Allen-Bradley 800T vs. 800H Pilot Devices: How to Choose the Right Push Button, Selector Switch & Pilot Light
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The core difference between Allen-Bradley 800T and 800H pilot devices comes down to mounting hole size and construction era — 800T uses a 30.5mm cutout and is the legacy heavy-duty line, while 800H uses a 30mm cutout and is the modern metal/plastic line with broader accessory options. This guide breaks down when to use each, how to read the part numbers, and what to check before mixing them in the same panel.
800T vs. 800H Comparison
| Feature | 800T | 800H |
|---|---|---|
| Mounting Hole | 30.5mm | 30mm (also 22mm variants available) |
| Housing Material | Metal (heavy-duty) | Metal or plastic options |
| Product Era | Legacy / long-running line | Modern, broader current catalog support |
| Typical Use Case | Retrofits, legacy panel matching, heavy industrial | New panel builds, general industrial and washdown |
| IP Rating Options | IP65 common | IP66/IP69K available on select models |
Decoding the Part Number
Allen-Bradley pilot device catalog numbers follow the pattern [Bulletin]-[Function]-[Configuration]. On 800T, the bulletin prefix identifies the mounting size and series, followed by a suffix for color, illumination (add "A" for illuminated), and contact configuration (N.O./N.C.). 800H follows a similar structure but with its own suffix codes — always cross-check the full catalog number against the current Allen-Bradley pilot device catalog, since legend plate and contact block codes are ordered separately from the operator body.
How to Choose: Common Scenarios
- Panel has 30.5mm cutouts: Stick with 800T to avoid re-drilling the panel — 800H's 30mm operator won't seat properly in a 30.5mm hole without an adapter.
- Need illuminated vs. non-illuminated: Both lines offer illuminated pilot lights and push buttons — confirm voltage (e.g., 24VAC/DC, 120VAC) matches your control circuit before ordering.
- Replacing a legacy 800T device: Order the exact 800T replacement rather than switching to 800H unless you're prepared to modify the panel cutout.
- Washdown or harsh environment application: Check IP rating — 800H's higher IP66/IP69K-rated options are typically a better fit for washdown areas than standard 800T.
Compatibility Caveats
800T and 800H operators, contact blocks, and legend plates are generally not interchangeable between the two lines due to different mounting geometries and bases. Mixing both families in the same panel is common (e.g., new 800H stations added to a panel with existing 800T devices) but each device needs its own correctly matched cutout — don't assume a universal adapter exists for every combination. Always verify contact block quantity and configuration (1 N.O., 1 N.C., etc.) against your wiring diagram before ordering.
FAQ
Q: Can I put an 800H push button in an existing 800T cutout?
A: Not directly — the mounting hole sizes differ (30mm vs. 30.5mm), so you'd need to modify the panel or use an adapter plate if available.
Q: Is 800H a direct upgrade replacement for 800T?
A: Functionally similar, but not a drop-in physical replacement — treat it as a separate product line when planning panel layout.
Q: Do contact blocks interchange between 800T and 800H?
A: No — each line uses its own contact block design; always order the matching block for your specific operator.
Q: Which line has better availability for legend plates and accessories?
A: 800H generally has broader current accessory support since it's the more actively produced line, though 800T parts remain available for legacy panel support.
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