VENTS NK 250-3,6-3 U
Duct electrical heaters are designed for supply air heating in round duct ventilating system. The heaters are applied in heating, ventilation and air conditioning systems for various premises.
The casing and the terminal box are made of galvanized steel and the heating elements are of stainless steel. The heaters are equipped with rubber seals for connection to the air ducts.
NK duct heaters are equipped with two overheating protection thermostats:
Each standard size has several electric capacity options. The higher capacity can be attained by means of installation of the heaters in series. All the three phase heaters have star connection.
|DUCT ELECTRIC HEATER WITH INTEGRATED TEMPERATURE CONTROL|
The NK heaters are available in modifications NK...U with a temperature controller for the heaters with power demand from 0.6 up to 2.4 kW or with a control unit for the heaters with power demand from 3.0 up to 9.0 kW to maintain set air temperature in the air duct.
The temperature control knob with temperature range from -10 °C up to +40 °C is placed on the junction box front panel. The NK…U heater is equipped with a builtin temperature sensor located inside of the air duct.
The thermal switch with manual reset actuated at +60 °C is used for the thermal overheat protection.
The NK…U model with a control unit is equipped with a triac power control unit. Power control is effected by means of switching on/off the maximum load commutated by the semiconductor device that is free of any mechanical wear parts. The load commutation starts at zero current and load to disable any magnetic field interferences.
The NK…U heater includes two overheat protection thermostats:
After cooling the thermostat closes the heater control circuit.
Operation logic options for the NK…U heater with a control unit:
The temperature is set with the integrated potentiometer. Optionally, an external 0-10 V control signal from another control unit may be connected to the control unit, which corresponds to the temperature 0 up to +40 °C.
Offered temperature sensor options for the NK...U heater operation logic based on temperature sensor readings (not included into delivery set):
The heater design ensures its mounting on the round ducts in any position by means of clamps. The air flow direction shall match the pointer on the filter. The duct heaters can be installed in any position except for with the electric control unit below to prevent liquid penetration and wiring short circuit.
The mounting shall be performed in such a way as to enable uniform air distribution along the entire cross section.
The air filter shall be installed at heater inlet to protect the heating elements against pollution.
The minimum distance between the heater and other system elements is no less than two connecting diameters.
The duct heaters are designed for minimum air flow speed 1.5 m/s and the maximum operating outlet temperature 40 °С. In case of speed control option ensure the minimum air flow through the heater.
Power supply to the heater shall be disabled if the fan is not running.
To ensure the correct and safe heater operation he automation system can be applied to ensure the complex control and protection:
NK 250-3,6-3 U
|Minimum air capacity||375||m³/h|
|Number of heating coils x capacity||3 х 1,2||kW|
|Air duct diameter||250||mm|
|Duct||for round air ducts||-|
|Series||Air duct diameter, mm||Heater power [kW]||Phase||Options|
|NK||100; 125; 150; 160; 200; 250; 315||0,6; 0,8; 1,2; 1,6; 1,7; 2,0; 1,8; 2,4; 3,0; 3,4; 3,6; 5,1; 6,0; 9,0||
|U – integrated temperature control|