Paul BUS User manual

Status: 06.11
BUS thermostatBUS thermostat
Paul Wärmerückgewinnung GmbH
August-Horch-Straße 7
08141 Reinsdorf
Tel.: +49(0)375 - 303505 - 0
Fax: +49(0)375 - 303505 - 55
Germany
Operating InstructionsOperating Instructions
Please keep next to the MVHR unit! Please keep next to the MVHR unit!

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Table of Contents
0Introduction............................................................................................................................ 2
1Brief product description ...................................................................................................... 2
2Installation.............................................................................................................................. 2
2.1Electrical connections .............................................................................................................. 2
3Operating modes.................................................................................................................... 4
3.1Frost protection operating mode............................................................................................... 5
3.1.1Electric frost protection heater.................................................................................................. 5
3.1.1.1Electric frost protection heater with PTC heating element........................................................ 5
3.1.1.2Electric frost protection heater with resistance heating element............................................... 6
3.1.2Brine-defroster ......................................................................................................................... 7
3.2Supply heater operating mode ................................................................................................. 7
3.2.1Electric heater battery .............................................................................................................. 7
3.2.2Water supply heater................................................................................................................. 8
3.3Ground pipe diverter (Valve for ground heat exchanger - ground pipe diverter valve).............. 9
Appendices:
Appendix 1: Wiring diagram BUS thermostat
Appendix 2: Technical data BUS thermostat

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0 Introduction
READ THESE INSTRUCTIONS CAREFULLY BEFORE INSTALLING AND USING THE EQUIPMENT!
THIS INSTRUCTION HAS BEEN MADE WITH THE GREATEST CARE.
HOWEVER, THIS INSTRUCTION CONFERS NO RIGHTS. WE RESERVE THE RIGHT TO CHANGE
ALL OR PART OF THE CONTENTS OF THIS INSTRUCTION WITHOUT PRIOR NOTICE.
This instruction contains all information necessary for an optimal installation and startup by skilled
personnel. It can also be used as a manual for maintenance and service work.
It is absolutely important to follow the instructions in this manual very thoroughly in order to guarantee the
correct function of the unit. Not following the instructions in this manual and/or using non-original parts
lead to a lapse of any warranty and liability claims.
Please contact Paul Wärmerückgewinnung GmbH for further assistance if there are any questions left
which are not covered in this manual.
The following symbols are used in this manual:
Attention, special note!
Risk of: - physical injury of user or installer
- damaging the unit
- failures if the instructions are not followed thoroughly
1 Brief product description
The BUS thermostat is used as control unit of the universal control for the components frost protection,
supply heater battery and ground pipe diverter valve. In connection with the necessary sensors, e.g.
temperature sensor, flow sensor and room thermostat or motor/proportional valve, this module controls
the necessary parameters for a save, comfortable and energy efficient operation of the ventilation system.
The central communication control / monitoring including the 24 VDC power supply of the controller is
realized via the RS485 BUS. The BUS thermostat is equipped with a pulse packet controlled or direct
power output.
2 Installation
The BUS thermostat shall be installed max. 2 m away from the device it controls. The housing is surface-
mounted using 4 screws.
A 230 VAC power supply has to be provided next to the BUS thermostat. The BUS thermostat has
protection class IP 20.
2.1 Electrical connections
The electrical connections of the BUS thermostat have to be executed by
professionals according to DIN-VDE standards part 1!
The BUS thermostat's mains cable with safety plug has to be connected to the 230 VAC mains socket.
The control cable is led through a cable gland and, according to the type of device, connected to the
terminals 7 to 11 of the terminal strip X1. The sensor and actuator cables are led through a cable gland
and connected to the corresponding terminals of the terminal strip X1 or terminal strip X2.
A CAT 5 network cable connects the RJ45 female connector of the BUS thermostat with the RJ45 female
connector of the adapter board (if only one component is installed) or with the RJ45 female connector of a
Y-board (Extension for connection of 2 components). Figure 1 shows the basic arrangement for
communication of the internal RS485 BUS is shown.

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Figure 1: Basic arrangement connecting BUS thermostat
The RJ45 plug-in connection of the BUS thermostat, the adapter board and the Y-
bord are for communication purposes with the internal RS485 BUS only! Every
other use results in damaging the internal modules!
All electrical connections of the BUS thermostat board are described in appendix 1 wiring diagram BUS
thermostat.

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Figure 2: Overview BUS thermostat
3 Operating modes
The operating mode for the respective modules is configured using the DIP switch S2. The combination
of the switch settings S2.1 and S.2.2 of the DIP switch S2 defines the possible functions of the modules
controlled by the BUS thermostat. The basic operating mode on the bus has to be unique.
Using the BUS thermostat as control unit of the universal control realizes the following functions:
Frost protection
- Electric defroster heater
- Brine-defroster
Supply heater
- Electric heater battery
- Water supply heater
Ground pipe diverter (Valve for ground heat exchanger - ground pipe diverter valve)
- freely configurable temperature conditions for opening and closing the ground pipe diverter valve
The BUS thermostat parameters are set using the TFT touch panel control unit. All
settings (enablings, temperature threshold, etc.) are conducted via the menu (Settings
/ Setup) and transmitted via the RS485 BUS. The temperature sensort NTC has to be
connected to X2 for temperature threshold monitoring!
Cable
connection
power supply
Holes for
fixation with
screws
RJ45
female
connector
Cable gland for sensor / actuators Terminal X2
1 analog input for sensor / 1 analog output for actuator
Holes for
fixation with
screws
Terminal X1
Module connection / 2 digital inputs for actuators
Cable
connection
module

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Figure 3: Functions of switch settings S2.1 and S2.2 of the DIP switch S2
3.1 Frost protection operating mode
3.1.1 Electric frost protection heater
The electric frost protection heater has to be integrated in the intake air duct of the ventilation unit. The
temperature sensor NTC has to be installed in the intake air duct downstream the electric frost
protection heater and upstream the intake air connection of the ventilation unit. The electric frost
protection heater heats up the intake air which is led into the heat exchanger, so the temperatures do not
fall below frost protection thresholds and the heat exchanger is able to continue operation without
freezing.
The electric frost protection heater is supplied with pulse packet controlled power via output L1.
Maximum switching capacity 2 kW!
3.1.1.1 Electric frost protection heater with PTC heating element
The electric frost protection heater with PTC heating element does not need a digital flow indicator STR.
The combination of switch settings of the DIP switch S2, the terminal configuration X1 and X2 for control
of the electric frost protection heater with PTC heating element is shown in figure 4.

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Figure 4: Configuration of electric frost protection heater with PTC heating element
3.1.1.2 Electric frost protection heater with resistance heating element
The electric frost protection heater with resistance heating element has to be run with a digital flow
indicator STR. The digital flow indicator is either part of the module or has to be installed separately in the
intake air duct with a straight flow distance of 5 x DN.
The electric frost protection heater with resistance heating element is only
activated if the enabling contact STR is closed, so that the flow indicator detects an
air flow through the electric frost protection heater!
The combination of switch settings of the DIP switch S2, the terminal configuration X1 and X2 for control
of the electric defroster heater with resistance heating element is shown in figure 5.

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Figure 5: Configuration of electric frost protection heater with resistance heating element
3.1.2 Brine-defroster
The brine-defroster has to be integrated in the intake air duct of the ventilation unit. The temperature
sensor NTC has to be installed in the intake air duct upstream the brine-defroster. A brine-pump is
actuated if a brine-defroster is used. L1 does not issue any pulse packets, but switches the pump on or
off. The temperature conditions are the same as temperature conditions of the electric defroster.
Additionally, a cooling function can be activated for the brine-defroster module (ref. to menu settings/brine
loop cooling). The cooling function cools the air led to the heat exchanger once a predefined temperature
threshold is exceeded.
The combination of switch settings of the DIP switch S2, the terminal configuration X1 and X2 for control
of the brine-defroster pump is shown in figure 6.
Figure 6: Brine-defroster configuration
3.2 Supply heater operating mode
3.2.1 Electric heater battery
The electric heater battery has to be installed in the supply air duct of the ventilation unit. The
temperature sensor NTC is installed. The room temperature can be controlled by connecting a room
thermostat RTH for set-point assignment downstream the electric heater battery. This room thermostat
is generally for enabling the supply heater. The pulse packet length control of the electric heater battery is
identical to the pulse packet length control of the electric frost protection heater, except that it is set to a
predefined duct temperature (ref. to menu setup/Post-heating).
Duct temperature control is realized by comparing the actual value of the NTC temperature sensor with
the duct temperature's set-point assignment, the backup duct heater is controlled power modulating
according to the variance.
Maximum switching capacity 2 kW!
The electric heater battery with PTC heating element does not need a digital flow
indicator STR. In this case, a ju,per has to be set between terminal 3 and terminal 4
on terminal strip 1.

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The electric heater battery with resistance heating element has to be run with a digital flow indicator STR.
The digital flow indicator is either part of the module or has to be installed separately in the supply air duct
with a straight flow distance of 5 x DN.
The combination of switch settings of the DIP switch S2, the terminal configuration X1 and X2 for control
of the electric heater battery is shown in figure 7.
Figure 7: Electric heater battery configuration
3.2.2 Water supply heater
The water supply heater has to be installed in the supply air duct of the ventilation unit. The temperature
sensor NTC is installed in the supply air duct downstream the water supply heater. The room
temperature can be controlled by connecting a room thermostat RTH for set-point assignment. This room
thermostat is generally for enabling the supply heater.
If using a water supply heater, a pump is switched on or off via L1. The pump is switched on if RTH is
closed via the room thermostat. The duct temperature, measured by NTC, results of the water
temperature. Therefore, the duct temperature is not controlled via L1.
In addition to the system's frost protection, a frost protection is implemented to protect the water pump. In
case the temperature of the NTC falls below 5°C, the pump is switched off.
Optionally, a proportional valve (motor valve) can be connected to the analog 0-10 V output. The valve
regulates the amount of hot water mixed with the cold water, so the result is the predefined duct
temperature. If the temperature measured rises above the duct temperature, the voltage on the 0-10 V
output is lowered more and more. If the temperature falls below the duct temperature, the voltage is
increased again. The voltage is kept constant within the hysteresis of 1 K around the duct temperature.
The control system has a pi-characteristic and a time constant of 2,5 s. If the temperature measured is,
for example, is 10 k smaller than the duct temperature, the voltage at 0-10 V output is increased from 4 V
to 10 V within 15 s.
The input STR is not evaluated.
The combination of switch settings of the DIP switch S2, the terminal configuration X1 and X2 for control
of the water supply heater is shown in figure 8.