Paul TAC4 DG + TCP Instruction Manual

Status: 06/2013
Operating Instructions
Please keep careful! Please keep careful!
Paul Wärmerückgewinnung GmbH
August-Horch-Straße 7
08141 Reinsdorf
Tel.: +49(0)375 - 303505 - 0
Fax: +49(0)375 - 303505 - 55
Germany
TAC4 DG + GRC
Control unit
Installation and maintenance

1
Table of contents
0Preamble................................................................................................................................. 3
1Introduction............................................................................................................................ 3
Safety ....................................................................................................................................... 3
1.1
Used symbols........................................................................................................................... 3 1.1.1
2Functionalities of the regulation .......................................................................................... 4
3Generell maintenance instructions...................................................................................... 5
Generell information................................................................................................................. 5
3.1
Generell schematic of the maxi-series..................................................................................... 5 3.1.1
Schematic of the T° sensors positioning in the maxi unit ........................................................ 6 3.1.2
Control panel 3 label located inside the cover ......................................................................... 6 3.1.3
4GRC wiring and funtionalites................................................................................................ 7
Installation of GRC................................................................................................................... 7
4.1
On wall installation ................................................................................................................... 8 4.1.1
In wall installation..................................................................................................................... 8 4.1.2
Wiring of GCR TAC4................................................................................................................ 9 4.2
Plug SAT MODBUS satellite on CB4 TAC4 DG ...................................................................... 9 4.2.1
Wiring diagram to connect the GRC TAC4 REC to the SAT MODBUS ................................ 10 4.2.2
4.2.2.1 Cable specifications ............................................................................................................... 10
4.2.2.2 Wiring several circuits on one GRC....................................................................................... 10
Power GRC TAC4.................................................................................................................. 11
4.2.3
Selecting the master .............................................................................................................. 11 4.3
Fan control ............................................................................................................................. 12 4.4
Time slots schedules ............................................................................................................. 13 4.5
Definition ................................................................................................................................ 13 4.5.1
Alarms .................................................................................................................................... 13 4.6
Alarm types ........................................................................................................................... 13 4.6.1
Alarm table ............................................................................................................................. 15 4.6.2
Wiring diagrams ..................................................................................................................... 16 4.6.3
Fire alarm ............................................................................................................................... 16 4.6.4
4.6.4.1 Configuration.......................................................................................................................... 16
4.6.4.2 Wiring diagram of fire alarm................................................................................................... 16
BOOST function..................................................................................................................... 17
4.7
Setup...................................................................................................................................... 17 4.7.1
Wiring diagram....................................................................................................................... 17 4.7.2
BYPASS function (free cooling) ............................................................................................. 17 4.8
Opening / closing of dampers (CT option) at inlet ................................................................. 18 4.9
Heat exchanger antifrost protection system .......................................................................... 18 4.10
Protection antifreeze via pulse flow reduction ....................................................................... 18 4.10.1
Antifrosting the heat exchanger with 1 pre-heating KWin (option) ........................................ 19 4.10.2
KWout post heating electrical coil control (option)................................................................. 20 4.11
Wiring diagrams ..................................................................................................................... 20 4.11.1
Post heating (NV option) regulation....................................................................................... 20 4.12
Wiring diagrams ..................................................................................................................... 21 4.12.1
Regulation for external coil(s) (SAT TAC4 BA/KW option).................................................... 22 4.13
Fan failure alarm .................................................................................................................... 23 4.14

2
Actual airflow / pressure output signals ................................................................................. 23 4.15
5Configuration and use......................................................................................................... 24
Principles of GRC TAC4 ........................................................................................................ 24
5.1
Setup and fan control ............................................................................................................. 25 5.2
CA mode: setup, operating instructions and wiring diagrams................................................ 25 5.2.1
5.2.1.1 Setup CA mode...................................................................................................................... 25
5.2.1.2 Operating CA mode with GRC TAC4 master (‘Control’ screen) ............................................ 27
5.2.1.3 Operating CA mode with TAC4 DG master ........................................................................... 27
LS mode: setup, operating instructions and wiring diagrams ................................................ 28
5.2.2
5.2.2.1 Setup LS mode ...................................................................................................................... 28
5.2.2.2 Operating LS mode with GRC TAC4 master (‘Control’ screen)............................................. 30
5.2.2.3 Operating LS mode with TAC4 DG master............................................................................ 31
CPs mode: setup, operating instructions and wiring diagrams.............................................. 32
5.2.3
5.2.3.1 Setup CPs mode .................................................................................................................... 32
5.2.3.2 Operating CPs mode with GRC TAC4 master (control screen)............................................. 34
5.2.3.3 Operating CPs mode with TAC4 DG master ......................................................................... 35
Mode OFF .............................................................................................................................. 35
5.2.4
Time slots schedules.............................................................................................................. 36 5.3
«Setup» tab............................................................................................................................ 36 5.3.1
«Week planner» tab ............................................................................................................... 37 5.3.2
«Year planner» tab (seasonally or yearly planner) ................................................................ 37 5.3.3
Network management ............................................................................................................ 37 5.4
General................................................................................................................................... 37 5.4.1
Network Visualization............................................................................................................. 38 5.4.2
Edit a network ........................................................................................................................ 38 5.4.3
5.4.3.1 Screen description ................................................................................................................. 38
5.4.3.2 Method ................................................................................................................................... 38
Visualization ........................................................................................................................... 39
5.5
«Synoptic» tab ....................................................................................................................... 39 5.5.1
5.5.1.1 General information................................................................................................................ 39
5.5.1.2 Air «Flows» tab ...................................................................................................................... 40
5.5.1.3 Post heating information (if NV or KWout or BA+ option present)......................................... 40
5.5.1.4 Anti-frost information .............................................................................................................. 42
5.5.1.5 Damper(s) (CT) information (option)...................................................................................... 42
«Alarms» tab .......................................................................................................................... 43
5.5.2
«Setup» tab............................................................................................................................ 43 5.5.3
«Flows» tab............................................................................................................................ 44 5.5.4
«I/O» tab................................................................................................................................. 44 5.5.5
«Config» tab........................................................................................................................... 45 5.5.6
Advanced setup ..................................................................................................................... 45 5.6

3
0 Preamble
PLEASE READ THIS MANUAL CAREFULLY BEFORE INASTALLATION AND COMMISSONING!
THIS MANUAL HAS BEEN MADE WITH GREATEST CARE.
HOWEVER, NO RIGHTS CAN BE DERIVED THEREFROM. WE RESERVE THE RIGHT AT ANY TIME
TO PARTIALLY OR ENTIRELY CHANGE THE CONTENT OF THIS MANUAL WITHOUT PRIOR
NOTICE.
This manual contains all the best for an assembly plant and a heat recovery unit (HRU) necessary
information. The manual also serves as a handbook for installation, maintenance and customer service
work. We recommend that any intervention in the appliance installation company should be consulted.
Subject of this operating manual is the control unit TAC4 with the operating unit GRC TAC4. Possible
accessories are only described insofar as it is necessary for the appropriate operation. Please see the
particular manuals for further information on accessories.
If you have any questions that have not been answered or have not been sufficiently answered in this
documentation, please contact the company Paul Wärmerückgewinnung GmbH. We will be glad to help
you.
1 Introduction
Safety 1.1
Please always observe the safety instructions in this operating manual. The non-observance of the safety
instructions, warning notices, notes and instructions can lead to injuries or damages to the maxi.
•Unless otherwise stated in this operating manual, only an authorised installer is entitled to install,
connect, put into operation and maintain the maxi;
•The installation of the maxi is to be performed according to the general local building, safety and
installation instructions of the corresponding local authorities, of the water works and electric
works and other official regulations and directives;
•Always follow the safety instructions, warning notices, notes and instructions described in this
operating manual;
•Please keep this manual during the complete life time of the maxi in proximity to the device;
•The instructions for the regular replacement of the filters or the cleaning of the supply and exhaust
air valves are to be strictly followed;
•The specifications stated in this document may not be changed;
•Any modification of the maxi is prohibited;
•In order to guarantee that the device will be regularly controlled, it is recommended to conclude a
maintenance contract. Your supplier can give you the addresses of authorised installers in your
area.
Used symbols 1.1.1
The following symbols are used in this manual:
Caution, special note!
Risk of: - injury of the user or the installer
- damages to the device
- impairment of the operation of the device if the instructions are not
carried out properly

4
2 Functionalities of the regulation
The TAC4 DG controller is mounted in the units of maxi-series.
This handbook describes the functionalities of the TAC4 DG when using a GRC TAC4 display. A
SAT MODBUS satellite (option) is used to connect the graphic remote control (GRC).
The TAC4 DG with GRC TAC4 controller provides the following features:
•Monitoring of the fans (exhaust and supply) in chosen working mode: constant airflow (CA),
constant pressure (CPs) or constant airflow linked to 0-10V signal (LS) (e.g. CO2 sensor).
•Management of 6 timeslots.
•Alarms on defects, set points, overpressure.
•Fire alarm airflow management.
•BOOST function, allowing to force a pre-set airflow (supply/exhaust), overriding the assigned
airflow
•Automatic management of the 100% bypass to allow free cooling.
•Automatic management of inlet dampers (CT).
•Heat exchanger antifreeze protection system by modulation of airflow or with an intelligent pre-
heat electrical coil (KWin).
•Post heating management of water coil (NV) or electrical coil (KWout) battery to keep a set
temperature constant.
The following options can be combined with TAC4 DG controller:
•SAT TAC4 BA/KW Option:
Regulation of 2 external heat exchangers (electrical/water, hot and/or cold).
•SAT TAC4 MODBUS Option:
MODBUS RTU communication (please refer to TAC4 DG - MODBUS RTU installation and user’s
manual for detailed information).

5
3 Generell maintenance instructions
Generell information 3.1
Generell schematic of the maxi-series 3.1.1
Maxi flat-series
Maxi-series
1 Main switch for power supply fans and control
2 Main switch for power supply to pre (Kwin) and/or post (Kwout) heating coils (options)
3 Centralized wiring box of the CB4 TAC4 DG circuit (factory pre-wired)
4 Supply fan(s)
5 Exhaust fan(s)
6 Post-heating water or electrical coil (NV or KWout option)
7 Motorized damper at fresh air inlet (CT option)
8 F7 class filter at fresh air inlet (G4- class filter extract air maxi flat right model versions)
9 Pre-heating electrical antifreeze coil (KWin option)
10 Drain pan and drain (maxi flat-series: drain pipe out)
11 Air/Air heat exchanger + bypass 100%
12 G4 filter on extract air (G4- or F7- class filter fresh air maxi flat right model versions)
13 Motorized damper at extract air inlet (option)
14 GRC TAC4
All electrical connections made the installer are in 1/2/3.
3

6
Schematic of the T° sensors positioning in the maxi unit 3.1.2
To allow easier identification of the temperature sensors 4 different wire colors are used:
-T1 : black wire
-T2 : white wire
-T3 : blue wire
-T4 & T5 : green wire (not at maxi flat-series)
Control panel 3 label located inside the cover 3.1.3

7
4 GRC wiring and funtionalites
The regulation is delivered fully factory pre-wired. Nevertheless, the TAC4 GRC (graphic remote control)
and the i/o signals if any must still be wired by the installer.
Installation of GRC 4.1
The GRC is designed for indoor use. For outdoor application, use a weatherproof
housing.
All the configuration data is enclosed in the TAC4 DG circuit. It is thus possible to
remove the GRC without disrupting the installation.
The GRC is delivered with attachments and fastening screws. Mounting panel thickness should not
exceed 5mm. The rectangular indent in mounting panel is 147x82mm.
Attachment mounting brackets Attachment on GRC

8
On wall installation 4.1.1
This kit GRC includes a box with an opening in the lid where the GRC touchscreen fits perfectly.
Fix the GRC in the lid with the mounting brackets supplied in the GRC kit GRC.
The cable entry holes in the box will have to be done by the installer.
In wall installation 4.1.2
This kit GRC allows the touchscreen GRC to be flush mounted in a wall. It includes a box and a stainless
steel front panel on which the GRC can be fixed.
220
85 170
4 fixations
130
180

9
Fix the GRC in the stainless steel panel with the mounting brackets supplied in the GRC kit.
The cable entry holes in the box will have to be done by the installer.
Wiring of GCR TAC4 4.2
Follow these steps to connect the GRC TAC4 to the CB4 TAC4 DG:
Plug SAT MODBUS satellite on CB4 TAC4 DG 4.2.1
First, make sure the power is shut down, then plug the SAT MODBUS on the CB4 TAC4 DG circuit
connector (see picture).
Warning: plugging the SAT in the wrong connector can be fatal to both circuits !
205
175
150
120

10
Wiring diagram to connect the GRC TAC4 REC to the SAT MODBUS 4.2.2
4.2.2.1 Cable specifications
•Recommended cable: category 5 shielded twisted pair (FTP) cable with a section of 0,26 … 0,50 mm².
Use 1 pair to connect GND and +12V and 1 pair to connect B- and A +.
•Maximum cable length: 1000 m.
•Keep this communication cable at distance from power cables..
•If the unit is installed in a location with high electro-mechanical interference levels we strongly advise
to connect the armored shield of the TAC4 DG – GRC cable on one side of the ground only.
•If the maxi-series is installed outside, select a suitable cable for outdoor application (UV light, …).
4.2.2.2 Wiring several circuits on one GRC
•The maximum number of circuits that can be connected on one GRC is 247 units (manual monitoring).
•The "network" screen can only monitor 5 units at a time (automatic monitoring).
•Wire specifications between 2 SAT MODBUS: shielded twisted pair (FTP), category 5, Section of
0.26... 0,50 mm². Use same pair to connect B - and A +. The circuits shall be connected in series as
shown on the wiring diagram below.
Wiring diagram
A + = black wire
B - = brown wire
GND = metal wire

11
Power GRC TAC4 4.2.3
Use a 24 Vdc power supply. Maximum power consumption is 5W. The TAC4 DG provides a 24Vdc output
for this purpose. See wiring diagram below.
Same wiring is applied in case an NV option is used (3 way valve power supply). Be
extra careful to wire ‘properly’, as improper wiring can cause malfunctioning of the
installation.
Selecting the master 4.3
«Selecting the master» means the determination of which module of the i/o and the RC will “control” the
fans, “controlling” the fans means:
- If CA mode is chosen (§ 5.2.1), to be the master means to control the start/stop of the fans as well as to
select the airflow
- If LS or CPs mode (§ 5.2.2 and 5.2.3), to be the master means to control the start/stop of the fans as
well as to activate/deactivate a different assignment (assignment multiplier).
2 setups are possible:
1) Or TAC4 DG circuit is «master»: contact between terminals IN1 and +12Vdc of TAC4 DG circuit is
closed.
- The TAC4 DG circuit allows control of the fans through its inputs.
- The GRC TAC4 allows to configure and to clearly visualize all the parameters,
2) Or GRC TAC4 is « master »: contact between terminals IN1 and +12Vdc of TAC4 DG circuit is open.
- The TAC4 DG circuit is then in control of the system and serves as a control hub between fans and the
GRC TAC4.
- The GRC TAC4 allows to configure and to visualize all the parameters on the display screens,
- The GRC TAC4 controls the fans
TAC4 DG circuit is master
Control Visualization
GRC TAC4 is master
Control
Visualization
A + = black wire
B - = brown wire
GND = metal wire
+ = Vo
- = GND

12
Wiring diagram
Contact closed = TAC4 DG circuit master
Contact open = GRC TAC4 master
Caution: Use gold-plated contact only.
The use of this contact enables to switch automatically from GRC TAC4 master to TAC4 DG master.
Using this you can for instance:
•Work in GRC TAC4 master and switch in position TAC4 DG master to stop automatically the
fans (attention, in this case the inputs K1/K2/K3 on the TAC4 DG have to be disconnected from
the +12V).
•Work in GRC TAC4 master and switch in position TAC4 DG master to activate automatically a
sleep value (attention K1/K2/K3 on the TAC4 DG have to be properly connected to activate this
value).
Fan control 4.4
The various working modes give the user the choice on how the airflow must be modulated according to
your application.
In all the working modes the supply fan will operate according to the assigned mode and parameters.
The airflow of the exhaust fan will then equal to a percentage of the actual airflow of the supply fan (noted
%EXT / PUL for ratio between exhaust and supply airflows).
The GRC TAC4 allows configuration of one of the following 4 modes:
•CA MODE:
3 constant airflow assignments for the supply fan are determined by the user (m³h K1, m³h K2 and
m³h K3).
•LS MODE:
The assigned supply airflow is a function of a 0-10V linear signal. The user defines the link with 4
parameters: Vmin, Vmax, m³h≡Vmin and m³h≡Vmax, applied to the following diagram:
With m³h≡Vmin < or > m³h≡Vmax (positive or negative link).
Using the advanced setup, it is possible to stop the fans once the
input signal value has reached a certain upper and/or lower limit.
•CPs MODE:

13
CPs on supply: the airflow of the supply fan(s) is modulated so as to maintain constant a certain
pressure value measured by a pressure sensor properly located in the ducting.
CPs on exhaust: the airflow of the exhaust fan(s) is modulated so as to maintain constant a certain
pressure value measured by a pressure sensor properly located in the ducting.
•MODE OFF:
Is not a real working mode, it is a way to temporarily shortcut the TAC4 DG master setup. It allows, if
working in TAC4 DG master, to stop the fans with the GRC TAC4. But then to restart the fans it is
required to choose one of the other 3 working modes.
Time slots schedules 4.5
Definition 4.5.1
The TAC4 DG regulation allows to configure up to 6 time slots per day.
For each time slot select:
•The exhaust and the supply airflows:
oWorking mode (CA, LS, CPs or OFF)
oCA mode: select the actual exhaust and supply airflow
oLS mode : select a % value of the link configured as well as a %age value of the
unbalance between exhaust and supply airflows (% exhaust/supply)
oCPs mode : select a %age value of the reference pressure as well as a %age value of
the unbalance between exhaust and supply airflows (% exhaust/supply)
•Bypass status: choose either automatic (see § 4.7) or either «force» the bypass to «open» or
«close» for the TSiconsidered.
•If post heating installed (option): set the assignment t° for the supply air for the TSiconsidered
•If post-cooling installed (option) set the assignment t° for the supply air for the TSiconsidered
Seasonal management is also possible :
•Force bypass ‘close’ between 2 dates (avoid free cooling in the winter)
•Disable the post-heating feature between 2 dates (avoid post heating in the summer)
•Disable the post-cooling feature between 2 dates (avoid cooling in the winter)
Alarms 4.6
Alarm types 4.6.1
The TAC4 DG features 14 alarms types divided in 9 categories (alarms table in § 4.5.2 ).
Type 1: Alarm indicating a fan failure (1).
This alarm indicates a failure of fan Fx. Main cause for this alarm is power supply to the motor or the
motor itself. Check also the wiring and fan connections to TAC4 DG circuit.
See 1 in table 4.5.2 below.
Type 2: Alarm on the pressure variation (CA and LS modes only).
This alarm indicates a pre-established pressure level has been reached on fan Fx.
Pressure alarm setup in CA or LS mode (see § 5.2.1.1 and 5.2.2.1).
See 2 in table below.
Type 3: Alarm indicating a problem while initializing reference pressure for a pressure alarm (1).
4 possibilities:
•Actual airflow < requested airflow : The requested working point is ‘too high’ (too much pressure) for the
maximal available pressure at the requested airflow for this fan.
•Actual airflow > requested airflow: the nominal airflow requested to initialize the pressure alarm cannot
be reached because the lower limit of the fan’s operating zone has been reached.
•Very unstable pressure (pumping).
•Assigned airflow not reached after 3 minutes.
See 3 in table below.

14
Paréf cannot be identified and the fans are stopped.
Press « ALARMS RESET» in «Alarms» tab of the «Visualization» menu, or with the ‘RESET’ key on the
TAC4 DG circuit.
- If it occurs during initializing an alarm pressure 2 options: 1. No action is taken: the control will operate
without pressure alarm 2. Corrective action is taken (change the working point to one well located in the
working zone of the fan, by reducing the pressure system, modifying the nominal airflow,… ) and restart
the setup operation.
- If it occurs during initializing of the assignment pressure in CPs mode : A corrective action must be taken
(change the working point to one well located in the working zone of the fan, by reducing the pressure
system, modifying the nominal airflow, …) and restart the setup operation.
Type 4: Alarm indicating the system cannot fulfill the assignment (1).
The assignment (keeping certain airflow or a certain pressure constant) cannot be fulfilled because the
upper or lower limit of the fan’s working zone has been reached.
See 4 in table below.
Type 5: Alarm indicating a data failure in the control circuit.
Crucial data from the circuit board has been lost. Try a TOTAL RESET using the «Admin» tab in the
«Advanced Setup» menu.
If still not solved send the defect TAC4 DG circuit for reprogramming.
See 5 in table below.
Type 6: Fire Alarm with an external contact connected to a fire detection system.
See 6in table below. For more details, see § 4.5.4.
After a fire alarm it is necessary to perform a RESET (use «ALARMS RESET» in the «Alarms» tab of the
«Visualization» menu or the RESET button on the TAC4 DG circuit to return to normal operation).
Type 7: Alarm indicating maintenance is expected. (for configuration see “advanced setup):
SERVICE ALARM: indicates the fan operating time (in hours) has exceeded a certain limit set during the
configuration.
STOP FAN: indicates the fan operating time (in hours) has exceeded a certain limit set during the
configuration.
This alarm stops the fans.
See 7 in table below.
Type 8: Not applicable with GRC TAC4.
Type 9: Alarm indicating a T° sensor T1/T2/T3 failure.
One or more of the T° sensors T1/T2/T3 connected to the TAC4 DG circuit and mounted on heat
exchanger is defect or not connected. These sensors are crucial for the by-pass control and the antifrost
procedure.
After correction of the failure, reset using «ALARMS RESET» in the «Alarms» tab of the «Visualization»
menu or the RESET button on the TAC4 DG circuit to return to normal operation.
See 9 in table below.
Type 10: Alarm indicating failure on T° sensor T4 (only with NV option).
It indicates that the T° sensor T4 located on the coil and connected to the TAC4 DG circuit is defect (open
or short circuit) or not connected. This sensor is used to avoid frosting of the NV coil. In this case, as a
safety measure, the 3 way valve is opened and the contact used to start the circulator is closed.
After fixing the failure, reset using «ALARMS RESET» in the «Alarms» tab of the «Visualization» menu, or
press RESET on the TAC4 DG circuit.
See 10 in table below.
Type 11: Alarm indicating failure on T° sensor T5 (only with NV option or KWout).
It indicates a failure of the T° sensor T5 located in the supply duct and connected to the TAC4 DG circuit
(opened or short circuit) or that it is not connected. This sensor is used to regulate the post-heating
function.

15
After fixing the failure, reset using «ALARMS RESET» in the «Alarms» tab of the «Visualization» menu or
press RESET on the TAC4 DG circuit.
See 11 in table below.
Type 12: Alarm indicating that the assigned T° cannot be reached (only with NV option or KWout).
If the actual T° is lower than the assigned T° for more than 15 minutes with the post-heating fully opened
until)
See 12 in table below.
Type 13 et 14: Alarm indicating antifrosting alert (only with KWin option).
In certain air T° conditions as measured on the exhaust airflow after the heat recovery, indicating that the
Kwin has reached its limit, the TAC4 DG control can take over to guarantee the antifrost function.
a) Alarm type 13: If T° < assignment T°-1,5°C for more than 5 minutes: supply and exhaust airflow
reduction of 33% if CA or LS and of 25% if CPs, for 15 minutes.
b) Alarm type 14: If T° < -5°C during 5 minutes, fans are stopped. Reset using «ALARMS RESET» in the
«Alarms» tab of the «Visualization» menu, or press RESET on the TAC4 DG circuit to restart the unit.
See 13 & 14 in table below.
Alarm table 4.6.2
Actions on GRC
TAC4
A
ctions on the TAC4 DG circuit Action on
fans
Category Type LED
Alarm LED Pa
A
L1 relay R2 relay
of SAT3
(O.R.1)
LED AF
Fans 1
Red / Alarm status / / Stopped
Pressure 2 / Red / Closed / /
(1)
Init Pa 3 Red / Alarm status / / Stopped
Set point 4 Red / / / / /
Software 5 Red / Alarm status / / Stopped
Fire alarm 6 Red / Alarm status / / Stopped
(2)
Maintenance 7 a)
7 b)
Red
Red
/
/
Alarm status
Alarm status
/
/
/
/
/
Stopped
/
8 / / / / / /
T° sensors 9 Red / Alarm status / / Stopped
T° sensors 10 Red / Alarm status / / /
T° sensors 11 Red / Alarm status / / /
Set point 12 Red / / / / /
Anti freeze 13 Red / / / ON Reduced
Anti freeze 14 Red / Alarm status / Blinking Stopped
/ = no action
(1) Unless the status has been changed in advanced setup to stop the fans.
(2) See details in § 4.5.4.

16
Wiring diagrams 4.6.3
Fire alarm 4.6.4
The TAC4 DG control can be connected to a fire detection system to:
- stop/start the supply/exhaust fans according to fire regulations
- set the airflows in case of fire alarms according to fire regulations
- allow firemen to overrule the existing setup and start/stop the fans as needed.
4.6.4.1 Configuration
The supply / exhaust airflow configuration is made using the advanced setup
Full details: see the advanced setup in documentation.
4.6.4.2 Wiring diagram of fire alarm
If IN3 12V closed = fire alarm activated (this logic can be reversed via advanced setup menu).
Default, if IN3 – 12 V closed and :
•IN7 - 12V closed = force start the supply fan(s) at pre-programmed airflow (1).
•IN7 - 12V open = force stop the supply fan(s).
•IN8 - 12V closed = force start the exhaust fan(s) at pre-programmed airflow (1).
•IN8 – 12V open = force stop the exhaust fan(s).
(1) At preset airflow in the advanced setup menu
O.R.1 O.R.2

17
BOOST function 4.7
The BOOST function allows forcing a preset airflow overruling all other configurations..
Setup 4.7.1
The configuration is made via the advanced setup.
Wiring diagram 4.7.2
BYPASS function (free cooling) 4.8
The counter flow heat exchanger is fitted with a 100% bypass. When the bypass is open fans may:
- Either continue to operate the same way as when the bypass is closed.
- Either operate at a fixed exhaust and supply airflow rate. These airflow values can be (re)set via the SETUP
AVANCE.
According to inside and outside temperatures, the TAC4 DG control will monitor the opening/closing of
the 100% by-pass damper. The by-pass is delivered completely wired and motorized from factory. No
wiring or installation is required by the installer. The O.R.4 relay (SAT3 option) of the TAC4 DG circuit
indicates the opening / closing of the bypass.
Operating description:
•Die Opening of 100% bypass if all following conditions are met:
oOutside T° (sensor T1) < inside T° (sensor T2) – 1K.
oOutside T° (sensor T1) > 15°C
oInside T° (sensor T2) > 22°C.
•Closing of 100% bypass if one of the following conditions is met:
oOutside T° (sensor T1) > inside T° (sensor T2).
oOutside T° (sensor T1) < 14°C
oInside T° (sensor T2) < 20°C.
All these temperature SET values can be modified using ADVANCED SETUP
Contact open: BOOST inactive
Contact closed: BOOST active

18
Opening of the bypass can be forced whatever the T° (with an external contact):
(*) When the bypass is open, the pressure alarm is deactivated. For the maxi 4002 and maxi 6002 models
the maximum airflow when the bypass is open is reduced respectively at 3500 m³/h and 5300 m³/h. For
the other models, there is no reduction of the maximum airflow when the bypass is open.
Opening / closing of dampers (CT option) at inlet 4.9
The opening and closing of (a) damper(s) mounted at both supply and exhaust air inlets are automatically
managed by the TAC4 DG regulation.
The actual fan startup is delayed to allow prior opening of dampers. When fans are stopped the dampers
are closed.
Heat exchanger antifrost protection system 4.10
There is a risk of frosting the heat exchanger in the exhaust airflow. Two antifrost protection systems are
available:
•Supply air volume reduction (less cooling capacity)
•Modulation of capacity of an electrical coil located before the inlet air enters the heat exchanger
(KWin option)
Protection antifreeze via pulse flow reduction 4.10.1
This functionality is built in the standard TAC4 DG and must not be configured by the installer. It is automatically
de-activated if an optional KWin pre-heater (see § 4.9.2) is installed in the unit.
Description:
In order to avoid the risk of frosting the heat exchanger, the supply airflow is linked to the temperature value of
the exhaust airflow measured after the heat exchanger (sensor T3).
•T°(T3) > +3°C: the assigned airflow is as defined by SETUP.
•0°C < T°(T3) < +3°C : the airflow assigned by SETUP is automatically modified as follows:
- If CA or LS working mode : the supply airflow will progressively drop down to 33% (AFlow) of the assigned
airflow (AFn)
- If CPs mode, the assigned pressure will drop to 50% (AFlow) of the assigned pressure (AFn)
In these conditions LED AF is ON. The "antifrost" led on the "Synoptic" screen ("Visualization" menu of
GRC TAC4) is ‘on’ and an explanatory text appears in the "flow" tab.
•T°(T3) < 0°C : the supply airflow is stopped for as long as T°(T3) < +1°C during 5 minutes. In these
conditions LED AF is blinking. The "antifrost" led on the "Synoptic" screen ("Visualization" menu of
GRC TAC4) is ‘on’ and an explanatory text appears in the "flow" tab.
All these temperature SET values can be modified using ADVANCED SETUP.
Antifreeze diagram:
Contact open: automatic bypass operation in function of T1,
T2 and setup values.
Contact closed: bypass is open whatever T1 and T2 values