User Manual

C. Technical appendix
C−15
Festo P.BE−SPC200−EN en 0901d
Ascertain by formula
Proceed as follows:
1. Calculate the maximum current consumption of the inter
nal electronics, the connected modules and measuring
systems (I
1
) as well as the load supply for outputs, field
devices and proportional directional control valves (I
2
)
(see also chapter 3.5.1).
2. Ascertain the lowest voltage to be expected during oper
ation (V
Bmin
) on the power unit. Take the following into
account:
· the load dependency of the power unit
· the fluctuations in the primary mains voltage
· the operating temperature of the devices.
3. Enter the values in the relevant formula. The equivalent
circuit diagram as well as the example explain the correla
tions.