Operation; Data Communication - Danfoss AK-PC 351 User Manual

Introduction
Application
The controller is used for capacity regulation of compressors
and condensers in small refrigeration applications. A maximum of
4 compressors and one condenser can be regulated. For example:
• One suction group + one condenser group, max. 6 steps total
• One compressor group, max. 4 steps
• One condenser group, max. 4 steps
Advantages
• Energy savings via:
- Optimisation of suction pressure
- Night set back
- Floating condensing pressure
Input and output
There are a limited number of available inputs and outputs.
For each signal type, though, the following can be connected:
• Analogue inputs, max. 4 pcs.
Signal from 2 pressure transmitters and 2 temperature sensors
• Digital inputs, max. 8 pcs.
Signal from automatic safety control, external start stop, night
signal, general alarm.
• Relay outputs, max. 5 pcs.
Connection of compressors, condenser fans, alarm relay
• Solid state outputs, max. 1 pcs.
Control of bypass on a digital scroll or for controlling unloader
on a stream compressor. If the output is not used for this func-
tion, it can be used as ordinary relay output
• Analogue outputs, max. 2 pcs.
Speed control of compressors and condenser fans.

Operation

The daily operation can be set up directly on the controller.
During set-up, the display images will be adjusted so that only
the relevant images are opened for additional setting and
end-user operation.
The operation is password protected, and three levels of
access can be granted.
The controller contains several languages. Select the preferred
language at start-up.

Data communication

The controller has built-in Modbus data communication, and it
can be connected to an AK-SM 800 type system device.
2 User Guide RS8GZ302 © Danfoss 2015-06 AK-PC 351