Wellington’s ECR® 2 fan motors have many advanced features which enable OEMs to improve cooler performance. In this blog post, we will discuss one of these: timed behaviors. The timed behavior function allows the motor to run in one mode for a period, then change to a different mode, without any change in the control inputs. Creative use of this feature offers many opportunities to enhance and differentiate cooler behavior.
ECR 2 fan motors achieve simple on-off control by removing power from the brown (phase) wire. Alternatively, they are configurable for three “speed” settings, these are selected by connecting the black (control) wire to phase, to neutral, or not connecting it.
For any given connection position of the black wire (i.e. to phase, neutral, or nothing), the motor behavior can be configured so:
- the motor runs at a particular speed and direction till the black wire connection status changes;
- or the motor runs at a particular speed and direction for a fixed period (1-3600 seconds), then runs at a different speed and direction till the black wire connection status changes.
The speeds specified can be 0 RPM or anywhere between 300 RPM and maximum speed, and can be different for each of the three black wire states. Timed behaviors
can be either pre-configured at Wellington’s factory or configured on your cooler production line.
Example applications of the timed behavior function include:
- Condenser cleaning. Run the condenser fan in reverse for a period, either when the compressor is switched off or when it is switched on, to blow dust out of the coil, then either stop or go to a very low speed (for compressor deck safety ventilation). The reverse speed can be higher than the normal speed (for maximum cleaning) or lower (if needed to meet noise specifications: fans are usually louder when running backwards than forwards).
- Defogging. Run the evaporator fan at a higher speed for a period after the door has been opened, to help remove condensation from the glass.
- Condenser and evaporator delay start. When the compressor starts, there is a period where the system is charging during which very little heat transfer occurs. During this time, running the condenser and evaporator fans is just wasted power. Starting the fans sometime after the compressor, or starting them slowly then speeding up later, also spreads out the increase in noise level, making it less intrusive.
- Evaporator delay stop. When the compressor starts, residual refrigerant remains in the evaporator, giving “free” additional cooling capacity which can be extracted by running the fan for a period after the compressor stops. Running the fan for some time after the compressor, or slowing it down for a period before stopping it, also spreads out the increase in noise level, making it less intrusive.
- Boost mode. If the compressor has been running for a long period of time, it may need additional airflow from the condenser or evaporator to help it pull down or maintain temperature. The fans can be configured to increase speed after (e.g.) 1 hour of continuous running.
- Smart hush mode. If a hush mode has been enabled for the condenser fan (see our white paper on using multi-speed motors in condensers, available on our eBook here), the system can protect itself against users too aggressively using hush mode, by increasing the speed back to “non-hush” normal after (e.g.) 30 minutes of continuous compressor operation.
To view more content about our ECR 2 motor, check out our eBook here.