Electrical cabinets contain power supplies, terminals, cables, relays, control components and other electrical devices that may generate heat during operation. Loose connections, overloaded circuits, insulation damage or component failure can produce smoke before the condition becomes visible outside the cabinet.
In many projects, the electrical cabinet already has a 120VAC power supply, but there is no conventional 24V fire alarm circuit inside or near the equipment. Installing a complete fire alarm control panel, power supply and detector loop for one cabinet or a small number of monitoring points may be unnecessarily complicated.
The ANWETECH AT-S234 provides a practical solution for these applications. It is a standalone AC-powered photoelectric smoke alarm with a standard audible alarm, adjustable smoke sensitivity and one selectable NO/NC relay output.
The AC120V and AC220V models are separate versions and must be specified when ordering. The product is not a universal wide-voltage detector.
A room may already have ceiling-mounted smoke detectors, but smoke generated inside an electrical cabinet may remain within the enclosure during the early stage of an electrical fault.
Cabinet doors, internal partitions, cooling arrangements and equipment layout may delay the movement of smoke into the surrounding room. A detector installed inside or close to the protected equipment can monitor the local space nearer to the possible smoke source.
The AT-S234 is suitable for indoor smoke monitoring applications such as:
The detector is intended to detect visible smoke produced by slow smoldering fires or open flaming fires. It uses an infrared photoelectric sensing chamber and is not a gas detector or aspirating smoke detection system.
Many conventional fire alarm detectors operate from a 24VDC detector circuit connected to a fire alarm control panel. This arrangement is suitable for complete building fire alarm systems, but it may not be the most practical choice for every independent cabinet or equipment enclosure.
A 120VAC smoke alarm may be selected when:
The AT-S234 AC120V version uses an AC110V design that permits AC120V input.
The AC120V and AC220V versions must be ordered separately. Installers must confirm the voltage marked on the product before connecting the power supply.
The relay contact capacity remains the same for both voltage versions.
The AT-S234 is a non-addressable smoke alarm. It does not require an addressable fire alarm loop and does not provide an individual address to a fire alarm control panel.
During normal monitoring, the green indicator flashes. When smoke is detected, the red indicator remains illuminated and the audible alarm operates.
Depending on the selected reset mode, the detector can be configured for:
The required reset mode is selected through the internal switch.
This standalone arrangement is useful when the customer needs local smoke monitoring without installing a complete addressable fire alarm system.
The standard AT-S234 configuration includes an audible alarm.
When smoke is detected, personnel near the cabinet or protected equipment can receive an immediate local warning through the detector sounder and red alarm indication.
The stated alarm sound level is at least 80 dB.
The audible alarm is especially useful in:
However, a local sounder may not be sufficient for an unattended cabinet or remote equipment room. For this reason, the detector also provides a relay contact output.
The AT-S234 provides one relay output group with:
An internal selector or DIP switch allows the installer to choose either normally open or normally closed contact operation.
The confirmed relay contact parameters are:
The detector supply voltage and the relay contact rating are two different electrical parameters.
For example, the AC120V detector version is powered by 120VAC, but its relay contact can still switch within the confirmed maximum contact ratings. This does not mean that the detector itself accepts a universal AC120V to AC220V power supply.
The relay output allows the AT-S234 to provide a switching contact signal to a compatible external input circuit.
A typical signal sequence is:
AT-S234 detects smoke or a product fault
→ The selected NO/NC relay contact changes state
→ An intermediate relay, PLC input, BMS input or compatible control circuit receives the signal
→ The external control system performs the required project action
Depending on the external control design, the signal may be used as a condition for:
The AT-S234 itself provides the detection and contact signal. The actual equipment action must be performed by the external control circuit.
Fans, motors, solenoid valves and other electrical loads may have high starting current or inductive characteristics. These loads should not automatically be assumed to be suitable for direct connection to the detector relay.
A safer engineering arrangement is:
AT-S234 relay contact
→ Intermediate relay or contactor coil
→ External power or control circuit
→ Controlled equipment
The intermediate relay or contactor separates the smoke detector contact from the final load and allows the control components to be selected according to:
The intermediate relay, contactor and external protection devices must be selected by the project electrical engineer.
The 5A rating is the maximum confirmed contact current. It should not be interpreted as permission to connect every type of 5A load directly to the detector.
The AT-S234 does not provide separate alarm and fault relay contacts.
Smoke alarm and product fault conditions share the same relay output group. Therefore, an external system receiving only this contact signal cannot independently identify whether the state change was caused by smoke or by a detector fault.
This arrangement is suitable when the project only requires a general alarm or abnormal-condition contact.
The product may not be suitable when the project specification requires:
This limitation should be confirmed during system design.
The AT-S234 includes an onboard smoke-sensitivity adjustment switch.
The standard factory setting is:
1 dB/m
The ability to adjust sensitivity is useful because installation environments can differ in terms of:
Sensitivity should not be adjusted without testing. After changing the setting, the detector should be tested using approved test smoke or a suitable smoke test chamber.
The exact adjustment should be determined according to the application environment and project requirements.
The AT-S234 uses an infrared photoelectric sensor.
When visible smoke particles enter the sensing chamber, the optical signal changes. The internal circuit processes this signal and determines whether an alarm condition has been reached.
The product design includes features intended to improve operational stability, including:
The detector responds to visible smoke from both slow smoldering and open flaming fires.
The exact installation position should be selected according to the cabinet construction, smoke movement and equipment arrangement.
The detector should not be blocked by internal components, cables or structural parts. Smoke must be able to reach the smoke inlet.
The original installation requirements include:
For cabinet installations, the general placement requirements should be adapted by a qualified engineer to the actual enclosure dimensions and airflow conditions.
The standard Type B version uses the mounting-base terminals:
A Type A lead-wire version is also shown in the product documentation.
Before wiring:
Only qualified personnel should install or service the product because it is connected directly to an AC supply.
The AT-S234 is suitable when the customer requires:
It is especially useful when a 120VAC supply is already available but a conventional 24V fire alarm loop is not.
Another detector or complete fire alarm system should be considered when the project requires:
Selecting the correct product according to the actual system requirements helps prevent wiring errors and incorrect expectations.
The AT-S234 is available in two separate voltage versions:
The product is not a universal wide-voltage model.
For both versions:
Before ordering, confirm the following:
The detector should be inspected regularly for:
The original product instructions recommend performing a simulated fire alarm test every six months.
The test should confirm:
