Supply Voltage - Danfoss AK-PC 781A User Manual

12

Supply voltage

Supply voltage is only connected to the controller module. The
supply to the other modules is transmitted via the plug between
the modules.
The supply must be 24 V +/-20%. One power supply must be used
for each controller. The power supply must be a class II.
The 24 V must not be shared by other controllers or units. The
analog inputs and outputs are not galvanically separated from the
supply.
The + and – 24V input must not be earthed.
If using stepper motor valves, the supply for these must be pro-
vided from a separate power supply.
For CO 2 facilities, it will also be necessary to safeguard the voltage
to the controller and valves using UPS.
Example continued:
Controller module
+ 2 extension modules in 200 series 10 VA
+ 2 extension modules in 100 series
Power supply size (least)
40
8 VA
4 VA
------
22 VA
Capacity controller RS8HE202 © Danfoss 2017-07
Power supply size
The power consumption grows with the number of modules used:
Module Type
Controller
Extension module 200 series
Extension module 100 series
Total
Common pressure transmitter
If several controllers receive a signal from the same pressure trans-
mitter, the supply to the affected controllers must be wired so that
it is not possible to switch off one of the controllers without also
switching off the others. (If one controller is switched off, the sig-
nal will be pulled down, and all the other controllers will receive a
signal which is too low)
Number á Effect
1 x 8 = 8 VA
_ x 5 = __ VA
_ x 2 = __ VA
___ VA
AK-PC 781A