Construction engineering electric power general configuration according to the need of hvac heating, electric heating engineering local climate conditions and the influence of building energy-saving insulation performance, through the heating of the heat load calculation to determine the heat electric heating power, as stipulated in the current construction of civilian residential building energy saving 65%, public construction requirements, up to 50% under the condition of heat preservation performance is good, with electric heating centralized control system of power installation engineering preferred for 65 ~ 80 w / ㎡, usually selected 18 w/m heating cable specifications. Improve the installed power (90-180 - w / ㎡) will increase speed at room temperature and maintain a wide temperature range (16-35 degrees), meet the needs of different people and comfort, but will increase the initial investment of power grid; Low installation power is the opposite; Adapt to different buildings and users. The total load of the project should also be taken into account for the reduction of the factors used in the season of summer air-conditioning and winter heating load.

The power supply voltage of the power distribution system in the building is selected according to the technical regulations of the ground radiation heating (jgj142-2004). The power supply is more than 12kw, and the power supply is 220/380v three-phase four-wire. Can be reference to the civil construction electrical design specification (JGJ16-2008), article 10.7.8 about lighting single-phase power distribution circuit current should not be greater than 16 a, each single phase electric heating power distribution branch circuit load also shoulds not be more than 3 kw. Power distribution branch circuits of the electric heating system, generally for the single-phase distribution, therefore, assign each other must keep balance, maximum load current should not exceed 115% of the average, minimum phase should not be less than 85% of the average load current.