Datasheet
PSR-MS60
106171_en_01 PHOENIX CONTACT 10
13 Calculating the power dissipation
Input power dissipation
P
Input
=U
B
²
/(U
S
/I
S
)
Contact power dissipation
With the same load currents:
P
Contact
=nI
L
²
25mΩ
With different load currents:
P
Contact
=(I
L1
²
+I
L2
²
+...+I
Ln
²
)25mΩ
Total power dissipation
P
Total
=P
Input
+P
Contact
therefore
P
Total
=U
B
²
/(U
S
/I
S
)+nI
L
²
25mΩ
or
P
Total
=U
B
²
/(U
S
/I
S
)+(I
L1
²
+I
L2
²
+...+I
Ln
²
)25mΩ
Key:
The total power dissipation of the safety relay
is based on the input power dissipation and
the contact power dissipation for the same
and for different load currents.
Designation Explanation
P Power dissipation in mW
U
B
Applied operating voltage
U
S
Rated control supply voltage
I
S
Rated control supply current
n Number of enabling current paths used
I
L
Contact load current