load

Spark repetition rate: 25 Hz

Maximum cable length: 2 m

Recommended discharge distance: 2-4mm

Power consumption: 2.5 VA

Spark energy: 15 MJ

Weight: 200 g

Construction

The CM31U 37056002 gas control unit provides durable protection against mechanical damage, such as impacts and impacts, thanks to a plastic housing and self-extinguishing material. It is also effectively protected from external factors, including dust and dirt. Designed with safety and durability in mind, this enclosure aims to minimize the risks associated with exposure from the external environment.

To optimize the dimensions of the printed circuit board, a module with electronic components placed on the surface was used. This led not only to a reduction in the size of the device, but also to an increase in its efficiency.

Connection

Connecting controllers becomes an easy process thanks to one-way quick-release connectors, ensuring simplicity and reliability of the connection. Non-reversible connectors with a different number of poles simplify installation, making it more convenient. Quick-release connectors of various sizes are provided for the ignition and detection electrodes, which ensures easy replacement and installation. An ignition device with two outputs allows you to generate a spark at different points or between isolated electrodes. It is important to take into account the voltage relief and the presence of a sufficient number of terminals for grounding and neutral when connecting controllers, which can be either built into the device or located in external junction boxes.

The principle of operation

Each time it is turned on, the controller performs self-monitoring of all its components. During the pre-purge or standby (TW) period, the internal circuit checks the operation of the flame signal amplifier. If a parasitic flame signal or an amplifier malfunction is detected, the controller is blocked and does not start. In fan-controlled models, before pre-purging, the controller checks the contact status of the air pressure switch, making sure that there is no air flow. Only with a successful test, the fan is activated and pre-purging begins when the pressure switch is switched to the “air flow” position. After the waiting time or pre-purge expires, power is supplied to the gas valve, and the ignition device receives voltage, triggering the safety time (TS). If a flame is detected within a safe time, the ignition device is blocked. In models with the corresponding function, an independent auxiliary contact is switched, indicating flame detection. If there is no flame after the safe time has elapsed, the controller switches to lock mode, turning off the gas valve and the ignition device.