Information on cabling - SmartRelay 3 system

Lines with data transmission

Cat 5 or installation cable for telecommunications systems (e.g. F-YAY 2x2x0.6)

Lines with data transmission and power supply

Cat 5 or installation cable for telecommunications systems (e.g. F-YAY 2x2x0.6)

Lines for power supply only

Any line (e.g. F-YAY 2x2x0.6)

IMPORTANT

Take voltage drop into account

The resistance in copper produces a voltage drop, the size of which depends on the cable gauge, current flow and cable length. The power supply lines must be adequately dimensioned.

  1. Ensure that the cable gauge in lines is adequate for power supply. Use another suitable cable where necessary.
  2. If required, merge wire pairs to increase the cable gauge.
  3. Use a power source located closer to the SmartOutput module if needed.
  4. If possible, increase the supply voltage (observe technical specifications).

IMPORTANT

Malfunctions due to interference

Sources of interference may impair functional reliability.

  1. Observe the installation instructions (see Installation).
  2. Use shielded twisted pair cables.
  3. Connect the cable shielding to the earth potential.

IMPORTANT

*) Undervoltage at the reader with PoE supply

When the controller is powered via PoE, a voltage converter reduces the PoE supply voltage to 13V. This voltage is available for supplying the connected readers and may not be sufficient for long cables or too small cross-sections to ensure trouble-free operation of the reader (see also Information on cabling). Take one of the following actions:

  1. Use an external power supply for the reader.
  2. Use an external power supply for the controller, whose voltage significantly exceeds 13 VDC to increase the internal supply voltage. This also increases the supply voltage for the reader and the voltage drop on the line no longer has any effect.
  3. Shorten the cable length.
  4. Increase the cable cross-section.

You can use the form to calculate sparkover for copper cabling. The form takes into account the maximum length which is calculated based on the voltage drop. It does not check any other sources of interference such as transfer resistances or electromagnetic interference fields, which limit the maximum cable length to 300 m. The following formula is used:

The result is the maximum length, which is calculated based on the voltage drop. This length comprises a forward and return path. You should use an own power supply unit to increase operational reliability if the cable is more than 75% of the maximum calculated length.

Enter the following values into this form:

Value

Explanation

Supply voltage VIN [V]

Voltage in the connected power supply unit. Read the value on the power supply unit or ask the electrician responsible. Use 13 V if you supply the controller via PoE.

Enter the number without the unit and use a decimal point if necessary (e.g. 13.5)

Cable gauge A [mm²]

Cross-section of the installed or projected cable. Read the value on the cable or ask the electrician responsible.

Enter the number without the unit and use a decimal point (e.g. 0.5).

The following table contains the maximum lengths for frequently used cable gauges and supply voltages.

0.1022 mm² (=AWG27)

0.14 mm²

0.2 mm²

0.6 mm²

PoE

39 m

53 m

76 m

230 m

9 V

4 m

5 m

8 m

25 m

12 V

30 m

41 m

59 m

179 m

24 V

135 m

185 m

265 m

300 m

32 V

205 m

281 m

300 m

300 m