25
Smarty 4X V
www.salda.lt
In this system you can set a normal state of every digital input, i.e. indicate whether the contactor is normally open or closed (Normally Open (NO),
Normally Closed (NC)). The fire protection contactor must be NC as in case of fire the contactor may break due to burnt cable.
Digital inputs are configured in the service environment window SERVICE › DIGITAL INPUTS.
In this system, three 0-10V DC sensors and eight temperature sensors can be used. The following can be connected to two 0-10 VDC inputs:
› supply air RH sensor;
› exhaust air CO
2
sensor;
› exhaust air RH sensor;
› supply air pressure switch;
› exhaust air pressure switch.
If pressure switches for more than 3000 Pa are being used, it’s necessary to change pressure scale at „SERVICE › SENSORS › AIR PRESSURE
1.33.1 Supply Air Heater
The heater additionally pre-heats the supply air when the heat exchanger power is insufficient. It is controlled by means of a PID controller based on
the temperature indicated in the system and based on data of the supply air temperature sensor. One supplied air heater can be connected to this
system. It may be either electric or water heater. PID controller coefficients are set in the adjuster environment window ADJUSTER › PID CONTROL
-
LERS ADJUSTING.
Possible options of supplied air heaters in this system:
› Supplied air heater is not used;
› Electric heater is controlled by 0..10VDC signal;
› Electric heater is controlled by On/Off signal. PWM control interval in seconds is set to control it;
› Water heater.
Types of heaters are indicated in the service environment window SERVICE › HEATERS. Also it is possible to swap connection of the pre-heater and
heater protections and control signals.
1.33.2 Electric Heater Overheat Protection
The electrical heater can have two protections: automatic and manual. The automatic protection automatically deactivates when the heaterhas cooled
down, and the manual protection should be deactivated by pressing the switch on the heater.
The automatic protection is checked at all times, while the manual protection is checked only when the heater is activated.
When the automatic protection is activated, the heater and its power circuit are disconnected, a message is shown and cooling is ensured by an in
-
creased air flow. The automatic protection is eliminated automatically.
The fan speed is controlled according to the supply air temperature, i.e. if the supply air temperature drops below the minimum, the fan speed is
reduced. When the manual protection is activated, the heater and its power circuit are disconnected, a warning is shown and the indicated action is
performed.
According to the factory settings, blowing is carried out a the full capacity in order to ensure the maximum cooling of the heater because there is a
probability that the manual protection may be blocked and leave it operating. Certainly, if it is activated properly, when blowing at the full capacity in
winter, the supply air temperature falls rapidly to the critical level and the system is shut down in any case.
The protection is configured in the window “SERVICE › HEATERS” of the service environment.
1.33.3 Cooling of Electric Heaters
If the used electric heater and the system wants to shut down the fan, the heaters are switched off and they are cooled down by blowing for an in
-
dicated time period. A user is notified of heater cooling. Time is indicated in the service environment section SERVICE › HEATERS › ELECTRICAL
HEATERS COOLING. The fan speed is controlled according to the supply air temperature.
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 pre-heaters are controlled based on frost protection. The water pre-heater, as the same type heater, is pre-heated before system startup. In
winter the circulation pumps are always rotating, and in summer they are switched on for 5 minutes for preventive check at indicated time intervals.
Possible options of outdoor heaters:
› Supply air pre-heater is not used;
› Electric pre-heater is controlled by 0..10 VDC signal;
› Electric pre-heater is controlled by On/Off signal. PWM control interval in seconds is set to control it;
› Water pre-heater.
Types of pre-heaters are indicated in the service environment window SERVICE › HEATERS.
Only either pre-heater or heater can be connected to
MiniMCB basic board.
is, the shorter the time interval between deicing cycles. The exhaust air temperature and the pressure switch of the heat exchanger can extend time
intervals between deicing cycles and to extend the deicing time, i.e. if the minimum time interval after a deicing cycle has elapsed and the pressure
valve has not yet been activated, then its activation is awaited; otherwise, if the required conditions are not achieved within 5 minutes during deicing
(the pressure valve does not reset or the exhaust air temperature does not increase), then deicing is extended. If the protections according to the pres
-
sure switch and/or according to the exhaust air temperature are not activated, then deicing cycles take place at minimum intervals.
