Enclosure heaters with fan
Specifications
Automation cabinet enclosure heaters with fans are used in electrical cabinets and switchboards in cases where air convection inside the cabinet is difficult, air convection in the heater installation area is difficult, or for targeted heating of specific equipment inside the cabinet.
Rated voltage, V: 12; 24; 110; 220
Starting current, amps: 2
Maximum surface temperature, °C: 105
Degree of protection: IP20
Permissible operating temperature, °C: -40..+70
Permissible storage and transport temperature, °C: -40..+70
Mount type, mm: DIN rail 35
Connection type, mm²: terminal connection 3 x (0.5..2.5)
Description
The enclosure heaters with fan case consists of an aluminum radiator. Body parts are powder coated. An axial fan is installed at the end of the radiator. A resistive heater and a thermal relay are built into the radiator, which limits the surface temperature. As standard, heat-resistant terminals are installed in enclosure heaters for connecting the power supply. Available on request with cable connection.
The heating device consists of aluminum plates-radiators, a heating element and heat-resistant leads. Also, to eliminate overheating, it is necessary to additionally install a thermal relay on the enclosure heaters with fan which will limit the temperature and heating time.
To connect the enclosure heaters with a fan, heat-resistant terminals are mounted, but it is possible to connect it in the form of a wire of the length you need. Intmax offers enclosure heaters with standard fan powers of 100, 150, 200 and 250 W. Overall dimensions of heaters for automation cabinets are also different.
Model variants Enclosure heaters(EH)
| Model | Power, W | Dimensions radiator, mm | Dimensions WxHxD, mm | Weight, kg |
| EH 115*92*80;0.1*220;1 | 100 | 115х92х54 | 155х110х99 | 0,7 |
| EH 155*92*80;0.15*220;1 | 150 | 155х92х54 | 195х110х99 | 0,9 |
| EH 200*92*80;0.2*220;1 | 200 | 200х92х54 | 240х110х99 | 1,1 |
| EH 150*122*80;0.2*220;1 | 200 | 150х122х80 | 190х141х99 | 1,5 |
| EH 185*122*80;0.25*220;1 | 250 | 185х122х80 | 225х141х99 | 1,8 |
Connection types
How to choose
Pp – the power of heat losses to the environment is determined by the formula:
Pp = S*ΔT*α, Wt
where
S – cabinet surface area, m2;
ΔT is the difference between the temperature inside the cabinet and the ambient temperature, K.
α is the heat transfer coefficient, W/(m2*K).
The heat transfer coefficient α at the boundary of the media “Air – smooth surface” is determined by the formula:
∝ =5.6+6v, W/(m2*K)
where v is the speed of air movement in the cabinet installation area, m/s.
Heater selection example.
Initial data: A cabinet of a standard form with dimensions of 2200x600x400 mm. is installed in a closed unheated room. The minimum possible indoor temperature is -5°C. The minimum allowable operating temperature of the equipment installed inside the cabinet is +5°С.
Surface area:
S=2(2.2*0.6+0.4*0.6+2.2*0.4)=4.88m2
Temperature difference:
∆T=5-(-5)=10K
Heat transfer coefficient:
∝ =5.6+6*0=5.6 W/(m2*K)
Heat loss power to the environment:
Pp=4.88*10*5.6 = 273.28 W
Taking into account the fact that downtime is possible for the equipment inside the cabinet, we accept
∑Pob =0
In this way:
∑Pload>273.28 W
In this case, it is necessary to install two heaters: one with a power of 180W and one with a power of 120W.