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Smarty 2X/3X V
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In this system it is possible to indicate a normal status of every digital input, i.e. indicate whether the contactor is normally open or closed (Normally
Open (NO), Normally Closed (NC)). The re protection contactor must be NC as in case of re the contactor may break if a cable burns.
In this system two 0-10VDC air quality sensors and eight temperature sensors may be used.
The following can be connected to two 0-10VDC inputs:
• Supply air RH sensor
• Extract air CO
2
sensor
• Extract air RH sensor
• Supply air pressure sensor
• Extract air pressure sensor
0V and 10V values are indicated for these sensors. Types of temperature sensors:
• “None” – sensor is not connected
• “Remote” – remote sensor. Sensor temperature can be indicated via Modbus.
• “NTC 10K 3997” – NTC sensor is connected.
In this system all types of sensors and failure action are indicated. Possible failure actions:
• Do nothing – only warning is displayed
• Shut down the system – the system is shutdown, alarm is displayed.
• Emergency mode – operation is continued, but sensor-dependent functions are switched o. Warning is displayed.
MiniMCB controller has two independent communications lines. One line is dedicated for remote control panels, another one is for BMS network.
The line dedicated to the BMS network is galvanized. Used communication protocol – Modbus RTU.
1.33.1 Supply Air Heater
Supply air heaters are designed to additionally pre-heat the supply air when the heat exchanger heating power is insucient. The heater is controlled
by means of a PID controller based on temperature indicated by the system and data of the supply air temperature sensor. One supply air heater can
be connected to this system.
Possible options of supply air heaters in this system:
• Supply air heater is not used.
• Electric heater is controlled by 0..10VDC signal
• Electric heater is controlled by On/O signal. PWM control interval in seconds is indicated to control this heater.
Also it is possible to swap the connectors of pre-heater and heater protections and control signals.
1.33.2 Electric Heater Thermal Protections
The electric heater can have two protections. One is automatic, another one is manual. The automatic protection is automatically o when the heater
cools down, whereas the manual protection must be deactivated by pressing the switch on the heater.
When the automatic protection is activated, the heater and its power circuit are o, warning is displayed. Minimum switch-o time – 5 minutes. When
the protection is restored, the warning is no longer displayed.
If the manual protection is activated, the heater and its power circuit are o, an alarm is displayed, the indicated protection action is performed. By de-
fault, full speed blowing is performed so that maximum cooling of the heater is ensured as there is a probability that the manual protection can jam and
leave the heater running. Of course, if the manual protection is properly activated, the supply air temperature can quickly drop to critical temperature
during winter period if full speed blowing is on and the system would be shut down in any case.
1.33.3 Electric Heater Cooling
If an electric heater is used and the system wants to stop the fan, heaters are switched o prior to shutting fans down and they are cooled down by
blowing for an indicated period of time. A user is notied of heater cooling.
1.33.4 Outdoor Air Pre-Heater (not applicable to Smarty 2X/3X V 1.1 versions as they have integrated internal pre-heater)
Outdoor air pre-heaters are controlled based on anti-frost protection. Possible options of outdoor air heaters in this system:
• Supply air pre-heater is not used.
• Electric pre-heater is controlled by 0..10VDC signal
• Electric pre-heater is controlled by On/O signal. PWM control interval in seconds is indicated to control this heater.
Only either pre-heater or heater can be connected to
MiniMCB basic board.
consuming safeguards, i.e. if allowed, the supply air ow is reduced. If the protection does not help during the indicated period of time, then the other
protection is activated. Switching over from one protection to another one is done in a sequential order.
Outdoor and extract air recirculation is eective and energy-saving protection, but supplies the extract air to the supply air ow.
Outdoor air pre-heater can be used at full capacity or to maintain the set temperature. If temperature maintenance is selected, at rst the activated
protection will switch on the pre-heater at full capacity for a certain time period and then maintain the indicated temperature.
When using the bypass damper the supply air heater must be connected. The opening of the damper will reduce the cold air ow through the heat
exchanger, but it will cool down the supply air which must be heated up by the supply air heater. This protection slowly opens the bypass damper as
far as activation conditions are fullled. When suitable conditions are met the damper will be stopped for 5 min. and then slowly closed. If the supply
air temperature drops below the permissible limit (insucient heater power), then the damper will be closed by force based on supply air temperature.
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