Cleveland Controls AFS-952-B Switch

The Cleveland Controls AFS-952-B is a field-adjustable differential air pressure switch designed for critical monitoring in commercial HVAC and industrial combustion systems. Engineered with a large silicone diaphragm, this switch accurately detects positive, negative, or differential pressure within a broad set point range of 0.03" w.c. to 12.0" w.c.. As a veteran-grade air flow proving switch, it features an integrated 8-second time delay relay to suppress nuisance shutdowns caused by momentary draft fluctuations or air turbulence during startup. This SPDT pressure switch is rated for 120V to 277VAC and can handle a maximum pressure of 0.5 PSI. The rugged NEMA-1 enclosure and 1/4" NPT sample line connectors ensure a secure fit for furnace draft control, filter monitoring, and combustion air safety applications. Whether you are managing light industrial blowers or complex energy management systems, the AFS-952-B provides the reliable switching precision required for high-stakes HVAC pressure sensing.

• Universal Compatibility: Monitors positive, negative, or differential pressures in diverse industrial air handling environments.
• Anti-Nuisance Logic: Built-in 8-second time delay prevents unnecessary system restarts due to normal environmental pressure spikes.
• Flexible Adjustment: Field-adjustable screw allows for fine-tuning the operating set point from 0.03" up to 12.0" w.c.
• Rugged Durability: Rated for over 100,000 cycles at maximum electrical load, ensuring longevity in high-demand mechanical rooms.
• Versatile Media: Suitable for use with air and non-combustible gases that stay within the compatible limits of the silicone diaphragm.

How do I adjust the set point on the AFS-952-B?
Remove the plug button on the cover and use the internal adjustment screw. Turning clockwise increases the set point while counter-clockwise decreases it. It is elite practice to verify your settings using a digital manometer during commissioning.

What is the purpose of the 8-second time delay?
The delay ensures the internal relay only trips if a pressure drop or rise is sustained. This prevents high-efficiency burners or fans from shutting down during brief periods of turbulence or wind gusts at the intake.

Can this switch be used to monitor air filter status?
Yes. By connecting the high-pressure port upstream and the low-pressure port downstream of the filter, the switch will trigger once the differential pressure exceeds your set point, indicating a restricted or dirty filter.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.