AK-CC 750A
RS8HP102 © Danfoss 2018-09
39
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 transformer
must be used for each controller. The transformer 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. See AK-XM 208C.
It will also be necessary to safeguard the voltage to the controller
and valves using UPS.
Transformer size
The power consumption grows with the number of modules used:
Module
Type
Number á
Effect
Controller
1 x 8 =
8 VA
Extension module
200-series
_ x 5 =
__ VA
Extension module
100-series
_ x 2 =
__ VA
Total
___
VA
12
Example continued:
Controller module
8 VA
+ 1 extension module in 100-series
2 VA
------
Transformer size (least)
10 VA
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)