Brahma 30021785 CM31 control box

The Brahma CM31 30021785 control units 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.

CM31 30021785 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

1. The CM31 30021785 gas control unit provides durable protection against mechanical damage such as shocks and impacts. This is achieved thanks to the plastic housing and self-extinguishing material.

2. The case is effectively protected from external factors, including dust and dirt, which contributes to the durability and reliability of the device.

3. Designed with safety and durability in mind, this enclosure aims to minimize the risks associated with exposure from the external environment.

4. To optimize the dimensions of the printed circuit board, a module with electronic components placed on the surface was used.

5. This led not only to a reduction in the size of the device, but also to an increase in its efficiency.

Connection

1. Ease of connection of controllers:

– The possibility of using one-way quick-release connectors facilitates the connection process.

   – The simplicity and reliability of the connection is ensured thanks to the quick-release connectors.

2. Easy installation:

– Non-reversible connectors with a different number of poles simplify the installation of controllers.

   – A more convenient installation is made possible by a variety of quick-release connectors.

3. Efficient connection of ignition and detection electrodes:

– Quick-release connectors of various sizes are provided for ignition and detection electrodes.

   – Easy replacement and installation of electrodes is provided due to the variety of connector sizes.

4. Flexibility of the ignition device:

– The ignition device with two outputs allows you to generate a spark at different points or between isolated electrodes.

5. Safety and reliability of controller connection:

– It is important to take into account voltage relief when connecting controllers.

   – The presence of a sufficient number of terminals for grounding and neutral ensures the safety and reliability of the connection.

6. Flexible controller layout:

   – The controllers can be either integrated into the device or located in external connection boxes, which gives additional flexibility in placement.

The principle of operation

1. Self-monitoring when turned on:

– Each time the controller is turned on, it performs self-monitoring of all its components.

2. Pre-purge and check of the flame signal amplifier (TW):

– During the pre-purge or standby period (TW), the internal circuit of the controller checks the operation of the flame signal amplifier.

   – If a parasitic flame signal or an amplifier malfunction is detected, the controller locks and does not start.

3. Fan control and air pressure switch contact check:

– In models with fan control, before pre-purging, the controller checks the state of the air pressure switch contact, making sure that there is no air flow.

   – Only when the test is successful, the fan is activated and pre-purging begins when the pressure switch is switched to the “air flow” position.

4. Starting the gas valve and ignition device (TS):

   – After the waiting time or pre-purge has expired, power is supplied to the gas valve.

   – The ignition device receives voltage by triggering the safety time (TS).

5. Blocking when a flame is detected:

– If a flame is detected during a safe time, the ignition device is blocked.

   – In models with the corresponding function, an independent auxiliary contact is switched, indicating flame detection.

6. Blocking mode in the absence of flame:

   – 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.