Danfoss AKC 55 System Installation guide

Brand: Danfoss

Model: AKC 55 System

Type: Installation guide

AKCESS System Manual RC.IU.B1.22 4/99.1 1-1

Chapter 1 Introduction

In the design and production of a new generation of control and monitoring systems for supermar-

kets, Danfoss listened to a wide variety of users, including equipment manufacturers, installers,

facility managers, and service personnel. The result of extensive user involvement during continuing

development, the Danfoss AKCESS system makes tomorrow’s supermarket control a present-day

fact, and makes it easy, too.

The fundamental building block of the AKCESS system is the Danfoss AKC 55 Controller. It is

easy-to-configure and easy-to-use, and has features to answer every user’s needs.

The AKC 55 has a keypad and a graphic display, and features icon-driven software. The AKC 55

is completely user-configurable, with no need for a separate “database” file of equipment and

control parameters.

The illustration above shows the basic AKCESS AKC 55 System components, except for sensors. We’ll

first discuss system capacities, then introduce each component in detail.

1 - 2 System Manual RC.IU.B1.22 4/99.1 AKCESS

System Capacities

An AKCESS system can have up to 15 AKC 55’s making up a Host Network. Each AKC 55 can have

up to 95 I/O network nodes. Nodes can be:

RO8 Relay Output boards (8 relay outputs each)

VO2 Variable Output boards (2 variable outputs each)

OI8 On/Off Input boards (8 on/off inputs each)

SI8 Sensor Input boards (8 sensor inputs each)

Smart Case Controllers for liquid side or suction side control (each controls refrigeration, lights,

fans, defrost, and anti-sweat heaters for a single refrigerated fixture)

RTC Rooftop Control boards (each controls functions for a single RTU)

Device capacities for an AKCESS network are as follows:

Refrigeration ü 5 Suction Groups

ü 8 Compressors per suction group

ü 4 Unloaders per compressor

ü 1 variable speed motor control per suction group

ü 40 Circuits per suction group

ü 2 Heat reclaim stages per suction group

ü 5 Subcooling circuits

ü 5 Condensers (air cooled or evaporative)

ü 12 Fans per condenser (air cooled)

ü Variable speed condenser control

HVAC Up to 32 Systems (AHU, RTU, RTC, and Seasons4 Smart Coil units)

AHU’s & RTU’s ü Direct control using RO, VO, SI, and OI boards

ü 2-speed fan control (plus variable speed on AHU’s)

ü 6 Cooling stages per air handler

ü 5 Heating stages per air handler

ü 2 Heat reclaim stages

ü Analog gas valve control

ü 5 Dehumidification stages, including dessicant systems

ü Damper control

ü Multiple compressor control

ü Compressor and condenser control

Alternative RTU control ü Control via Rooftop Control (RTC) Board (has standalone capability)

ü 1 Fan stage

ü 3 Heating stages

ü 3 Cooling stages

ü 1 Damper or economizer

Lighting ü 30 Lighting zones

ü 6 relays per zone

ü Standard or relative schedules

ü Up to 8 schedules per zone

ü Automatic override for burglar or fire alarm

ü Switch override with OVR Override Box

Miscellaneous Points ü 20 Logic statements per AKC 55

ü 5 relays per statement

ü 20 Miscellaneous sensor inputs and on/off inputs

for monitoring and alarming

Switch Override Boxes ü 1 Box per AKC 55, 8 switch overrides per box

AKCESS System Manual RC.IU.B1.22 4/99.1 1-3

Non-AKCESS Nodes ü 5 EMON energy meters per AKC 55

ü 8 Bitzer (Echelon) compressor interfaces per suction group

ü 5 Square D Powerlink

(Echelon) panels per AKC 55 (42 breakers each)

ü 1 Danfoss VLT (Echelon) variable frequency AC drive per compressor, 1

per condenser group, and 1 per AHU

Demand Limitiing ü Using 1 of the EMON energy meters per AKC 55

Alarms ü Configurable for all inputs and outputs, plus system alarms

ü Delivered by modem, ethernet , and local printer

Office Alarm Boxes ü Up to 3 OAB-1’s per AKCESS system

History ü Up to 600 datapoints per AKC 55

Communications ü Local via RS 232

ü Modem using standard telephone line

ü Ethernet

Security ü 5 Authorization levels

ü 5 Account codes per level

1 - 4 System Manual RC.IU.B1.22 4/99.1 AKCESS

AKA 65 Danfoss AKA 65 AKCESS Network Supervisor

software is a system option which runs on any

PC with Windows for direct RS 232, modem , or

ethernet communication with any AKC 55 system.

It shows precisely the same screens, navigational

icons, and information that appear on the AKC

55’s LCD display, and for properly authorized

users, allows changes to AKCESS system

settings, collection of history, and

troubleshooting of an entire control system from a

single location.

A PC running AKA 65 Network Supervisor can be added to any AKCESS AKC 55 network. In

addition, Network Supervisor is used on remote PC’s to communicate with one or any number of

AKCESS AKC 55 networks by modem over standard dial-up telephone lines or ethernet networks.

Linking your PC to the AKCESS host network and using AKA 65 Network Supervisor software are

covered in Chapter 7.

AKC 55 An AKC 55 controller has two components: (1) a main CPU (central processing unit) board; and (2) a

PS/COMM (power supply and communications) board. Up to 15 AKC 55’s connected by and

communicating over an RS 485 bus make up an AKCESS system’s host network.

History History is collected and stored in the standard system and in optional memory modules of various

capacities.

Communications

Modem Optionally, a modem can be installed in any of the AKC 55’s in a network for remote communications

over a standard voice-grade dial-up telephone line.

Ethernet An AKCESS network can have one or two ethernet network connections.

Nodes Each AKC 55 can have up to 95 nodes in its I/O network, but there is a maximum of 99 nodes of each

type, since each board must have a two-digit address between 01 and 99. Nodes are principally input-

output boards and Danfoss Smart Case Controllers. TP-78K twisted pair cable (with shield) is used for

connecting the I/O network, both between nodes and to the host AKC 55.

Inputs and

Outputs Each AKC 55, with appropriate I/O nodes, can have up to: 256 relay outputs; 256 on-off inputs; 225

sensor inputs; and 225 variable outputs, using the boards described in the following Chapter.

Echelon

Interface Although the AKCESS system uses TPT Transceivers, a TPT-FTT bridge makes possible

interface to Echelon devices which use Free Topology Transceivers.

System Components

akc55box.dwg 2/99

AKCESS System Manual RC.IU.B1.22 4/99.1 1-5

Input and Output Boards

RO8

Relay Output

Board The RO8 provides eight relay outputs using class C relays, each with normally open, normally closed,

and common connections for general purpose control applications. RO8 relay outputs are fused at 5

amps. For each output relay, there is an LED which lights when the relay coil is energized.

RO8S

Relay Output Board

with Override Switches

The RO8S is electrically identical to the RO8 board just described, except that it is provided with a

three-position override switch for each output. The output is in automatic mode, controlled by the

AKC 55, when the switch is in the middle position. The relays can be overridden either to a coil-

energized state or to a coil-de-energized state.

OI8 & OIL8

On-off Input

Boards The OI8 provides eight general purpose on-off inputs (48-240 VAC) for device monitoring. The OIL8

provides low voltage inputs (9-80 VAC). Inputs are optically isolated and fused at 0.5 amp. Each

input has an LED which lights when input voltage is sensed.

1 - 6 System Manual RC.IU.B1.22 4/99.1 AKCESS

SI8

Sensor Input

Board The SI8 provides eight analog inputs (default range 0-6 VDC) for Danfoss sensors for temperature,

pressure, light level, and other analog measurements. Sensors from other manufacturers may be

compatible if they have an output range of 1-2, 0-5, or 1-6 VDC (you can select the range during

configuration). Readings from non-Danfoss sensors will be meaningful if they have one of the appropri-

ate output voltage ranges and a linear response. It is best to consult with your Danfoss representative

before using non-Danfoss sensors.

VO2

Variable Output

Board

The VO2 provides two analog outputs (0-10 VDC) for general purpose control of devices such as

variable speed compressors and motors, analog gas valves, and linear damper motors. The output can be

limited to a range of 0-5 VDC through software.

AKCESS System Manual RC.IU.B1.22 4/99.1 1-7

Dual I/O Boards RO8 Relay Output boards and OI8 On/Off Input Boards are available as dual boards. All

specifications including power requirements remain the same as for two individual boards. The

illustration shows an RO8D dual Relay Output Board.

OVR Override Box

Occasionally store personnel come in early, stay late, or

otherwise need light or seasonal HVAC at times when the

devices are normally scheduled off. The OVR allows them to

turn on lights at these times for a pre-determined period.

Each OVR has eight switches. Each switch is assigned to a

lighting zone or HVAC device for which override capability is

desired. During lighting and HVAC configuration, each is

assigned an override time in hours and minutes (up to 23

hours 59 minutes).

One or more OVR’s can be used depending on how many

zones or HVAC devices need to have override capability.

Each OVR

Override Box counts as one node in the 95 node capacity of

the I/O etwork.

OAB-1 Office Alarm Box

When an Office Alarm Box is connected to your AKCESS

system, audible and visual notification of an alarm situation

can be received locally.

When an alarm is generated, a small red LED on the OAB

lights and an intermittent beeper sounds. The sound can be

turned off with the “Silence” switch, but the red light will

remain on as long as the alarm condition exists.

The OAB is NOT one of the nodes on the I/O network;

1 - 8 System Manual RC.IU.B1.22 4/99.1 AKCESS

it is connected to a relay output.

Smart Case Controllers

In Smart Case Control, all fixture functions (refrigeration, defrost, fans, anti-sweat heaters, and lights) are

regulated by a single Danfoss AKC 164SC controller located in the fixture itself. The Smart Case

strategy allows each evaporator and associated functions in the same fixture to be individually controlled,

independent of other fixtures in the line up. Danfoss Smart Case Controllers, valves, and sensors are

pictured below.

There are various benefits to the Smart Case Strategy, including more appropriate and constant product

environment; installation savings on materials and labor; energy savings; remote monitoring and alarming

capability; and diagnostic and service benefits.

As appropriate for the type of fixture, Danfoss Smart Case Control can be liquid side control using a

Danfoss AKV electronic expansion valve or suction side control using a Danfoss KVQ electronic

evaporator pressure regulating valve with thermostatic expansion valves.

Liquid Side

Control Liquid side control is achieved with an AKC 164 Smart Case Controller and an AKV 10 or AKV 15

electronic expansion valve. An AKV valve regulates liquid supply to the evaporator so that injection is

optimum under all operating conditions. Liquid injection is governed by an adaptive software algorithm

in which the difference between the evaporator’s inlet and outlet temperatures is compared with a

reference superheat. The optimal superheat varies with changes in operating conditions, so the Smart

Case Controller varies the reference superheat according to those same conditions.

Minimum and maximum reference superheat are factory set. The range limits normally do not need to

be changed. Superheat adjustment by the controller is completely automatic.

AKV 10 and AKV 15

Electronic Expansion Valves

The AKV is a solenoid valve with a built-in expansion orifice and

a dampening device. Dampening increases the valve’s longevity; the

AKV’s tested lifetime is in excess of fifty million cycles. The AKV 10

does not modulate, but is fully opened when refrigeration is called

for. Thus refrigerant always enters the coil at full velocity, improving oil

return.

AKCESS System Manual RC.IU.B1.22 4/99.1 1-9

AKV 10 and AKV 15

Pulse Width

Modulation AKV valves operate on the principle of pulse-width modulation. The valve is cycled in six second

periods. During operation, the valve opens for some percentage of each period (from 0%, when there is

no need for refrigeration, and the valve remains closed for the entire six seconds, to nearly 100%, when

full refrigeration capacity is required). The percentage of the period for which the valve is open is based

on changes in load as determined by measured variations in superheat.

Temperature

Control With liquid side Smart Case Control, you can use the standard target with +/- range temperature strategy

or, where extremely tight fixture temperature control is critical (for example, in meat and fresh fish cases)

you can order the modulated temperature control option for your Smart Case Controllers. Modulated

temperature control is a unique approach which allows regulation as close as ±½

Suction Side Control Where suction side control is desired, as it may be in service meat

cases or when there are multiple evaporators in a single fixture, an

AKC 164 Smart Case Controller controls a Danfoss KVQ electronic

EPR valve on the suction side. Thermostatic expansion valves are

used on the liquid side of the evaporator.

KVQ Electronic

EPR Valve The Danfoss KVQ is an electronic evaporator pressure regulating valve which operates on a heat motor

principle, and is available with or without a right-angle copper outlet extension. The complete assembly

consists of a valve body and actuator.

Defrost Control Standard Smart Case Control defrost strategy includes time-initiated defrost with termination by time or

by temperature with time-duration fail-safe. Where defrosts for multiple evaporators in the same line-up

are scheduled at the same time, and where there are no dividers between the fixtures, the Coordinated

Defrost Function can be used to insure that there is no conflict between refrigeration and defrost. In

other words, Smart Case Controllers operating under Coordinated Defrost on the same schedule all

return to refrigeration at the same time.

Intelligent

Defrost Intelligent Defrost is an optional new strategy developed by Danfoss for use with its AKV valves. With

Intelligent Defrost, no additional hardware is required. If a scheduled defrost is determined to be

unnecessary, that defrost is skipped. Contact Danfoss for application information and availability.

AKS 16

Drain Sensor When fixtures are equipped with Danfoss AKS 16 Drain Sensors, Smart Case Controllers will give early

warning at the first signs of a plugged drain.

Fan Control Fans can be programmed to stop during defrost and to delay re-starting after defrost termination.

1-10 System Manual RC.IU.B1.22 4/99.1 AKCESS

Anti-Sweat

Heater Control Control of anti-sweat heaters is based on dewpoint. High and low dewpoint limits are selected. Above

the high limit, anti-sweat heaters are on continuously; at and below the low limit, they are kept off.

Between the limits, the heaters are turned on for a part of each time cycle. The actual time the heaters

are on is dependent upon how close the dewpoint is to the upper or lower limit. You select the length of

the time cycle and the upper and lower limits during configuration.

A high temperature safety cut-out can be set up so that when a user-specified high temperature is

sensed, the anti-sweats will be shut down and prevented from operating until fixture temperature is once

again safe.

Lighting Control An AKC 164 controls fixture lights based on schedules you create during configuration. Lights can be

configured to be off during defrost if necessary.

Danfoss AKC 55 System Installation guide

Danfoss AKC 55 System Installation guide

Danfoss AKC 55 System Installation guide

Related papers

Other documents