28
6.3 INSTRUMENTATION AND CONTROL (I&C) SYSTEM
The standard part of the unit is its own control system. The design of the unit is ready for cooperation with the Digireg
®
digital controller.
6.3.1
DIGITAL REGULATION SYSTEM DIGIREG
®
The control system is located in a compact sheet steel switchboard equipped with a main switch, digital controller on the PCB board and safety
and switching elements for individual HVAC units. The cables pass through plastic bushings with locking in the left side of the cabinet.
Basic dimensions of Digireg
®
M3-Vx switchboard with protection level IP20:
The switchboards M1-E2 to M3-E36 have dimensions 660 x 660 x 120 mm.
The Digireg
®
switchboard with IP65 protection has dimensions of 640 x 600 x 210 mm.
6.3.2 TEMPERATURE REGULATION
The Digireg
®
controller is designed to control the output of the heater or cooler of the air handling unit to reach the desired temperature. Digireg
®
can command direct cooling or a heat pump. There is a 3-point output for servo drive of the mixing valve, direct power outputs SSR for electric
heating or two analogue outputs 0
–10 V / 0–20 mA. The heat pump or cooling unit is controlled by potential-free contacts.
–
Regulation to a constant supply air temperature
uses one temperature sensor in the supply pipe, the supply air is heated or cooled to the required set temperature within the minimum and
maximum configured temperature
Regulation to a constant temperature of the exhaust air
uses one temperature sensor in the exhaust pipe, the supplied air is heated or cooled to the required set temperature within the minimum
and maximum configured temperature
Spatial temperature control (for constant room temperature)
cascade control is used with limitation of the minimum and maximum supply air temperature. The main sensor is placed in a ventilated
area, the supply air sensor is placed in the outlet of the unit in a place with sufficient air mixing. If the room temperature is higher than the
set value, the controller will try to reduce the supply air temperature to the set minimum supply air temperature. If the room temperature
falls below the set value, the controller tries to compensate for this by increasing the supply air temperature. The room temperature can be
selected as the room temperature, the temperature from the sensor in the controller, or from a separate sensor connected
to the motherboard. The controller cools or heats according to the set parameters in the automatic summer/winter mode according to the
outdoor temperature
and time dependencies.
Manual mode selection is also possible. The heater can be hot water, controlled by a three-
point actuator, or electric, directly controlled by SSR, or external TRIAC switches 0-10 V. Electric heater controlled by internal SSR can
have up to 36 kW depending on the cabinet, water heater is not limited mixing unit size). Cooling can be cold water, controlled by a 0-10 V
analogue actuator or direct in conjunction with a condensing cooling unit.
–
–
6.3.3
INSTALLATION
IP20 protection controllers are designed for installation in an indoor dry environment without aggressive chemicals in normal areas according
to ČSN 33 2000-3, ambient temperature up to 30 °C. The short-circuit resistance of the Digireg
®
switchboard is 6 kA.
Distribution board
protection is IP20 or IP65 and the material is listed
below in the catalog sheets at www.solerpalau.co.uk
.
Cross-sections of power cables (fans,
pumps, electric heaters…) must be designed according to specific installation conditions in accordance with
ČSN 33 2000-5-52 ed.2.
The installation must be carried out by an authorized person working on electrical equipment in accordance with legal requirements and familiar
with the function
of the individual components of air conditioning and control. Observe the valid ČSN during installation.
An initial inspection
must be performed before commissioning.
For the assembly and installation of air conditioning, an authorized project of air conditioning and
M&R is required, which solves both the air outputs and the piping system, as well as the electrical connection of elements and operating
modes.
!
For heat recovery units supplied with a free located Digireg
®
control box, which is not fixed to
the unit wall, the firm housing must be ensured of harness between the unit and control box in
the firm cable line (such as cable trays, cable bench etc.). The harness between the unit and
the control box shall not be freely suspended or positioned on the floor!!! After firm laying of the
harness it is possible to start the works on connection of individual wires to the Digireg
®
control box.
!
CAUTION!
Digireg
®
distribution boards are not
designed for direct installation to the
flammable material!
!
CAUTION!
For units with a direct evaporator (marked DX and DXr in the unit
code), it is possible to maintain the required air temperature in
the room with accuracy, depending on the correctness of the
project and the correct function and setting of the ventilation
system with accuracy of ±2°C.