Specifications
RK0YG302 © Danfoss 04/2007 97
On/O control
Modulating control
EKC 414A1
Liquid supply
The supply of liquid is controlled on the basis of signals from the
pressure transmitter, temperature sensor S2 and the air tempera-
ture. The sensors create a signal so that the superheat is continu-
ously kept at a minimum whatever the operating conditions.
The AKV valve functions both as expansion valve and solenoid
valve. The valve opens and closes based on signals from the
controller.
Temperature control
The temperature is controlled on the basis of signals from one
or two temperature sensors. If there is only one sensor it may
optionally be placed in the air before or after the evaporator. If
there are two sensors, one must be placed before and one after
the evaporator. With a setting it is subsequently dened how
large an inuence the individual sensor is to have on the control.
The actual temperature control can take place in two ways: as
an ordinary ON/OFF regulation with a belonging dierential, or
as a modulating control there the temperature variation will not
be nearly as great as in ON/OFF control. There is however a limit
to the use of them as a modulating control can only be used in
central plant. In a decentralised plant the thermostat function
with ON/OFF control should be selected.
In a central plant the thermostat function may either be selected
for ON/OFF control or modulating control.
Defrost
With a simple function defrost can be started x times per day and
night. But the controller may also receive a signal from a defrost
clock or from another unit via the data communication, so that
defrost will take place at dened times of the day or night.
An on-going defrost can be stopped based on temperature,
normally the one measured with the S5 sensor, or it may be
stopped based on time. A combination with stop based on
temperature and with the time factor as a precautionary measure
is also a possibility.
Clock module (accessory)
If the controller is mounted without data communication and
defrost has to be carried out at specic times, a clock module can
be mounted.
The controller comes prepared with plug and terminals so that the
module just has to be pushed in.
Subsequently, up to six defrosts per day can be set. The module
has battery back-up.