Eltra EH 50 FA/FP Hollow Shaft Encoder

Name: Eltra EH 50 FA/FP Hollow Shaft Encoder | Seven Star LLC
Brand: Eltra
SKU: EH 50

A 50 mm through hollow shaft encoder rated from -40 to +100 degrees C

The EH 50 is a 50 mm diameter encoder recommended in the datasheet for motor feedback, and its small dimensions suit small-size motors. What separates it from most encoders of its size is the temperature range: operating and storage temperature are both printed as -40 to +100°C, combined with an IP 65 enclosure rating.

It uses a highly integrated optical ASIC and a wide 4.5 to 30 V DC supply. The through hollow shaft takes 8 or 10 mm shafts, and the mounting is chosen by model: the EH 50FA uses a coupling flange for front mounting and the EH 50FP uses a stator coupling for rear mounting. Three M3 x 35 screws are included. Output is a push-pull or line driver signal on a radial cable.

What the datasheet lists as main features

50 mm encoder recommended for motor feedback
Three channel output (A / B / Z) up to 1024 ppr
Highly integrated optical ASIC
Supply 5 to 30 V DC
Through hollow shaft up to 10 mm
Front mounting by coupling flange (FA) or rear mounting by stator coupling (FP)
IP 65 and -40 to +100°C

Technical specifications

Parameter	Specification
Models	50FA front fixing; 50FP rear fixing
Resolution	100 to 1024 ppr (100, 200, 256, 360, 400, 500, 1000, 1024)
Supply voltage	4.5 to 30 V DC with reverse polarity protection
Power draw without load	0.8 W max
Max load current	20 mA per channel
Output circuits	Push-pull HTL; line driver RS-422
Max output frequency	105 kHz
Index signal	90°e, gated A and B
Bore diameter	8 or 10 mm, through
Enclosure rating	IP 65 (IEC 60529)
Max rotation speed	6000 rpm
Shock / vibration	50 G, 11 ms / 10 G, 10 to 2000 Hz
Moment of inertia	0.5 x 10-6 kgm2
Starting torque	Below 0.01 Nm at +20°C
Materials	Shaft stainless steel; housing aluminum
Bearings	2 ball bearings, life 109 revolutions
Cable	Shielded, fixed installation, 0.22 mm2, min bend radius 60 mm
Operating and storage temperature	-40 to +100°C; no condensation
Weight	150 g (FP); 200 g (FA)
MTTFd / mission time	54 years / 20 years per EN ISO 13849-1; DC 0 %
Approvals printed	UL / CSA file E212495; EMC 2014/30/EU; RoHS 2011/65/EU

Ordering code and model choice

The datasheet example is EH 50FP 1024 S 5/30 P 6 X 6 PR . XXX. Note that 6 in the bore position of the example is not among the 8 and 10 mm bores listed in the specification table, so confirm the bore with the manufacturer.

Code position	Options
Model	50FA through hollow shaft, front fixing; 50FP through hollow shaft, rear fixing
Resolution	100 to 1024 ppr
Zero pulse	S without, Z with
Power supply	5/30 for 5 to 30 V DC
Electrical interface	P push-pull; L line driver; RS 5/30 V DC supply with RS-422 output
Bore	8 or 10 mm
Enclosure / speed	X = IP 65 / 6 = 6000 rpm
Output type	PR radial cable, 0.5 m standard; 1.5, 2, 3, 5 or 10 m optional
Variant	XXX custom version

Installation and operating notes

Use a g6 mating-shaft tolerance. The FA variant bolts to a coupling flange at the front of the motor, while the FP variant is a rear-mounted stator-coupled design; choose the one that matches the free end of the motor.

Wiring is red +V DC, black 0 V, green A+, yellow B+, blue Z+ and, for line driver, brown or grey A-, orange B- and white Z-. The cable is rated for fixed installation only, so do not route it to a moving part.

At the 105 kHz output limit and 1024 ppr the maximum speed from the pulse rate is about 6150 rpm (derived: 105000 x 60 / 1024), which agrees with the 6000 rpm mechanical limit.

Applications for the EH 50

Small servo and asynchronous motors, spindle motors, fan and pump drives and compact gearmotors are the natural fit. The -40 to +100°C range makes the encoder a candidate for motors that run hot or are exposed to rapid temperature changes.

For outdoor motors in the Gulf, the IP 65 rating covers dust and water jets but the enclosure is not described for salt-laden coastal air or for hazardous areas; for classified zones see the Eltra EX 80. This is general selection advice.

Information to send with an RFQ for the Eltra EH 50

Send the information below to receive a quotation for the EH 50.

FA front mounting or FP rear mounting
Motor shaft diameter, 8 or 10 mm
Resolution and zero pulse requirement
Supply voltage, output type and cable length

Commissioning and maintenance notes

The wide temperature range of the EH 50 is useful in the region, where motors on pumps, fans and conveyors may run in hot plant rooms or outdoor enclosures, and where heat from the motor adds to the ambient temperature. Before installation, check that the bore matches the motor shaft and that the anti-rotation arm or spring is fixed so it does not load the bearings. Avoid hammering the encoder onto the shaft, as shocks can damage the optical disc and bearings.

Match the output type and supply voltage with the drive or counter input, and use shielded cable with the shield earthed as described in the manual, keeping the encoder cable away from motor power cables. Inspect the connector, cable and fixing during routine maintenance, and replace damaged cables at once.

When ordering a replacement, record the resolution, output type, bore and connection of the existing encoder, so the new unit matches without changes to the drive settings. Keeping one spare encoder for critical motors shortens downtime.

Frequently asked questions

What temperature range does the EH 50 cover?

-40 to +100°C for both operation and storage, without condensation.

What is the difference between FA and FP?

FA is front fixing through a coupling flange; FP is rear fixing with a stator coupling.

What bore diameters can be ordered?

8 mm or 10 mm through hollow shaft.

What enclosure rating does it have?

IP 65 according to IEC 60529.

What output circuits are available?

Push-pull HTL and line driver RS-422.

Encoders for motors, lifts and machinery

Eltra describes application areas such as industrial automation, motor feedback, lift systems, packaging, light material processing, heavy duty industry, off-highway vehicles and potentially explosive atmospheres. Hollow shaft and solid shaft designs, bore sizes from a few millimetres to 40 mm, resolutions up to 24000 ppr and enclosure ratings up to IP 67 are printed in the Eltra datasheets.

Frequently Asked Questions