Siemens SIPLUS HCS Operating Instructions Manual page 30

Application planning
4.4 Installation location
Electromagnetic compatibility (EMC) and overvoltage protection
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
Connecting the 24 V DC power supply (Page 47)Section).
Power losses of the Power Output Module (POM)
When planning and dimensioning the cabinet cooling system, the power losses of the Power
Output Module (POM) must be taken into account. The power losses of a POM can be
calculated as follows:
P
LossPOM
P
LossChannel (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
Restriction of the switching power
Due to the different physical properties of heat emitters, restrictions can be imposed on their
permissible switching capacity depending on the type of heat emitter.
Short-wave halogen or infrared emitters ("flash emitters") have a high starting current due to
their relatively low cold resistance. The starting current can be several times the rated
current, especially during the first half waves.
Overloading of the internal fuses of the POM can occur depending on the number of
switching operations as well as the duration of switching operations and pause times.
NOTICE
Restriction of the switching power
If flash emitters with an output of more than 4000 W at 400 V are used, switching
operations can result in extremely high currents and the triggering of the channel fuses.
We therefore recommend that you have these emitters gauged by Siemens AG.
Derating of fuses
Note that fuses are subject to derating at high ambient temperatures, i.e. the rated current
for a fuse is reduced.
30
= P + P
LossChannel1 LossChannel2
= I(x) • 0.07 Ω + I(x) • 0.8 V
2
LossChannel (x)
+ ... + P + 6 W
LossChannel9
reduces proportionately.
Operating Instructions, 11/2015, A5E35452705A/002
SIPLUS HCS4300