EC converter with air quality sensor input
New electronics: takes over the EC-SWAP function and adds air quality control. The sensor, sold separately, connects directly to the module and varies the EC motor setpoint between LOW and HIGH. The two modules of a dual-flow air handling unit are linked: supply and extract vary together.
Available in 2027. Announced: specifications being published. Availability and lead time confirmed in the quotation. For sizing, call +41 27 326 60 00.
How it works
With EC-SWAP-PRO, LOW and HIGH are no longer two fixed speeds: they are the lowest and highest speed of the fan. When the system switches it on, it starts at LOW; then a sensor in the air returning from the rooms decides its speed: the staler the air, the faster it runs, up to HIGH. Two selectors on the board set the level where it starts to speed up and the level where it reaches HIGH, in steps of 100 ppm (0 to 1600 ppm with a CO₂ sensor). The system stays in charge of starting and stopping; its high-speed command is no longer followed, except with a jumper on the board.
Day to day, case by case
The existing control always decides whether the fan runs; EC-SWAP-PRO only chooses how fast, between LOW and HIGH, based on the sensor. At the slightest doubt about the reading, it returns to the two speeds the operator already knows.
The fan stops at once, whatever the air quality: the time schedule, fire alarm or frost protection stay in charge.
The fan starts smoothly at LOW, while the motor gets up to speed and the reading settles; the sensor then takes over.
Below the lower threshold, the fan stays at LOW. Above it, it speeds up as the air gets staler, up to HIGH at the upper threshold. It rises quickly when a room fills up and comes down slowly, without hunting around a threshold.
With a jumper on the board, the fan runs at HIGH for as long as the order lasts, for a purge or night cooling. Without the jumper, the order is ignored: the sensor stays in charge.
Sensor unplugged, cable cut or impossible value: EC-SWAP-PRO returns to the two speeds of EC-SWAP, LOW or HIGH depending on the order received, and an indicator lights up. Ventilation continues; control resumes by itself once the reading is valid again.
The module restarts at LOW if the system calls for the fan, then resumes control, without a jolt.
Supply and extract together
On a dual-flow air handling unit, each air stream has its own EC-SWAP-PRO, but a single sensor in the return air is enough. The module it is connected to passes its demand on to the other: supply and extract speed up and slow down together, each between its own LOW and HIGH. If the link between the two modules is cut, both return to the two speeds.
What the installer sets
- LOW and HIGH
- The lowest and highest speed, on two potentiometers, as on EC-SWAP.
- Lower and upper threshold
- Two selectors, in steps of 100 ppm: one sets the threshold where the fan leaves LOW, the other where it reaches HIGH.
- High-speed jumper
- With the jumper, the high-speed command forces HIGH; without it, the command is ignored.
- Dual-flow air handling unit
- LOW and HIGH of each air stream are set on measured airflows, to keep the intended balance between supply and extract across the whole range.
EC-SWAP-PRO is announced for 2027: this behaviour reflects current plans; the operating instructions will give the final settings.
Specifications
| Function | Conversion of a two-speed induction motor control into EC motor control, with built-in air quality control |
|---|---|
| Air quality control | From a CO₂ or VOC sensor in the return air: the EC motor setpoint varies between LOW and HIGH, air volume increased when pollution rises, reduced during off-peak periods |
| Minimum and maximum setpoints | Two potentiometers on the board: LOW for the minimum setpoint, HIGH for the maximum setpoint |
| Sensor thresholds | Two selector switches graduated from 0 to 16 · CO₂ sensor: 0 to 1600 ppm, i.e. 100 ppm per step · one sets the threshold at which the speed leaves LOW, the other the one at which it reaches HIGH |
| Existing control | Low-speed command: start at LOW · high-speed command: taken into account only with a jumper on the board |
| Control | Variable air volume from a pressure or temperature sensor |
| Multiple sensors | Several air quality sensors can be connected, for example room sensors, via a gateway |
| Unit | One module per airflow |
| Supply / extract link | Two paired modules, one per air stream: the supply-to-extract airflow ratio is set at commissioning and held across the whole modulation range |
| Manufacturer | Wellset |
| Restocking lead time | Confirmed in the quotation |
Before / after
Before: an induction motor with two fixed speeds, whether the air is clean or polluted. After: EC-SWAP-PRO starts the EC motor at LOW, then the air quality sensor varies its setpoint up to HIGH.
What changes: the connection of the contactors, one module per airflow and its sensor, sold separately. What stays the same: the control system and the controller program.
60 seconds, no sound.