Specifications

8 RK0YG302 © Danfoss 05/2007
Capacity regulation
The cut-in capacity is controlled by signals from the connected
pressure transmitter (temperature sensor) and the set reference.
Outside the reference a neutral zone is set where the capacity will
neither be cut in nor out.
Outside the neutral zone (in the hatched areas named +zone and
-zone) the capacity will be cut in or out if the regulation registers
a change of pressure (the temperature) “away” from the neutral
zone. Cutin and cutout will take place with the set time delays.
If the pressure (the temperature) however “approaches” the
neutral zone, the controller will make no changes of the cut-in
capacity.
If regulation takes place outside the hatched area (named ++zone
and --zone), changes of the cut-in capacity will occur somewhat
faster than if it were in the hatched area.
Cutin of steps can be dened for either sequential or cyclic opera-
tion.
Capacity control
Application
The controller is used for capacity regulation of compressors or
condensers in small refrigerating systems.
Regulation can be carried out with up to four identical capacity
steps.
Advantages
• Patented neutral zone regulation
• Sequential or cyclic operation
Functions
• Regulation
Regulation with up to four relay outputs can be carried out.
Regulation takes place with a set reference which is compared to
a signal from a pressure transmitter or a temperature sensor.
• Relay module
It is possible to use the controller as relay module, so that the
relays are cut in or out by means of an external voltage signal.
• Alarmfunction
A relay becomes activated when the set alarm limits are ex-
ceeded.
• Digital input
The digital input can be used for:
- night operation where the suction pressure is raised
- heat recovery where the condensing pressure is raised
- external start/stop of the regulation.
- Monitoring of safety circuit
• Possibility of data communication
Display
A signal from a pressure transmitter will always be converted and
shown as a temperature value.
Settings are made as for temperature values.
EKC 331T
EKC 331T