![background image](http://html1.mh-extra.com/html/johnson-controls/unisab-iii/unisab-iii_operating-manual_2023543007.webp)
1. Operating Unisab III control
1.1. Introduction
The purpose of the Unisab III control system is to monitor, protect, control and regulate re-
ciprocating and screw compressors. The control cabinet as well as the electrical components
have been connected from factory. Thus, only a few connections are needed to link to the
electrical installations on site.
Unisab III is programmed according to the type of compressor it is going to control. See sec-
tion Setup (Engineering manual).
Unisab III offers different ways of controlling/regulating compressor capacity according to
pressure levels or temperatures. Compressor capacity can be regulated both manually and
automatically.
Furthermore, a number of limiting functions have been incorporated. In periods of overloading
these limiting functions will intervene and limit compressor capacity until the situation has re-
turned to normal. Consequently, the number of undesirable operational stops will be reduced
as well as the need for supervision.
Compressors fitted with Unisab III Control can be linked via the built-in communication sys-
tem, Multisab. In this way compressors can work in a common refrigerating system, thus op-
timizing the operation of the entire compressor plant.
The communication system further allows Unisab III to be connected to a PLC or PC central
monitoring, control and data logging system. Unisab III can be linked to and communicate
with former Sabroe control units such as Unisab II.
Unisab III is operated by means of a front panel as shown in Fig. 3. The front panel is well-
arranged with only a few keys and a distinct display.
Unisab III does not lose its preset or changed values in the event of a temporary power fail-
ure. It contains a battery which is used by the built-in timer to ensure that time and date are
always correct even if power has been disconnected. The hour counter and any stored alarm
values will maintain the correct time.
1.1.1 Start-up
On delivery all electrical components in the compressor are connected to Unisab III. On site it
is only necessary to add the correct supply voltage from the local installations. The electric
wiring must be carried out according to the wiring diagrams for Unisab III at the end of this
manual.
Note in particular that
•
no outside voltage must be applied to the digital inputs of Unisab III.
•
the supply voltage must be between 85 VAC and 250 VAC.
Before any voltage is applied to Unisab III, the emergency stop switch must be activa-
ted. When voltage is applied to Unisab III, the default picture shown below will appear in the
display and Unisab III will be ready for operation.
Operating Unisab III control
Operating manual - Unisab III
005650-en 2013.10
5/48
Содержание Unisab III
Страница 1: ...Op er at in g m an ua l Version 1 10 Unisab III Control en...
Страница 2: ......