Siemens SIPLUS HCS Series Operating Instructions Manual page 34

Application planning
4.4 Installation location
Overvoltage protection 24 V DC power supply
NOTICE
Damage to the device
Inadequately dimensioned overvoltage protection can result in severe damage to the
device.
Always ensure, therefore, that the overvoltage protection is adequate (see section
Connect 24 V DC power supply (Page 55)).
Power loss of the POM4320
When planning and designing the cabinet cooling, take into consideration the power loss of
the POMs. The power loss of a POM is calculated as follows:
P
LossPOM
P
vChannel (x)
x represents the channel number
This power loss occurs at 100% activation of the channels. If the channels are not 100%
activated, the power loss P
Power loss of the POM4320 Highend
The calculation formula specified for the POM4320 also applies to the POM4320 Highend
with internal incoming fuse.
If the incoming fuse is missing (e.g. with star connection or the fuse is implemented
externally), the following formula applies:
P
vChannel (x)
32
= P + P
LossChannel1 LossChannel2
= I(x) • 0.04 Ω + I(x) • 0.8 V
2
LossChannel (x)
= I(x) • 0.033 Ω + I(x) • 0.8 V
2
+ ... + P + 6 W
LossChannel9
reduces proportionately.
SIPLUS HCS4300 PROFINET/PROFIBUS DP
Operating Instructions, 10/2019, A5E35452705A/005