MAIN SWITCH
The unit is equipped with a main switch. The main switch starts the control circuit.
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TIMER
The timer is located in the control circuit and has a battery back-up. At delivery or after a long downtime, the battery in the timer might need power for a few minutes to get charged and be able to start. The timer is pre-set to run from Monday till Friday, 6:00 am to 6:00 pm, but can be re-programmed according to the instructions in the supplied Instructions for use and maintenance manual. |
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INDICATION
The indication in the upper right corner of the timer shows either ON, coupling mode supply, or OFF, extract. By pressing the + and – buttons you can easily alter between supply and extract. This will not change the original programming. |
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DOOR SWITCH
The door switch is located on the frame around the dashboard. It switches off all the functions (except for the clock) when the doors open. This is a precaution to avoid getting hurt on fans or electric battery. NOTE! Always wait for a little while after the doors are opened to make sure that the fans have stopped, before actions in the unit are taken.
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START
To be able to start the unit, you need to make sure that… 1. the unit has power. Check that the external safety switch is on (usually located on the wall behind the unit). 2. the master switch on the panel is set on mode “1”. 3. the indication on the timer is ON. 4. the switch/handle for the supply air speed is not set on 0. 5. and that the safety switch (the door switch) is depressed. |
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START CONTROL
To make sure that the unit starts even though the doors are open you can, under great caution, quickly press the door switch by hand. After a few seconds both fans should start to rev up. The door switch is normally held in by the closed door. |
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FAN SPEED
The speed of the fans can be individually set to five paces. Then the ventilation balance can be chosen depending on the different pressure drops on the supply side and extract side.
Long ducts and many bends result in a large pressure drop, that side might then need a higher speed in order to get a balanced airflow. The speed and thus the airflow is set with the two handles on the dashboard. |
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POST-HEATING
In the unit, in front of the supply air fan, there is a heating coil that adds heat when the outdoor air is too cold for the heat exchange to suffice. The post-heating coil can be for either electric heating or water heating. At electric heating the changeover switch labelled “heat switch” has to be set on mode “1” in order for the battery to start.
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TEMPERATURE SETTINGS
Should you turn the thermostat knob for SUPPLY AIR TEMPERATURE on the panel to a value that exceeds the temperature of the supply air, the post-heating starts. The built-in automatic adjustment then strives to maintain the set temperature of the supply air.
A suitable supply air temperature when using the unit’s low impulse device is 2-4 degrees under the room temperature. 18°C is a good general setting. The supply air will then “float” over the floor and ventilate the entire room before it heats up and rises towards the ceiling, to later be extracted. |
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INTERLOCK
The extract air fan and the post-heating are interlocked over the supply air fan. This means that if the supply air fan’s speed knob is set on “0”, the extract air fan will not start and for safety reasons nor will the post-heating. |
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HEAT EXCHANGER
Kuben room units are equipped with flat heat exchangers. This type is preferable when you want a functional and reliable unit with a minimal transfer of odours and particles between the supply air and extract air. When it is cold outside, the heat exchanger continuously has a cold and a warm side. At a low outdoor temperature and high indoor humidity, the condensation therefore outcomes on the cold metal sheet. This condensation normally gets absorbed on the supply air side and is then evaporated in the supply air. It is then taken back into the room.
At an even lower temperature there is not enough time for the condensation to be evaporated into the supply air, which will make the heat exchanger freeze. A sensor feels this and will instantaneously stop the supply air fan in order to let the warm air melt the ice. The supply air fan will then automatically start again. |
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OCCUPANCY SENSOR
Some units are equipped with a sensor that records heat radiation from people (and pets), a so called IR-detector. The IR-detector senses any changes in the heat radiation. It is passive, i.e. does not generate any radiation of its own but seeks radiation in its coverage area. When the sensor detects a change in the room’s presence, it will automatically make the unit increase its flow from low speed to the set speed on the dashboard when somebody enters the room. When the room has been emptied of people, the unit continues on the higher speed for a few minutes before it automatically slows down to the lower speed.
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| UNITS WITH ELECTRIC POST-HEATING |
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OVERHEATING PROTECTION
The post-heating radiator is equipped with a manual and an automatic overheating protection. Should the electric battery get overheated, the overheating protection trips and cuts the power to the electric battery. The extract air fan stops while the supply air fan winds up to the maximum speed in order to cool the electric battery during the time set on the timer. This timer, located behind the dashboard, is factory set and shall not be touched. If overheating occurs during normal operation with closed doors, the unit shall be stopped and a service technicians be contacted.
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COOLING
If you open the unit’s doors at the same time as the supply air calls for electric heating, the electric battery can get to hot, which will trip the overheating protection. This can be a result of the following: at normal operation the timer stops the unit. The extract air fan will stop and the electric heating is cut but the supply air fan will continue running for about 3-4 minutes (depending on the timer’s settings) to cool the hot electric heating rod.
If you open the unit’s doors when it is running, the door switch will for safety reasons stop the electric heating as well as both fans. There will then be no cooling of the electric heating rods and these might feel very hot, even though both the heat switch and the temperature are set on zero.
The overheating protection might here be activated.
The electric heating rods, which during operation are cooled by the outdoor air, can continuously seem to get warmer and eventually even start to glow a bit. Since there is no power supply to the electric battery, the electric rods will soon cool down. This is absolutely normal but to avoid worry and triggered overheating protection, you should turn of the heat on the heating switch for a few minutes before opening the doors, or turn off the unit on the timer so that the timer can decide when the supply air fan shall stop and the door can be opened. |
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RESET
If the electric heating does not start when you close the doors and start the unit, which might happen, especially in cold weather, you need to reset the manual overheating protection. It is a small button located directly on the electric battery’s junction box. When this button is pressed the electric battery will get warm if the heat switch is on, the temperature control calls for heating, the timer is on, the supply air fan’s switch is not on zero and the door switches are pressed-in. |
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| UNITS WITH WATER POST-HEATING |
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POST-HEATING WITH WATER
In the unit there is, before the supply air fan, a water battery that adds heat when the outdoor air is too cold for the heat exchange to suffice. The battery is dimensioned to fit the house’s ordinary heating system. The temperature is controlled by automation equipment built-in into the unit. The only thing that normally has to be thought of is to set the right supply air temperature.
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TEMPERATURE SETTINGS
If you turn the temperature switch for SUPPLY AIR TEMPERATURE on the panel to a value that exceeds the temperature of the supply air, the valve for hot water will open. The built-in automatic control then tries to maintain the set supply air temperature. |
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ANTI FREEZE
The post-heating battery is equipped with automatic antifreeze. If the temperature by the antifreeze sensor drops below +4°C, the fans will stop and the valve for hot water opens fully. At the same time the control unit sends out an alarm. You can get an external indication of this alarm if it is connected to the unit’s coupling part/insertion part (inkopplingsdel). If the antifreeze is triggered during normal operation, the unit shall be stopped and a service technician be contacted. The antifreeze can be reset with the reset button marked ALARM on the regulator. The regulator is located behind the dashboard.
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DOWNTIME HEATING
When the supply air fan stops, the regulator passes over to downtime heating. The antifreeze sensor then becomes the main sensor, with a setpoint of 25 degrees. The advantage of downtime heating is that you, when restarting, have a warm battery which makes the risk of freezing minimal. You will also avoid unpleasant draught when starting the unit. |
