EUCHNER CES-AH-C03-AH-SM (Unicode) - Manual (Page 10)

Operating Instructions Safety Switch CES-AH-C03-AH-SM
10
Voltage drop on cable and switch
If a load is applied to the outputs, voltage drops will occur on the supply cables
and on the switch.
The voltage drops are to be taken into account during the calculation of the power
available in the load connected.
Parameter Value Unit
Maximum resistance of an output path 250 mW
Resistance for further connection cable (e.g. 7 x 1 mm², supply
and return wire)
25 mW/m
Other connection resistances are to be taken into account as necessary.
Calculation example
Ì 10 m cable from the switch to the supply / load
Ì Supply voltage on the 24 V connection
Ì Load on channel A: 1 A
Ì Load on channel B: 4 A
For channel A:
Ì Voltage drop on the switch
D U
1
= R x I = 250 mW x 1 A = 250 mV
Ì Voltage drop on the cable
D U
2
= R
l
x l x I = 25 mW/m x 10 m x 1 A = 250 mV
Ì Voltage at the load
U = U
B
- D U
1
- D U
2
= 24 V - 0.25 V - 0.25 V = 23.5 V
For channel B:
Ì Voltage drop on the switch
D U
1
= R x I = 250 mW x 4 A = 1 V
Ì Voltage drop on the cable
D U
2
= R
l
x l x I = 25 mW/m x 10 m x 4 A = 1 V
Ì Voltage at the load
U = U
B
- D U
1
- D U
2
= 24 V - 1 V - 1 V = 22 V