English
pag. 4
6.4 --- LAN local network management:
Stand---by and Cascade modes
The control of the units in stand---by is completely automatic,
thanks to the possibility of connection with the Microface con-
trol. A unit in stand---by is automatically activated in case of
alarm locking the main unit; this occurs even if the main unit is
switched off or disappears from the system due to a failure on
the control connecting network (bus).
The hourly rotation of the stand---by units occurs automatically
every 24 hours, so as to enable an even wear of the system com-
ponents.
If the system is connected with the Hiromatic interface, it is pos-
sible to set a different rotation control.
Activating the Cascade function, if several units are simulta-
neously on with the same Set Point, the temperature used for
the control is the average of the detected ones: in cooling mode,
the proportional band is divided in as many parts as the double
of units belonging to the system, so as to shut the total available
refrigerating capacity.
The activation of the Freecooling mode (if installed) is sequen-
tial on the different units forming the system, and precedes the
possible activation of the cooling with compressor.
The Fig. d), shown as an example, represents the operation of a
system formed by three units.
Fig. d) System with 3 units in cascade --- Microface control
Set
_
C
Cooling
Heating
3
Freecooling mode
1
2
3
Compressor cooling mode
1
1
2
2
3
P Band
P Band
Set
_
C
Cooling
Heating
6.5 --- Alarm control
The two alarm contacts available on the terminal board of the
electric board are:
1) General alarm (highest priority), including:
S
compressor low pressure
S
compressor high pressure (reset on the pressure switch)
S
sensor fault
S
memory fault
S
fan fault
2) General warning (lowest priority), including:
S
high temperature
S
low temperature
A further general warning is available in the unit equipped with
heating, signalling the following abnormal condition:
•
heater thermostat (reset on thermostat)
Note:
S
An alarm causes the unit to stop and the unit in stand---by
(if available) to intervene.
S
A warning does not stop the unit.
S
Both the alarm and the warning activate sight and sound
signals.
S
Both the alarm and the warning must be reset manually on
the Microface.
In case the safety heater thermostat intervenes, the reset must
be carried out on the thermostat, following the same instruc-
tions as before.
6.6 --- Alarm board
(optional)
Besides the components described for the standard configura-
tion, an alarm card --- which can be supplied as optional --- there
are relay contacts which have the following alarms:
1) compressor high and low pressure
2) High temperature
3) Low temperature
4) Clogged filter alarm
5) Fan fault
These alarms control the unit in the same way as described in
the previous paragraph.
For the detailed description of the alarms, see the Microface
manual enclosed.
7 --- Calibrations
S
The air conditioner has already been factory---tested and
calibrated as described below (see Tab. 5).
S
For the MICROFACE calibrations refer to the relevant manu-
al (to avoid wrong operations do not use temperature and
rel. humidity set points/proportional bands which differ ex-
cessively from the standard settings).
8 --- Maintenance / Spare parts
For safety reasons, clear the unit opening the
switch QS1 before performing any maintenance
operations
If installed:
AS THE HIROMATIC/MICROFACE FEATURES AUTOMATIC
RESTART (AFTER A SUPPLY INTERRUPTION) IT IS ADVISED
TO DISABLE AUTORESTART AND OPEN THE SWITCH QF1
AND QF2 (IF PRESENT) WHEN PERFORMING ANY MAINTE-
NANCE.
S
EverydaychecktheHiromatic/Microfacereadingsfortemper-
ature and, if shown, ambient relative humidity.
S
The Maintenance Programme described below should be
carried out by a skilled technician, preferably working under
a maintenance contract.
Summary of Contents for Liebert HIROSS TD 06
Page 2: ......
