2.2 Description of internal components
2.2.1 Supply and Extract air Fans
The fans have external rotor motors of EC type which are steplessly controlled individually by setting the
control signal to a fixed value. It is possible to program the speed in 2 steps (normal/reduced) depending
on the programming of the week schedule. The motor bearings are life time lubricated and maintenance
free. It is possible to remove the fans for cleaning, see chapter 5 for more information.
2.2.2 Supply and Extract air Filters
The filters are of bag filter type with filter quality F7 for the supply air filter and M5 for the extract air filter.
The filters need to be replaced when polluted. New filters can be acquired from your installer or wholesaler.
2.2.2.1 Pressure guard for filters
A pressure guard measures the differential pressure over the supply and extract air filters (pos. 9figure 1.
When the pressure drop reaches the set value an alarm is triggered in the main regulator. The differential
pressure can be set between 40 and 300 Pa. The pressure switch is preset from factory to 240 Pa.
2.2.3 Heat Exchanger
Topvex FC models are equipped with a counter flow heat exchanger and a by-pass damper. The operation
of the by-pass damper is automatic and depends on the set temperature or if deicing is in operation.
The heat exchanger is removable for cleaning and maintenance, see chapter 5 for more information.
2.2.4 Temperature sensor
4 temperature sensors (PT1000) are included in the unit from factory. The sensors are as follows:
• Supply air sensor
• Extract air temperature sensor
• Outdoor air temperature sensor
• Efficiency temperature sensor
In Topvex FC all temperature sensors are mounted and wired inside the unit except for the supply air
sensor, which is loosely delivered with the unit and needs to be installed in the supply air duct externally
from the unit. See Installation instructions for more information.
2.2.5 Water heating battery
In units with built in water heating battery the hot water coil is located next to the supply air connection.
The hot water coil can be either HWL (hot water coil, low power) or HWH (hot water coil, high power).
The coil material is copper piping with a frame of galvanized sheet steel and aluminium fins. The coil is
equipped with venting and immersion sensor for frost protection.
2.2.6 Electrical Heater
In units with built in electrical heater the heating rods are located after the supply air fan in the airflow
direction. The material is stainless steel. The electrical heating battery has both automatic and manual
overheating protection. The manual overheat protection is reset by pushing the red button on top of the
electrical heater frame (pos. 11 figure 1). The power demand of the electric heating coil is controlled by the
main regulator, which controls the heat steplessly by a TTC triac control according to the selected control
function that is set in the control panel.
Topvex FC
Operation and Maintenance Instructions
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Systemair Sverige AB
