Sirena Loud Speaker

Sirena siren speaker: technical overview

The Sirena SE 4/25 L PLC is an acoustic signalling device from the ELECTRA product family, with product code 50414 and CE marking. It can be used for general signalling and for warning of imminent danger in industrial and civil applications. The model provides a fixed continuous signal, is not multi-tone, and its sound level cannot be adjusted. It provides one alarm level with a nominal 24 V DC power supply.

What does the single-tone design of the Sirena acoustic signalling device mean?

The SE 4/25 L PLC emits a linear continuous tone at a frequency of 1000 Hz. It does not have a tone-selection dip-switch because the model does not provide multiple tone patterns. The sound level is also not adjustable, so system planning must be based on one alarm level and a maximum sound pressure level of 93 dB(A).

How does the Sirena SE 4/25 L PLC electronic siren operate?

The sound is generated by a 4 W magnetodynamic unit. The terminal assignment is fixed: terminal 1 is the positive power supply, terminal 2 is the PLC +24 V DC control signal, and terminal 3 is the negative power supply. The power supply line must be protected with a fuse rated for the voltage, and installation must be carried out by qualified personnel.

Connection terminals of the Sirena industrial siren

• Terminal 1: positive power supply conductor.
• Terminal 2: PLC control with a +24 V DC signal.
• Terminal 3: negative power supply conductor.
• Power supply line protection: fuse rated for the voltage.
• Installation: must be carried out by qualified personnel.

Before connection, the 24 V DC power supply, polarity, and PLC output signal must be checked. The device is specified for continuous duty.

Power supply, electrical data, and PLC application

The operating voltage is 24 V DC with a permitted tolerance of +/-10 percent, while the nominal current consumption is 120 mA. The electrical safety classification is Class 2, and the duty cycle is continuous. The specified frequency is 50/60 Hz. Product code 50414 corresponds to the 24 V DC version.

What type of emergency warning system can use PLC control?

The device can be used for general signalling and for warning of imminent danger in industrial or civil applications. The PLC activates one continuous tone, so the control system cannot be based on multiple locally selectable tones or adjustable volume.

What acoustic characteristics does the Sirena signalling device provide?

The maximum sound pressure level is 93 dB(A) at a distance of 1 m. The 4 W magnetodynamic unit generates a linear continuous tone at a frequency of 1000 Hz. The number of tones is one, the tone type is continuous, and the sound level is not adjustable. The device does not provide multi-tone selection, volume control, or tone ramp-up time adjustment.

Warning signal with a fixed 1000 Hz frequency

The continuous signal remains active while the control system operates the siren. Because the sound level is not adjustable, system planning must use the specified value of 93 dB(A) at 1 m.

Mechanical construction, IP30 protection, and mounting

The device housing is made of self-extinguishing ABS. The base is grey and has a flat design. The overall dimensions are 100 x 100 x 57.5 mm, the mounting-hole spacing is 74 x 74 mm, and the hole diameter is 5 mm. Installation is carried out using standard screws, but the screws must be supplied separately.

Is the IP30 version specified as an outdoor signalling device?

The degree of protection is IP30, and the operating temperature range is from -30 to +50 C. The device has IP30 protection. Outdoor application is not specified, so the installation environment must comply with the IP30 classification.

What signalling tasks is the Sirena industrial siren designed for?

The SE 4/25 L PLC is an electronic siren designed for industrial applications. In industrial and civil use, it can provide general signalling and warn of imminent danger. It communicates an acoustic status using one continuous tone and can therefore be used where there is no requirement to distinguish between multiple tone patterns.

Alarm speaker or electronic siren?

The technical designation of the product is electronic siren, and its sound-generating component is a 4 W magnetodynamic unit. The device is not a general-purpose audio loudspeaker. It is not designed to reproduce speech or variable audio signals, but to generate a fixed continuous 1000 Hz signal.

Documented features of the Sirena siren speaker

• Separate PLC +24 V DC control terminal.
• Continuous duty cycle.
• Fixed continuous tone at a frequency of 1000 Hz.
• Maximum sound pressure level of 93 dB(A) at 1 m.
• 4 W magnetodynamic unit.
• Self-extinguishing ABS housing and Class 2 classification.
• Operating temperature from -30 to +50 C.

The limitations must also be compared with the requirements of the intended signalling task.

What limitations must be considered?

• Only one non-adjustable tone is available.
• The tone frequency is fixed at 1000 Hz.
• The degree of protection is IP30.
• Outdoor application is not specified.
• The mounting screws are not included in the delivery.
• The power supply is limited to the 24 V DC version.

The device can be selected for applications where one continuous tone is required and the environment complies with the IP30 classification.

What should be checked when selecting a Sirena siren speaker?

First, the 24 V DC +/-10 percent power supply, the 120 mA current consumption, and the +24 V DC PLC control signal must be checked. Next, the single continuous 1000 Hz tone and the 93 dB(A) sound pressure level at 1 m must be compared with the application requirements. Finally, the IP30 degree of protection, the operating temperature range from -30 to +50 C, and the dimensions of 100 x 100 x 57.5 mm must be verified.