Vertiv Liebert HPW Series, Руководство пользователя

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pag. 4
more than 50% for over 2 minutes, the Freecooling mode
is de---activated for 1 hour, and the unit shifts to cooling by
means of the refrigerating compressor.
Fig. c) Compressor, heater and damper opening
operation
Set Cooling Heating _C
Set Cooling Heating
_C
Freecooling
mode
Compressor
cooling mode
P Band
P Band
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 microprocessor
control. 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 en-
able an even wear of the system components.
If the system is connected with the graphic interface, it is possible
to set a different rotation control. Activating the Cascade function, if
several units are simultaneously 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 sequential
on the different units forming the system, and precedes the pos-
sible 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---microprocessor
control
Set
_C
Cooling Heating
3
1
2
3
1 1
2 2 3
Freecooling mode
P Band
Set
Compressor cooling mode
P Band
_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:
- compressor low pressure
- compressor high pressure (reset on the pressure switch)
- sensor fault
- memory fault
- fan fault
2) General warning (lowest priority), including:
S high temperature
S low temperature
Note :
- An alarm causes the unit to stop and the unit in stand---
by (if available) to intervene.
- A warning does not stop the unit.
- Both the alarm and the warning activate sight and
sound signals.
- Both the alarm and the warning must be reset manually
on the microprocessor control.
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 configur-
ation, 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) Indoor air clogged filter alarm
5) Fan fault
These alarms control unit in the same way as described in
the previous paragraph.
For the detailed description of the alarms, see the
micropro-cessor manual enclosed.
7 --- Calibrations
- The air conditioner has already been factory ---tested
and calibrated as described below (see Tab. 8).
- For the Microprocesso Control calibrations refer to the rel-
evant manual (to avoid wrong operations do not use
tem-perature and rel. humidity set points/proportional
bands which differ excessively from the standard
settings).
7.1 --- Environment protection
A misuse or an incorrect calibration of the unit leads to
in-creased energy consumption, resulting in an economic
and environmental damage. Use the freecooling function, if
avail-able.