Allen-Bradley 836-C7A Pressure Control Switch, 4 to 150 PSI, NEMA 1

Allen-Bradley Bulletin 836 Type C industrial pressure control switch, adjustable over a 4 to 150 PSI operating range with an adjustable differential, in a NEMA Type 1 enclosure. This is the heavy industrial alternative to a commodity compressor pressure switch, built by Rockwell Automation in the United States.

Most packaged air compressors leave the factory with a light-duty pressure switch that is sized to the price of the machine rather than to the duty it will see. On a compressor that runs hard, on a plant air system feeding production, or anywhere a nuisance failure means downtime that costs real money, the Bulletin 836 is the part people step up to. It uses an external bellows actuator rather than a diaphragm, carries a 300 PSI maximum line pressure rating against a 150 PSI top setting, and is rebuildable and field-adjustable in a way that a sealed commodity switch is not.

Key specifications

• Operating range: 4 to 150 PSI, adjustable
• Differential: adjustable, 2.5 to 25 PSI
• Maximum line pressure: 300 PSI, with occasional surge to 375 PSI
• Actuator: external bellows, copper alloy
• Enclosure: NEMA Type 1
• Poles: 2
• Maximum voltage: 600 VAC
• Terminal connection: cable screw gland
• Manufactured in the USA; Build America, Buy America compliant

Where it is used

Air compressor start and stop control on reciprocating and rotary units, pump control on booster and transfer sets, pressure-limit and interlock duty on hydraulic and process lines, and any application where a wide adjustable differential is needed to stop a motor short cycling. The adjustable differential is the feature worth paying for on a compressor: widening the gap between cut-in and cut-out is the single most effective way to cut the number of motor starts per hour, which is what kills contactors, start capacitors and motor windings.

Setting it up

Set the cut-out pressure first, then set the differential to give the cut-in you want, and recheck the cut-out afterwards because on most bellows switches the two adjustments interact. Aim for the widest differential your air system will tolerate rather than the narrowest, and confirm the compressor unloads properly at shutdown so the motor is never asked to restart against head pressure.

Confirm before you order

Bulletin 836 is a large family and the suffix matters. This listing covers the 836-C7A specifically. The port connection size and the exact contact arrangement are not published consistently across distributor data for this catalog number, so if you are replacing an existing switch and either of those is critical, send us the nameplate off the old unit or the catalog number from your panel drawing and we will confirm the match before shipping.

Allen-Bradley 836-C7A pressure control switch, Bulletin 836 Type C, 4 to 150 PSI adjustable with 2.5 to 25 PSI adjustable differential and NEMA Type 1 enclosure, supplied by AirComParts through the Warthog Air Compressor Store alongside compressor pressure switches, unloader valves, starter coils and motor overload relays.