802T-H — Heavy-Duty Industrial Limit Switch, Oiltight Enclosure

The 802T-H is a heavy-duty limit switch from the 802T series, built with an oiltight cast metal enclosure for industrial machine environments where contamination, vibration, and physical impact are routine. It detects mechanical position — a moving part reaching a defined point — and converts that motion into an electrical signal through a snap-action contact block, used for end-of-travel detection, interlocking, and position confirmation on machine tools, conveyors, and material handling equipment.

Specifications

Parameter	Value
Part Number	802T-H
Series	802T Heavy-Duty Limit Switch
Enclosure	Oiltight cast metal
Contact Type	Snap-action (NO/NC, per contact block)
Actuator	Lever/roller or plunger (model dependent)
Rated Voltage	Up to 600V AC (per contact block rating)
Enclosure Rating	NEMA 4, 13 (oiltight)
Operating Temperature	−40°C to 70°C (model dependent)
Standards	UL 508, CSA, IEC 60947-5-1

Why a Heavy-Duty Cast Enclosure

Standard plastic-bodied limit switches work fine in clean, low-impact environments. The 802T-H's cast metal housing exists for the applications that destroy plastic switches: machine tool environments with coolant and metal chip exposure, foundry and heavy manufacturing floors with constant vibration, and locations where the switch itself might take an occasional physical impact from material handling equipment or a dropped tool. The oiltight rating means cutting fluids, lubricants, and coolant spray don't penetrate the switch body and degrade the internal contact mechanism over time — a failure mode that plagues lighter-duty switches in machine shop environments.

The snap-action contact mechanism inside provides a defined, repeatable switching point regardless of how fast or slow the actuator approaches — useful for position detection where the actuating speed varies across different operating conditions of the machine.

Actuator Selection and Mounting

Lever/roller actuators suit applications where a cam or moving part sweeps past the switch at an angle — common on conveyor and indexing applications.
Plunger actuators suit direct, perpendicular contact applications — a moving slide or fixture striking the switch head directly.
Mount the switch so the actuator engages within its rated travel and over-travel range — operating beyond the rated over-travel repeatedly causes premature mechanical wear and eventual failure of the internal mechanism.
Verify the conduit entry is properly sealed with appropriate fittings to maintain the oiltight rating — an improperly sealed conduit entry defeats the enclosure's environmental protection regardless of the switch body's own rating.

FAQ

Q: Can the 802T-H be used as a safety-rated interlock switch?

Standard 802T switches are general-purpose position switches, not certified safety interlocks. For safety-rated guard interlocking, a switch specifically certified to the relevant safety standard (such as the 440 series) should be used instead.

Q: Is the contact block replaceable without replacing the entire switch body?

Yes, in most 802T configurations the contact block is a separate, replaceable component from the switch head and actuator assembly, allowing contact replacement after wear without discarding the full unit.

Q: What actuating force is typically required to trip the switch?

Actuating force varies by specific actuator type and spring configuration — check the model's datasheet for the operating force and travel specifications, since this varies meaningfully between lever, roller, and plunger variants.

Q: Can this switch be mounted in any orientation?

Mounting orientation affects gravity's influence on the actuator return spring in some configurations. Verify the manufacturer's mounting orientation guidance for the specific actuator type to ensure reliable return-to-rest behavior.

802T-H New Factory Sealed 802TH Limit Switch