Danfoss AKC 55 System Installation guide

Brand: Danfoss

Model: AKC 55 System

Type: Installation guide

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

Chapter 2 Control Network Layout

An AKC 55 control system has two network levels: the host network, consisting of the AKC 55

controllers communicating over an RS-485 bus, and an I/O network consisting of all the input and

output boards and Smart Case Controllers, which communicate over an Echelon TP-78K twisted-pair

bus.

A single AKC 55 can control every type of system in a supermarket, and often, one AKC 55 is used to

control an entire store. Sometimes, one AKC 55 is used for each refrigeration rack to control and

monitor the compressors, condenser, and each refrigeration circuit. When Smart Case Control is

implemented, Danfoss Smart Case Controllers are also connected to the rack’s AKC 55.

Additional AKC 55’s are put on the network to control packaged or built-up HVAC systems, lighting,

and other site subsystems.

Host Network Up to 15 AKC 55’s can be connected in an AKCESS network, using cable that meets RS-485 specifica-

tions (see below). The total length of the host network cable is limited to 1000 feet. The host network

must be wired point-to-point, without branching. Both the first and last AKC 55’s must be terminated

as described in the installation section.

Cable Requirements

RS 485 Host Network For the host network, use 3-conductor stranded shielded wire, AWG 18. Connect

the shield to the “SHIELD” or “GND” terminal ONLY at the first AKC 55.

At each controller between the first and last ones on the network,

wirenut the shields together so that the shield is continuous, and insulated from

ground, for the entire length of the network. Leave the shield loose at the last controller,

but insulate it from ground.

Keep the host network of AKC 55's to

1000 feet or less. Wire it point-to-

point with no branching. Terminate

the first and last AKC 55's.

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

I/O Network Up to 120 nodes can be connected to each AKC 55. The nodes are joined point-to-point (“daisy-

chained”), using up to five TP-78K (twisted-pair) cable runs per AKC 55. When necessary, nodes can

be placed on branch “stubs” up to 25 feet long off a main twisted-pair cable run. A TP-78K cable run

can be up to 5000 feet in length including the lengths of any branch stubs, but the total of all cable runs,

including stubs, must not be over 5000 feet. A terminator must be placed at the end of each of the five

main cable runs. Do not put terminators on stubs.

Cable Requirements

TP-78K (twisted-pair)

I/O Network

I/O network cable must be stranded twisted pair with a shield. Use Belden number 8761 (22 AWG),

8762 (20 AWG), 9461 (22 AWG), 9464 (20 AWG), 9841 (24 AWG). If none of the listed types is

available, an equivalent may be used.

Make up to 5 I/O runs, but the

total length of all the runs cant

be more than 5000 feet !!

Remember to terminate the last

board on each main run !!!

Danfoss AKC 55 System Installation guide

Danfoss AKC 55 System Installation guide

Danfoss AKC 55 System Installation guide

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