19
2522722-01-05/19 (Translation of the original operating instructions)
Operating Instructions
Safety Relay with IO-Link ESM-CB
EN
11. Calculating the power dissipation
Important!
The total power dissipation of the safety relay results from the input power dissipation and the contact
power dissipation with equal or differing load currents.
Input power dissipation
P
input
= U
B
² / (U
S
/I
S
)
P
IO-Link
= U
BIOL
² / (U
IOL
/I
IOL
)
Contact power dissipation
With equal load currents:
P
contact
= n * I
L
² * 50 mΩ
With differing load currents:
P
contact
= (I
L1
² + I
L2
²) * 50 mΩ
Total power dissipation
P
total
= P
input
+ P
IO-Link
+ P
contact
therefore
P
total
= U
B
² / (U
S
/I
S
) + U
BIOL
² / (U
IOL
/I
IOL
) + n I
L
² * 50 mΩ
or
P
total
= U
B
² / (U
S
/I
S
) + U
BIOL
² / (U
IOL
/I
IOL
) + (I
L1
² + I
L2
²) * 50 mΩ
Key:
P
Power dissipation in mW
U
B
Connected operating voltage at A1 and A2
U
S
Rated control circuit supply voltage
I
S
Rated control supply current
U
BIOL
Connected IO-Link periphery supply voltage
U
IOL
IO-Link rated periphery supply voltage
I
IOL
IO-Link port supply current consumption
n
Number of safety contacts used
I
L
Contact load current
