AERMEC Multichiller User manual

multi chiller
English
UNIQUE MANUAL
Control system for the management of several chillers
0609 - 5148051_01

2
DO NOT let the
packaging get wet DO NOT tread on the packaging Handle with care
Safety symbols
!
Danger - voltage Warning Danger - moving
parts
Precautions and safety regulations
Keep the manuals in a dry place - to maintain their good condition - for at least 10
years, for any future reference needs.
Read all the information in this manual carefully and completely. Pay special at-
tention to the user regulations marked by the words “DANGER” or “WARNING”,
as these points could cause damage to the machine and/or persons and property
if not observed. For any irregularities not foreseen by this manual, promptly
contact your local After Sales Service.
The equipment must be installed in such a way as to facilitate any maintenan-
ce and/or repair operations.
The
manufacturer cannot accept any responsibility for any damage resulting from
the improper use of the machine, or from the partial or superficial reading of the
information contained in this manual.
Warning: this product contains electric and
electronic equipment that cannot be scrapped
via the normal waste collection channels.
There are special differentiated collection
points for these products.
The electric and electronic equipment must be
handled separately, and in accordance with the
legislation in force in that specific country.
Batteries or accumulators in the equipment
must be scrapped separately, in accordance
with the regulations in that specific municipa-
lity.
Disposal information Note sulla manualistica
EC declaration of conformity notes
The accessory described in this manual may only be used in
combination with the machine for which it has been designed.
The EC declaration of conformity of the equipment to which it
will be integrated is valid when this condition is satisfied. Refer
to the manual provided with the unit in order to check the list of
compatible accessories.

Index
Introduction 4
Multichiller Architecture 5
Multichiller -- PCO2 Interface Hardware 6
Multichiller -- GR3 Interface Hardware 7
PCO1 Input/Output cards 8
PCOE Input/Output cards 8
User interface 9
Description of physical key function 9
Description of virtual key functions 10
Main menu 10
User Menu 11
Display Menu 14
Setup Menu 17
Adjustment logic 23
Adjustments for load : LOAD 23
Adjustments for load: TEMPERATURE 25
Timers 26
Rotation 27
Multifunction inputs 27
Double Set point 28
Priority Set point 28
Multichiller Alarms 29
Setup cards 31
PCO2 (Chiller) 31
GR3 (Chiller) 31
Electric connections 32

4
IThe maximum number of units that can
be connected to a Multichiller is Max 9
RVBH (each of which up to 4 compres-
sors) or Max 9 NRA (NRC, NLW, NBW)
Chiller unit means the following fami-
lies of models :
• NRA
• NRC
• NLW
• NBW
• RVBH
• NSB
• WSB
• NRL
Introduction
The scope of this project is to a realise
a control system (which hereon will be
called Multichiller) for the switching on
and off of chillers in a plant where seve-
ral chillers are installed parallel to each
other with constant water flow on the
individual evaporators.
It is possible to chose between different
chiller switch on/off logics:
Sequential: the chillers are switched on/
off one at a time (possible if each chiller
has its own pump that is switched on/off
with it)
Homogeneous: the chillers are switched
on/off at the same time (recommended if all
of the chillers have the same pump)
Combined: the chillers are switched
on and taken to a certain power that is
lower than maximum before switching
on others. (possible if each chiller has
its own pump that is switched on/off
with it)
The Multichiller regulates using its own tem-
perature probes. Once a chiller has been
switched on it uses its own temperature pro-
bes to regulate in an independent manner
from the others until it is switched-off by the
Multichiller itself.
3) Centralisation of information regar-
ding the state of the machine in a uni-
que display
ON/OFF
• Set point
• Detailed chiller alarms
• Chiller temperature and pressures
• Choking level of individual chillers
4) Management of chiller rotation with
possibility of maintaining the machine
as per emergency
• Rotation for balancing compressor
work hours
• Rotation for alarms
• Chiller switch-on sequence selection
can be set
5) Possibility of keeping a chiller as a
reserve in case of breakdown
Multichiller exclusive functions
In particular, the additional functions
performed by the Multichiller that are
not available for the management of
individual chillers, are the following:
1) Regulation of water temperature in a
unique point.
• Connection of plant water input and
output probe to the Multichiller
• Adjustment on the plant primary or
secondary (depending on the type of
plant)
• Pulldown (delays between the activa-
tion of one compressor and another)
• Introduction and disconnection of the
chillers (not of the individual compres-
sors) on the basis of the load
• Introduction in tandem, in parallel or
mixed
2) Centralised setting of the main func-
tioning parameters:
• ON/OFF
• Hot/Cold functioning
• Work set point:
- From analogue input, from keyboard
• Proportional band
• Timer
• Demand Limit:
- From analogue input
• Set point compensation:
- external air probe (optional for set
point compensation)
- from analogue input

5
display PGD3
scheda PCO1
interfaccia PCOE
sonde
chiller Prg
Esc
320X240 pixel
Colori
Touch screen
320X240 pixel
Colori
Touch screen
Programming Key
Fuse
Prg
Esc
Programming Key
Fuse
Multichiller architecture
• It is a PCO1 controller and PGD3 touch screen display:
The product is supplied in
IP55 box with transparent
observation window

6
Programming Key
Fuse
Programming Key
Fuse
BMS
Prg
Esc
Programming Key
Fuse
Programming Key
Fuse
Programming Key
Fuse
chiller 1 chiller 2 chiller N
master master mastersla e 1 sla e 2
modbus
multichiller
MODBUS RS485
interfaccia
AER485P2
Multichiller/PCO2 interface hardware

7
chiller 1
BMS
modbus
multichiller
Prg
Esc
chiller 2 chiller N
-
SET
R
C1
C2
+
LR
-
SET
R
C1
C2
+
LR
-
SET
R
C1
C2
+
LR
AER485 AER485 AER485
Multichiller/GR03 interface hardware

8
PCO1 card Inputs/Outputs
ANALOGUE INPUTS FUNCTION TYPE OF INPUT
B1 Multifunction input 0 - 20 mA
B2 Multifunction input 0 - 5 Vcc
B3 Multifunction input NTC 10k Temperature probe
B4 SIW NTC 10k Temperature probe
B5 SUW NTC 10k Temperature probe
B6 SUW2 NTC 10k Temperature probe
N.B: SUW3 cannot be managed without PCOE
DIGITAL INPUTS FUNCTION
ID1 Not used
ID2 Not used
IDI3 Enabling of double set point (2° Set) Contact closed = double set enabled
ID4
Enabling of multifunction inputs (Mult) Contact closed = multifunction enabled
ID5 Flow meter 1 (FL1)
ID6 Flow meter 2 (FL2)
ID7 Flow meter 3 (FL3)
ID8 Not used
DIGITAL OUTPUTS FUNCTION
ID1 Summary of chiller and Multichiller global alarms
ANALOGUE OUTPUTS FUNCTION
Not used
PCOE card Inputs/Outputs
ANALOGUE INPUTS FUNCTION TIPO INGRESSO
B1 SIW NTC 10k Temperature probe
B2 SUW NTC 10k Temperature probe
B3 SUW2 NTC 10k Temperature probe
B4 SUW3 NTC 10k Temperature probe
DIGITAL INPUTS FUNCTION
Not used
DIGITAL OUTPUTSI FUNCTION
Not used
ANALOUE OUTPUTS FUNCTION
Not used

9
A
B
C
D
E
F
G
Esc
Prg
Prg
Esc
User interface
KEY FUNCTION
A - C These keys are used to scroll a menu mask. From the last access the first
and vice versa. If the cursor is inside a numerical field the keys increase or
decrease the value on which the cursor is positioned. If it is a selection field,
by pressing the UP/DOWN keys the options available are visualised (e.g. Yes
/ No)
B In the value setting masks, by pressing the key once, the cursor moves onto
the first introduction field. When pressed successively, the value set is con-
firmed and the cursor moved to the following field. The cursor is hidden from
the last field
D No function
E When pressed once it allows visualisation of the alarms that have intervened
and switches off the alarm buzzer. When in alarm visualisation, pressing a
second time determines alarm/s reset. If there are no alarms go to the NO
ALARM ACTIVE mask. The sequence of the alarms is given by pressing the
UP/DOWN keys.
F No function
G Go back to main menu from any menu
The user interface is made up of a 320x240 pixel colour touch screen graphical
display.
The keys used to access the various menus can therefore be of two types:
Physical, the traditional keys on the keyboard at the right of the screen.
Virtual, the keys represented graphically on the display that can be “pressed” by
simply touching them (and not pressing) the area of the display in which they are
represented.

10
Prg
Esc
Prg
Esc
Main menu
Note:
Virtual COMMAND key: Access to the user menu from where it is
possible to perform all control actions on the plant (chiller set poin-
ts, programming clock reset alarms, on/off of the individual units
etc.)
Virtual DISPLAY key: Access to the plant synoptic page in which the
main information regarding the functioning state of the plant are
supplied briefly and clearly as graphics..
Virtual SETUP key: Goes to the installation menu where the para-
meters for the definition of the plant and the type of check to be
carried out are set.
A virtual key appears in the plant synoptic window (identified by a small
chiller) for every chiller present in the plant. Access the chiller menu by
pressing the corresponding icon. This displays the data relative to the
individual chiller in detail.
General state:
On = plant on
Off by timer = plant off due to time period
Off by keyboard = plant switched-off by
Multichiller disable = the management of the multichiller on the plant
is disabled and all chillers are in ON, the multichiller only functions as a
data supervisor.

11
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
USER Menu
Note:
Chiller 2° Cooling Set: second cold functioning mode set point that
can be used as an alternative to the first if the function is enabled
Chiller 2° Heating Set: second heat pump functioning mode set
point that can be used as an alternative to the first if the function
is enabled
Note:
Multichiller Enable: enables chiller introduction/disconnection. If
OFF, all chillers are requested always switched-on, independently
from the temperatures detected. Time period controls, global on/off
and switching-off of the individual chillers remain always active. The
Multichiller with this parameter in OFF only functions as plant super-
visor
Global On/Off: centralised switch on/off control of all chillers.
Chiller Cooling Set: cold functioning mode set point that is set for all chil-
lers
Chiller Heating Set: heat pump functioning mode set point that is
set for all chillers
Actual Cooling Set: cold functioning mode set point used currently by
the chillers (can be different to Chiller Cooling Set as the double set
point or multifunction input could be used to determine the work set
point)
Actual Heating Set: heat pump functioning mode set point used
currently by the chillers (can be different to Chiller Heating Set as
the double set point or multifunction input could be used to deter-
mine the work set point)

12
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Note:
External Cooling Set : visualisation of the cold set point obtained
from analogue input if function enabled
External Heating Set: visualisation of the hot set point obtained
from the analogue input if function is enabled
External Chiller Demand: visualisation of the 0-100% power reque-
sted by analogue input if function is enabled
External Limit: visualisation of the power limit from analogue input
if function is enabled
External Compensation Cool: visualisation of cold set point compen-
sation obtained from analogue input if function is enabled
External Compensation Heat: visualisation of hot set point compen-
sation obtained from analogue input if function is enabled
Note:
This window allows access to alarms reset of the individual chilers. A chiller
icon appears for every chiller present in the plant at the side of the touch
screen reset button. By pressing the reset button the request to reset alarms
is started for the relative chiller, which requires a few seconds
Note:
This window allows access to the On/Off control of the individual chillers. A
chiller icon appears for every chiller unit present in the plant at the side of the
touch screen On/Off button. By pressing the reset button, the unit switches
on or off. The programme considers eventual unavailability of the chiller positio-
ned in Off in the chiller rotation

13
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Note:
Weekly time programming: In this window it is possible to set time, date and
day of the week.
Enable weekly timer: enabling of the plant’s weekly programming
Status timer On/Off: indicates if the plant is switched on or off by the
weekly time programming. When programming is disabled the status is
always On.
Note:
Day: selects the day of the week for which the time period is to be
set.
Start1 : plant switch-on time for the first period
Stop 1: plant switch-off time for the first period
Start 2 : plant switch-on time for the second period
Stop 2 : plant switch-off time for the second period

14
Note:
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
SUW
chiller 1 - 9
Stato
chiller 1 - 9 SUW SUW2 SUW3
FL
FL2
FL3
SIW
Prg
Esc
Prg
Esc
SUW
chiller 1 - 9
SUW
Stato
chiller 1 - 9
SIW
DISPLAY Menu
Note:
This window clearly displays the state of the
plant. Two different synoptics are available
to represent the plant’s operating principle
in a more appropriate manner, which can be
selected from the Setup menu, page 4. Enable
display circuit 1/2
Note:
IThe primary circuit is represented in this synop-
tic in blue and the secondary in red, separated by
a hydraulic disconnecting device in black
SIW: return water temperature to the primary. It
is read by the Multichiller
SUW, SUW2, SUW3: delivery temperatures to
the secondary circuit. Up to 3 branches of the
secondary circuit can be managed for secon-
daries with variable chiller. They are read by the
Multichiller.
FL, FL2 FL3: used to enable reading of the res-
pective probes for delivery to the secondary, if
the flow meter contact is open it is not taken into
consideration when adjusting the temperature
of the respective probe. They are read by the
Multichiller.
SUW chiller 1-9: the temperature of the water
exiting the chiller is stated at the side of the icon
of every chiller present and is read via serial. In
the case of machines from the following series
NRA, NRC, NLW and NBW it is the only chiller
water evaporator exit probe; in the case of RV,
NSB, NW, WSB machines it is the Master card
evaporator exit probe B5.
Chiller state 1-9: an icon is visualised that is also a
touch screen key for each chiller from 1 to 9 with
the following meaning:
Chiller not present
Flashing = chiller ON
Fixed = chiller standby
Chiller with circuit in alarm
Chiller with all circuits in alarm
Chiller with which it is not possible
to communicate
By pressing the icon key of each chiller,
access the visualisation menu of the details
of the relative chiller. This page appears for
a few seconds during loading of the data if
the chiller is present. If the chiller is not pre-
sent (the icon of a blue square is pressed)
this page remains indefinitively.

15
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Type of machine NRA, NRC, NLW, NBW
Note:
Temperature and pressure inputs, the abbreviations correspond to
those on the display
Note:
Chiller model
Serial address
On/Off state of the chiller and functioning mode
Circuits 1 and 2 alarm summary, the flashing symbol LED indicates an
alarm is present
Compressor state
Note:
Alarms present (the symbol flashing LED indicates alarm presence)
page 1
Note:
Alarms present (the symbol flashing LED indicates alarm presence)
page 2

16
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Type of machine RV, RVB, NW, NSB, WSB
Note:
Temperature and pressure inputs, the abbreviations correspond to
those on the display
Note:
Chiller model
Serial address
Card selection : Master, Slave 1,2,3 if present
On/Off state of the chiller and functioning mode
Circuits 1 and 2 alarm summary, the symbol flashing LED indicates an
alarm is present
Compressor state
Note:
Alarms present (the symbol flashing LED indicates alarm presence)
page 1
Note:
Alarms present (the symbol flashing LED indicates alarm presence)
page 2

17
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
SETUP Menu
Note:
Setting of plant chiller serial addresses. The addresses that have been assigned to the chiller are set. For RV, RVB, NW, NSB, WSB
series machines, it is also possible to set the addresses of the cards relative to the compressor slaves if they have AER485P2
interface. The valid addresses are from 1 to 255, the order or the adjacency have no influence.
N.B. The address 1 is reserved for the pCOE expansion card, if present, otherwise it can be used for a chiller.
Note:
Chiller 1-9 selection of the presence and type of chiller up to a maximum of 9
NONE : no chiller
NRA: for NRA, NRC, NLW, NBW chillers, all those with GR3 circuit board
RV: for RV, NW, RVB, NSB, WSB chillers, all those with pCO2 circuit board
N° Slave: for RV-type chillers, it is possible to connect up to 4 com-
pressors (1 Master + 3 Slave) therefore up to 4 pCO2 cards. If the
slaves are also equipped with AER485P2 interface, it is possible
to connect them to the network and visualise the data relative to
them. In this case, the consequent parameter is set. However, con-
nection of the slaves is not indispensable for correct functioning of
the Multichiller.
Note:
On = pCOE expansion enabled, SIW and SUW probes connected to the pCOE
Selection of the synoptic to be visualised in the Display Menu, with just pri-
mary circuit or primary and secondary circuits.

18
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Note:
Check on the basis of the load:
Delta T of a chiller at full power
Minimum choke of a chiller
Choke of chillers switched-on, beyond which the next is introduced.
Choke within which the chillers must remain switched on after one
has been disconnected.
Note:
Adjustment selection for Load or Temperature)
Filter on the holding of the increase or decrease condition of the num-
ber of chillers.
Minimum delay between switch-on of two chillers
Minimum delay between switch-off of two chillers
Note:
Check on the basis of the load:
Advance of the reset set point reset before switch-off of a chiller
Permanence of the reset set point after switch-off of a chiller
Value of the reset set point (to add to the set point)
Note:
Check on the basis of the temperature:
Settings for the functioning mode when cold
Temperature of the SUW probe/s (delivery) above which the introduc-
tion of a chiller is requested
Temperature of the SIW probe (return), below which the disconnec-
tion of a chiller is requested. This temperature is different depending
on the number of chillers switched-on

19
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Note:
Rotation of fixed chillers from 1 to 9 or on the basis of working hours
of the compressors
Selection of a reserve chiller from 1 to 9. It will only be introduced if
one of the chillers goes into alarm
Note:
Type of analogue input malfunction: NTC, 0-20mA, 0-5V
(NTC is a 10kohm temperature probe)
Use of the analogue input:
NONE
Set point = set hot or cold
Comp. Set point = hot or cold set point compensation
Limit = setting a max number of chillers
Demand = request number of chillers switched-on
Note:
Type of analogue input malfunction: NTC
Minimum temperature
Maximum temperature
Note:
Check on the basis of the temperature:
Settings for the functioning mode when hot
Temperature of the SUW probe/s (delivery), below which the intro-
duction of a chiller is requested
Temperature of the SIW probe (return) above which the disconnec-
tion of a chiller is requested. This temperature is different depending
on the number of chillers switched-on

20
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Prg
Esc
Note:
Type of analogue input malfunction: 0-20mA
Minimum current
Maximum current
Note:
Use of the multifunction input as Set point
Cold set point when the input is at maximum
Cold set point when the input is at minimum
Hot set point when the input is at maximum
Hot set point when the input is at minimum
Note:
Use of the multifunction input as Set point
Cold set point when the input is at maximum
Cold set point when the input is at minimum
Hot set point when the input is at maximum
Hot set point when the input is at minimum
Note:
Type of analogue input malfunction: 0-5V
Minimum voltage
Maximum temperature