Avtron XPH8 SMARTSafe™ Encoder

Avtron XPH8 SMARTSafe™ Encoder

Explosion Proof Bearingless Encoder

  • No Barrier or Isolator Needed
  • No Intrinsic Safety Ground Required
  • Class I Div 1 Groups C, D Listed
  • AEx Zone 1 Certified
  •  Zone 1 & 2 Certified
  • Fits Shafts Up to 4.5" [115mm]
  • Fully Protected Against Shorts and Wiring Errors
  • Adapters available to fit GEB20, 22, 28, GE 752 Motors
  • Wide Sensor-Rotor Gap:  No Shimming
  • Up 100000 PPR
  • -50°C to +85°C Operation
  • 2 Year No-Hassle Warranty
Outline Drawing
XPH8 SMARTSafe™ encoders are the world's first explosion-proof encoders with removable electronics and no external barrier!  They are cULus, ATEX, AEx & IECEx certified and offer incredibly reliable no-bearing construction!  SMARTSafe XPH8 encoders can be used in ATEX/IECEx, cUL AEX, and UL gas hazardous environments.  Also available:  no-bearing modular sensors (XP5), as well as intrinsically safe models (XR5, XR12, XR56, XR125, XR485, XR685, XR850) and hollow shaft models M6C.

For applications requiring ATEX/IECEx Zone 1 or 2 or cULus Class I, Division 1 or 2, Groups C & D use the XPH8 directly in your application with no barrier or isolator required.

Unlike the competition, Avtron SMARTSafe encoder systems are protected against short circuits, power-to-output wiring, and output-to-ground faults.  They feature full diagnostics:  it's easy to determine that signal quality is good-just look for the green LED.  Worried about wiring short circuits and errors?  XPH8 will indicate any short circuit conditions with an orange LED and will survive this condition!

No encoder bearing failures, no more sealing problems. Mount XPH8 directly on your motor.  Top drives, draw works, coil tubing, paint lines...so many applications benefit from a more reliable no-bearing encoder.  Vibration, shock, liquids, dust and dirt won't harm SMARTSafe XPH8 encoders!  

Eliminate the biggest cause of hazardous duty encoder failure--eliminate the bearings with XPH8 hazardous duty encoders.
Operating Power: Volts: 5-24VDC in/out; Current: 400mA max @ 5V; 200mA max @ 12V; 100mA max @ 24V (plus cable load)
Output Format: A Quad B with marker (A,/A, B,/B, Z,/Z)
Frequency Range: 0 to 250 KHz
PPR: 8-100000
Speed: 6000 RPM Max. (contact factory for higher speeds)
Maximum Cable Length: 1000 ft (305m) (contact factory for longer distances)
Rotor Positioning: Up to +/-0.100" [+/-2.54mm] movement/misalignment
Sensor-Rotor Gap: 0.040", +0.015/-0.030" [1mm+0.38/-0.76]
Temperature: -50°C to 85°C 
     (rotor -50°C to 100°C continuous, +135°C intermittent)
Environmental: IP65 fully potted sensors 
Vibration: 5-2000Hz, 18G; 100G Shock
Weight: 10-14 lbs. [4.5-6.4kg]
     Class I Div 1, Groups C and D
     Class I Zone 1, Ex db ia IIB T4 Gb
     Class I Zone 1, AEx db ia IIB T4 Gb
     Ex db ia IIB T4 Gb (ATEX/IECEx)

 *See installation drawings for Warnings and Limitation
  • All-digital design, no trim pots or adjustments for longer life
  • Superior line drivers withstand short circuits and reverse voltage wiring errors
  • Fully potted electronics
  • SMARTSafe sensors find problems before they cause failure
  • Mix and match any PPRs with any rotor
  • Allows gland or conduit connections
  • Full protection against motor shaft currents
Industry General Food & Beverage Pulp & Paper Wood Products Wind Power Crane & Hoist Metals Mining Marine Oil & Gas

Light Mill Duty

AV20, AV25, AV4, AV6A, AV6M, Avtron Elevator Encoder, Cables and Connectors, Encoder Couplings, Encoder Programming Tool, HS25A, HS35A, HS4, HS6A, K661, Rush AV4 Program, SC65

Mill Duty

AV32, Cables and Connectors, Encoder Couplings, HS35M, HS35X, HS6M, K661, M185, M3, M3(small), RAHS35M

Heavy Mill Duty

AV115, AV125, AV44, AV45, AV56, AV56-Wind, AV56S, AV67, AV85, AV850, AVSK, Cables and Connectors, Carlen Replacement, HS44, HS45, K661, M4, M4(small), XP5, XR115, XR12, XR125, XR45, XR4F, XR5, XR56, XR67, XR85, XR850, XR97, XRB1, XRB2, XRB3

Severe Mill Duty

AV12, AV30, AV485, AV5, AV685, Cables and Connectors, Carlen Replacement, Encoder Couplings, HS40, K661, M484, M6, M6C, M7, XP5, XPH1, XPH8, XR12, XR485, XR5, XR685, XR97, XRB1, XRB2, XRB3,
XPH8 SMARTSafe™ encoders can directly replace many competitive models including: 

Baumer Hubner:

EEx HOG 161, HOG8, HOG9, HOG10, HOG11, HOG131, HOG161, HOG163, HOG165 encoders


HS35, H37, H38, H40, L25 explosion proof and intrinsically safe encoders
924-08062-001, 924-08062-002, 924-08062-003, 924-08063-001, 924-08063-002, 924-08064-001, 924-08064-002, 924-08172-001, 924-08172-002, 924-08173-001, 924-08173-002, 924-08174-001, 924-08174-002, EM-DR1-IS-5-RTB-24V/V, EM-DR1-IS-5-RTB-24V/4, EM-DR1-IS-5-RTB-24V/OC intrinsic safety barriers & systems

BEI Ideacod encoders:

Dynapar encoders:
X25 encoder

RSI 58X-,RVI 58X-, RVI84, 14-1436X, 14-14361, 14-14366


And many other hazardous area, intrinsically safe and explosion-proof ATEX, IECEx, UL, cUL, CSA rated encoders. 
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In This Section

  • A Quad B

    A Quad B refers to the set of output quadrature signals from an incremental quadrature encoder to indicate speed and direction, including complements: A, A NOT, B, B NOT (, , , ). Most Avtron encoders offer A Quad B output at no extra cost.  For more information on quadrature- Wikipedia: http://en.wikipedia.org/wiki/Quadrature_phase

  • ATEX

    ATEX is a directive used worldwide for equipment, including encoders, to be used around or in explosive atmospheres. ATEX certified equipment is NOT necessarily interchangeable with US-based UL Class/Division or Class/Zone rated equipment, nor IECEx rated equipment. ATEX is an alternative and different system. Review our full line of Avtron Explosion Protected, ATEX certified encoders, including M6, M6C and XR models.

  • Bearingless

    These encoders use the bearings of the motor or machine, eliminating a huge source of failure in encoders.  Also known as modular and sandwich encoders.

  • Cam Screw Rotor™

    A Cam Screw Rotor eliminates the problems associated with slipping rotors of other types; it uses two cam (eccentric) head screws. The screws are preloaded into the rotor; simply rotate them (approximately 90°-180°) to fully engage the shaft (4-6 ft-lbs) using a standard hex (Allen) wrench. Cam screw rotors are available on AV850, AV56, AV67, AV85, and AV115 THIN-LINE II™ encoders. Cam Screw Rotor Patent # 7,485,997. Cam Screw Rotor™ is a trademark of Avtron.

  • Encoder

    A device which indicates position and speed via a set of digital outputs. Incremental encoders output quadrature (A Quad B) signals, and may add a marker pulse once per revolution.  Absolute encoders typically indicate position via a digital message, a set of parallel outputs, or analog values.

  • Explosion Protected

    Also known as Flameproof, explosion protected equipment has additional protection/safety enhancements for use in explosive atmospheres. Explosion Protected devices maybe placed directly into hazardous areas within their nameplate rating. No additional equipment is required if installation instructions are followed properly. By comparison, Intrinsically Safe devices may require the use of additional, external protection/current limiting devices outside of the hazardous area. Avtron offers hollow shaft M6C Explosion Protected encoders.

  • Face or Flange Mount

    A machined surface (NEMA 56C, NEMA FC) on the non-drive end of the motor is used to mount bearingless or pancake encoders such as Avtron AV56 THIN-LINE II™ encoders. Solid shaft, coupled tachometers also flange mounted using flange adapters, also called flowerpots.

  • Flange Adapter

    A Flange Adapter provides the NEMA 56C motor mounting face and properly locates the encoder shaft. The encoder shaft and motor shaft are then connected using a flexible coupling. (Drawing "A") Often flange adapters can be eliminated by directly mounting a modular encoder such as an Avtron AV125, AV850, AV56, AV67, AV85, AV115 unit on the motor flange. (Drawing "B")

  • IECEx

    IECEx is a directive used worldwide for equipment, including encoders, to be used around or in explosive atmospheres. IECEx certified equipment is NOT necessarily interchangeable with US-based UL Class/Division rated equipment, or ATEX rated equipment. IECEx is an alternative and different system. Avtron offers a full famliy of Explosion Protected, IECEx certified XR encoders, and M6C is also IECEx certified.

  • Incremental Encoder

    An encoder that produces pulses in proportion to distance moved or rotated. Incremental encoders can also have a marker pulse Z, Z NOT (, ) once per revolution to provide a position reference. Avtron produces a full range of incremental rotary encoders.

  • Line Driver

    The chip or output circuit that forms the electrical pulses output from the encoder. Avtron has extremely advanced line driver technology to prevent damage from overvoltage and short circuits. Avtron offers optional high-power line drivers to permit Avtron encoder signals to travel farther down long wires to remote controller/drive locations without the need for repeaters or amplifiers.

  • Magnetic Encoder

    Magnetic and magnetoresistive encoders typically use a magnetized rotor with north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions, and these are the counts or pulses generated by the encoder. Magnetic encoders withstand dirt, dust, water, and temperature changes far better than optical encoders.

  • Magnetic Rotor

    A magnetized disk with multiple north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions and generates the pulses generated by the magnetic encoder.

  • Magnetoresistive Sensor

    A sensor that detects the magnetic poles on an encoder's magnetic rotor and transforms them into pulses. Avtron magnetoresistive (MR) sensors use advanced technology to reject external magnetic signals such as brake solenoids and motor magnetic fields. MR sensors enable Avtron magnetic encoders to ignore dirt, oil, water, and other contaminants.

  • Marker Pulse

    The Marker Pulse occurs once per revolution. The purpose of the marker pulse is to provide a repeatable home position location for positioning applications. The marker pulse is often abbreviated as "ØZ" or "Z" in the USA and "C" or "N" in Europe.

  • Modular Encoders

    Modular Encoders mount to a machined C-face or flange adapter on the motor (drive or non-drive end). Modular encoders consist of a rotor that mounts on the shaft, and a stator that bolts to the motor frame. Modular encoders are very rugged, and Avtron encoders feature Wide-Gap sensors to avoid complex shimming or fitting to the motor. Modular C-face encoders are typically used on DC motors; but some AC motors, such as Rockwell’s RPM III AC and Marathon’s Blue and Black Max motors, have C-faces standard on the non-drive end for mounting an encoder.

  • Motor Shaft Currents

    The high-speed switching of variable frequency drives that is used to control the speed of motors often produces current which flows from the motor shaft to ground, or from end-to-end of the motor.  These current are highly destructive to both motor and encoder bearings.  Preventing shaft current damage is essential.  Most Avtron hollow shaft encoders include features to prevent motor shaft current damage.  For more information:  http://www.avtronencoders.com/knowledge-base/eliminating-damage-from-motor-shaft-currents-through-tachometers-and-encoders or visit Wikipedia:  http://en.wikipedia.org/wiki/Shaft_voltage

  • MR

    Magnetoresistive (MR) sensors are used in Avtron encoders to provide high accuracy and superior reliability versus optical sensing systems.  For more information on magnetoresistivity:  Wiki:  http://en.wikipedia.org/wiki/Magnetoresistive

  • Optical Encoder

    An Optical Encoder typically uses a light source shining through, or reflecting off, an optical disk with lines or slots that interrupt the beam of light to an optical sensor. Electronics count the interruptions of the beam and generate the encoder’s output pulses.

  • Optical Errors

    Optical Errors include false pulses, missed pulses, and quadrature errors that are generated when there is any type of contamination (dirt, oil, water, condensation) on the optical disk.

  • Pulses

    Pulses are also known as counts and are the low voltage output transitions which indicate movement of the encoder. Encoders are rated by resolution or PPR (pulses per revolution). Pulses are not the same as lines.

  • Quadrature

    To determine which direction an encoder is revolving, encoders output quadrature signals: two streams of pulses, A & B, generated at 90° timing angles. (Also called A Quad B) A leading B indicates rotation in one direction; B leading A indicates the encoder is rotating in the opposite direction. Example: “A leads B with clockwise rotation as viewed from the encoder face on an HS45 encoder." Many encoders with quadrature outputs also have complementary outputs: A NOT and B NOT signals.

  • Quadrature Errors

    Failures of the encoder to generate properly formatted quadrature signals. Most typically, these are failures to create the proper 90° signal separation between the A and B channel outputs, with a less than perfect stream of square waves. Most controllers, when presented with a quadrature error, will report a drive fault or encoder fault and then shut down.

  • Resolution

    Resolution describes how many individual slices or positions can be reported by an incremental or absolute encoder.  For incremental encoders the number of PPR (pulses per revolution) expresses resolution; for absolute encoders, PPR, or counts per turn or bits of resolution may be listed.

  • Rotary Encoder

    A rotary encoder provides position and/or speed feedback information about a rotating shaft.  Rotary encoders may be hollow shaft, no-bearing modular, coupled solid shaft style.  They may provide absolute positioning information, or incremental velocity feedback. Avtron rotary encoders are designed and built to be far more reliable than ordinary rotary encoders. Avtron encoder white papers on our blog provide more details of how and why Avtron rotary encoders are more reliable.

  • Shimming

    Often, to produce precise stub shaft, modular encoder, or foot mount installation, shims are placed between the two items to be aligned. Avtron encoders are designed to eliminate the need for shimming. Many competitors’ modular encoders still require shimming for proper operation.

  • Shims

    Thin pieces of metal used to precisely space two parts. They are used for shimming a stub shaft, encoder rotor, or foot mount installation.

  • Solid Shaft

    Solid Shaft encoders are coupled to the shaft to be measured. The solid shaft encoder body is typically C-Face mounted using a flange adapter, or some models can be foot mounted.

  • UL Listed

    UL Listed Avtron encoders can be directly applied to any hazardous duty application which requires Class and Division, Class and Zone or AEX certification.  Note that UL Listing is a different system than ATEX or IECEx.  Ensure the model you select has the UL listing which meets the application requirements.

  • Wide-Gap Technology

    Avtron encoders use special optical sensors and magnetoresistive sensors, combined with proprietary circuit designs to allow the sensor to be located much farther from the magnetic rotor or optical disk. This eliminates sensor crashes and makes mounting easy and forgiving of mechanical variation.

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