Large Bore Hollow Shaft Encoders with Magnetic Sensing

Hollow shaft mounting combined with magnetic sensing technology allows the NorthStar HT55 and HT85 encoders to be reliable and adaptable in AC motor applications.

Relentlessly reliable feedback starts with large bore magnetic encoders. The NorthStar HT55 and HT85 large bore hollow shaft encoders provide reliable signal output and downtime reduction with features such as magnetic sensing, broad temperature versatility, high shock and vibration resistance, and contaminant protection thanks to magnetic sensing. These encoders also boast large bore size options to allow easy, yet secure mounting for any application.


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HT55 Installation Manual »


HT85 Installation Manual »



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Mount to Large Motor Shafts with Ease

Dynapar encoder experts designed the NorthStar HT55 and HT85 hollow shaft magnetic encoders to mount to large motors quickly and easily on shafts up to 4.5 inches (115mm) in diameter. A hollow shaft allows users to easily mount the encoder with or without NEMA C-face provisions or through a fan shroud via a single point tether. Wiring the HT series is also a breeze with reverse polarity and short circuit protection helping to forgive common wiring mistakes such as crossing power and signal wires.

  • Bore sizes ranging from 1/2" (12mm) up to 4.5" (115mm) 
  • Single or dual output options for redundancy 
  • Rod or single point slotted tether options for easy mounting

Real-Time LED Indicators for Your Peace of Mind

Following installation, verify encoder status with real-time LED indicators that glow green if power is properly supplied to the encoder and blinks to confirm pulse output.

The visual indicator also flashes red when low power or potential line driver issues are present. LED indication is a standard feature of the HT85 and HT55 Series encoders and does not require additional wiring or power supply.

You can have peace of mind that Dynapar large bore magnetic encoders are installed correctly and ready to withstand the harshness of the environment.

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Reliable in Heavy Duty Environments

Magnetic sensing technology uses changes in magnetic fields to sense the rotation of the encoder pulse wheel and sends the response as a digital signal to the controlling device. This technology allows the encoder to detect position and speed information without the interference of contaminates such as dust, dirt and water, elements that affect accuracy and reliability in other types of encoders. Rotary encoders with magnetic sensing outperform optical encoders in demanding environments such as steel mills, pulp and paper mills, and sawmills.




Discover performance improvements with large bore magnetic encoders today!

Discover relentlessly reliable feedback and easy installation with the NorthStar HT55 and HT85 encoders. Please fill out the form to request a quote and a consultation to determine if the right solution for your feedback needs by our application engineers today.

What our experts are saying:

“Our large bore magnetic encoders outperform optical hollow shaft encoders in dirty and rugged environments. These units are easy to mount and with visual indication that you've done the job correctly, providing peace of mind in the field."

- Jamar Daniels, Product Manager

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