AC voltage, V 380 2. Section length wire at 220 V: – PNSV 1.0 mm, m 80 – PNSV 1.2 mm, m 110 – PNSV 1.4 mm, 140 m 3. Specific heat capacity of the wire: – for reinforced structures, w / rm. 30-35 – for the non-reinforced structures, w / rm. 35-40 4. Recommended supply voltage, V 55-100 5. The average value of the resistance of conductors: – PNSV 1.2 mm, W / m 0.15 – PNSV 1.4 mm, W / m 0.10 6.
The method parameters: Power specific, kW/m3 1.5-2.5 consumption wires p.m./m3 50-60 cycle thermo-keeping structures, days 2.3 The need for electricity for heating determined by calculations based on the type of structures that are characterized by a quantity equal to the ratio of the area cooled to the volume of concrete. As a rule, it is affected by ambient temperature, degree of protection construction of the cooling rate of heating of concrete in one hour. In the calculations, consider the following indicators: 1 kilowatt / hour allocates 860 kcal of heat. Specific heat of concrete 620 kkal/m3hoS that this temperature of 1 m3 of heavy concrete rises by 1 C. when a m3 of concrete hardening allocates an average of 500 kcal / hour. Heated concrete must be performed at low voltage and high amperage in the heating elements. For this we recommend use a special heating substation for concrete stamps TSDZ, St. Petersburg or KTPTO. Installed power substations in the voltage depends on when heating of the concrete.