H. Kuhnke Ltd, Romsey, UK
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Encoder Installation Guidelines

Electrical

Ground the cable shield and all other parts of the system requiring grounding, from a single point, to ensure that the ground connections are all at the same electrical potential. Always adhere to the latest standards and manufacturers recommendations.

To give protection from electrical noise being induced into the encoder circuit, main ac power cables should always be routed well away from the encoder wiring. Run all encoder wires independently from all other wires.

For more protection against electrical noise, or where it is an electrically noisy environment, specify encoders with complementary output signals and connect with twisted pair shielded wire. Induced currents should self cancel. Signal distortion can be eliminated by putting the complementary signals through a differential receiver at the instrument end.

When using long cables (hundreds of feet) cable capacitance can cause signal distortion. To minimise the distortion use low capacitance cable and use encoders with differential line drivers or complementary outputs in conjunction with a differential line receiver. Follow the manufacturers/suppliers recommendations with regard to maximum cable length.

 

Mechanical

If handled correctly encoders should give years of satisfactory service, however, there are a number of things that can cause damage and void the warranty.

The following are some of the more common reasons for such premature failure and should be avoided:

Subjecting the encoder shaft to axial or radial stresses beyond the manufacturers stated load figures.

Hammering the end or side of the shaft.

Subjecting the encoder to mechanical shock or vibration beyond its specification.

Disassembling the encoder.

Using rigid couplings or makeshift mounting technique.

Drilling the encoder shaft or case.

Also please note the following:

Particularly if a belt, or chain and sprocket, are used to rotate the encoder shaft, ensure that axial and radial loadings are always within manufacturer's specification otherwise the encoder bearings may be damaged.

Where hollow shaft encoders are fitted, care needs to be taken when removing the encoder from the shaft. Ensure all fixing screws are removed and be aware that excessive removal force can damage the encoder and its bearings.