Danfoss AK-PC 551 Design guide

AK-PC 551 Refrigeration Controller

Technical brochure

2 Technical brochure RC8CF102 © Danfoss 08-2014 AK-PC 551

Content

Introduction �� 4

Applications 4 Compressor combinations 5 Condenser combinations 5 Inputs and outputs 5

Basic Operation �� 6

Status 6 Password 6 Logout 6 Setup & service 6 View parameters 8 Change parameters 8 Day / night schedule 8

First time start up �� 9

Conguration 9

Example: Application �� 10

Application: Digital scroll 10

Example: Wiring Diagram �� 11

Electrical wiring 11 Connection, lower level 11 Electrical diagram 11 Connection, upper level 11

Example: Wizard �� 12

Wizard setup 12

Example: Check IO conguration �� 14

Wizard assignment of inputs and outputs (I/0) 14 Assignment of inputs and outputs 14 IO conguration error 15

Example: Add extra I/O �� 16

Example: Check I/O wiring �� 17

Initialize the controllers IO conguration 17

Network setup �� 18

Example: Quick conguration �� 19

Quick conguration 19 Application table 20

Frequently asked questions (FAQ) �� 22

AK-PC 551 Technical brochure RC8CF102 © Danfoss 08-2014 3

Introduction

This technical brochure will give you a short introduction to the AK-PC 551 pack controller� With an application example, it is shown how easy the controller is congured and operated through the graphical display�

The AK-PC 551 is a pack controller for 1 or 2 suction groups of compressors and a common condenser�

AK-PC 551 supports a variety of compressor combinations including variable speed, Digital scroll and Stream 4 cylinder compressors� Additionally it oers a large number of energy saving functions and optimization features�

AK-PC 551 can be fully congured through a LCD display� The LCD display can be built in and/or be a remote connected display�

AK-PC 551 has a compact size of 8 DIN modules� All inputs and outputs can be congured for a variety of functions making the controller highly adaptable to any pack application�

AK-PC 551 can be connected into a MODBUS communication network and is available with 24 Vac or 110-230 Vac power supply�

Applications

AK-PC 551 is used for capacity control of compressors and condenser fans on small to medium sized refrigeration systems� It covers the following main applications:

• One compressor group (max� 8 relays) and one condenser group

• Two compressor groups (max� 4 relays per group) and a common condenser

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Introduction

Compressor combinations

The compressor capacity can be controlled according to the suction pressure Po or a media temperature sensor S4� AK-PC 551 covers a variety of compressor combinations�

Condenser combinations

The condenser capacity can be controlled according to the condensing pressure Pc or a media temperature sensor S7 The condenser can be controlled in two ways:

• Speed control of all fans

• Step control of single fans

Inputs and outputs

All in- and outputs of an AK-PC 551 controller can be congured for various functions and signal types:

• 8 analogue inputs for pressure transmitters and temperature sensors�

• 6 digital relay outputs for compressors, fans, alarm�

• 2 digital solid state outputs for PWM control of Digital scroll or Stream compressor� If not used for this purpose they can be used as normal relay outputs�

• 2 analogue outputs for speed control of compressors and condenser fans�

Speed control of all fans Step control of all fans

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Basic Operation

Conguration and daily operation of AK-PC 551 is done via the built-in display or via a remote connected display� The display supports multiple languages and engineering units�

For a full description of the controller parameters please see the manual RS8GY

Status

Get an overview of how the system is running in the status screens� Use the LEFT / RIGHT buttons to view the status screens�

Suction statusHome Condenser status Active alarms Cleared alarms Controller information

Password

Parameters and menus are protected by a password that gives access on 3 dierent user levels�

Level 0: See parameters (000) Level 1: Change weekly schedule (100) Level 2: Change control setpoints (200) Level 3: Change conguration setpoints (300)

The password cannot be reset, so please remember the (level 3) password�

Logout

Go to the "Home" screen and hold down the X key for 5 seconds to logout�

Setup & service

In the main menu you will nd all control parameters divided into sub menus�

From any status screen press ENTER for 2 sec� to access main menu

Press ESCAPE to go back to status Press UP to decrease digit Press DOWN to increase digit

Press LEFT / RIGHT to go to next / previous digit

Press ENTER to login

Press ESCAPE to go one level back

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Basic Operation

The number of status screens and the presented data depends upon the congured application�

Home

Number of compressors running

(1 of 2 compressors is running)

Suction control sensor readout

Suction reference

Condenser reference

Condenser control sensor readout

Number of fans running

(1 of 2 fans is running)

Suction status

Running compressor capacity

Condenser control sensor

Condenser status

Condenser control sensor

Condenser reference Suction control sensor

Suction reference

Active alarms

Active alarm

Press ENTER to see alarm details

Alarm text Alarm priority Alarm activated at

To clear an alarm press ESC (X) for 2 sec�

Running fan capacity

Condenser reference

Cleared alarms

? temperature

Cleared alarm

Press ENTER to see cleared alarm details

Alarm text

Alarm priority

Alarm activated at

Alarm cleared at

Controller information

Technical controller information like code number and software version etc�

Basic Operation

View parameters

The display will only present parameters that are valid for the congured application e�g� if 4 compressors are selected only 4 are showed�

A partly highlighted row indicates that a parameter can be viewed and not changed�

Press ENTER

Control status menu

Change parameters

A full highlighted row indicates that a parameter can be changed� A changable parameter has a frame around the setting�

to select control status

Control status readout

Press ESCAPE to go back one level

Press DOWN to see next parameter

Control settings menu

Day / night schedule

System menu

to select setpoint

Press ENTER to select weekly schedule

Setpoint readout

Setpoint selected

Weekly schedule

Monday open time

Press ESCAPE to go one level back

Press DOWN to see next parameter Press ENTER to edit a parameterPress ENTER

Press ESCAPE to go one level back Press UP to increace the setpoint Press DOWN to decrease the setpoint Press ENTER to save the setpoint

Press ENTER to select day

Press ESCAPE to go one level back Press UP to increace the time Press DOWN to decrease the time

Press LEFT / RIGHT to go to hour / minute

Press ENTER to save the setting