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3 - HARDWARE DESCRIPTION
3.1 - Control boards
Each circuit is by default fitted with one SIOB board used
to manage all inputs and outputs of the controller. At the
same time, Energy Management Module (EMM) requires
an additional SIOB board to be installed. The control also
includes up to four AUX1 boards used to control refrigerant
leak detection option, master/slave assembly control, and
internal or external pumps' control.
All boards communicate via an internal LEN bus.
Touch Pilot continuously monitors the information received
from various pressure and temperature probes and
accordingly starts the program that controls the unit.
The unit is equipped with the Touch Pilot user interface
(7- inch colour LCD touch screen).
The electrical box includes all boards controlling the unit
and the user interface.
3.2 - Power supply to boards
All boards are supplied from a common 24 VAC supply
referred to earth.
In the event of a power supply interrupt, the unit restarts
automatically without the need for an external command.
However, any faults active when the supply is interrupted
are saved and may in certain cases prevent the unit from
restarting.
CAUTION: Maintain correct polarity when connecting the
power supply to the boards, otherwise the boards may be
damaged.
3.3 - Light emitting diodes on boards
All boards continuously check and indicate the proper
operation of their electronic circuits. A light emitting diode
(LED) lights on each board when it is operating properly.
• The red LED flashing for a two-second period on the
SIOB board indicates correct operation. A different
rate indicates a board or a software failure.
• The green LED flashes continuously on all boards to
show that the board is communicating correctly over its
internal bus. If the green LED is not flashing, this
indicates a LEN bus wiring problem.
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3.4 - Connections of the main controller
Connections are located on the bottom side of the main
controller.
The controller comes with two RS485 ports, where the first
port is used to connect to CCN (Carrier Comfort Network)
and the second RS485 port is used for internal communication
(LEN). The Ethernet port allows for TCP/IP communication
or BMS (Building Management System) connection thanks
to BACnet/IP communication.
Legend:
1.
USB connector
2.
Ethernet connector
3.
CCN connector (RS485)
4.
LEN internal bus (RS485)
5.
Power supply connector (24 VAC)
3.5 - Pressure transducers
Two types of electronic sensors (high and low pressure) are
used to measure various pressures in each circuit.
These electronic sensors deliver 0 to 5 VDC. The sensors
are connected to the slave boards.
Suction pressure sensors (low pressure type)
These sensors measure the suction pressure in each circuit.
They are used for EXV control. Suction pressure sensors are
located on the suction piping of each circuit.
Discharge pressure sensors (high pressure type)
These sensors measure the discharge pressure in each circuit.
They are used to control head pressure or high pressure load
shedding. Discharge pressure sensors are mounted on the
discharge line piping of each circuit.
Oil pressure sensors (high pressure type)
These sensors measure the oil pressure of each compressor.
Oil pressure sensors are located at the oil port of the
compressor. The economizer pressure is subtracted from this
value to arrive at the differential oil pressure.
Economizer pressure sensors (high pressure type)
These sensors measure the intermediate pressure between
discharge and suction pressure. They are used to control the
economizer performance.
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