Calculation of lightning protection grounding
Grounding pole
1.1 grounding pole production and installation: quota set 2-688 ~ 2-695, can be divided into steel pipe grounding pole, angle steel grounding pole, round steel grounding pole and grounding pole plate (block).
1.2 Description: grounding pole that grounding body, is buried in the ground and directly in contact with the earth to do with the metal conductor dissipation. The length of the grounding pole is calculated according to the design length, the design is not specified, each length is calculated according to 2.5 meters, if the design has a pipe cap, the pipe cap is calculated according to the processing parts. The grounding pole is generally used in small buildings, and no piling project.
2, grounding bus
2.1 grounding bus laying: quota set 2-696 ~ 2-700, can be divided into indoor grounding bus laying, outdoor grounding bus laying, copper grounding stranded wire laying.
2.2 Description: grounding bus refers to all grounding wires together after the grounding line, generally using flat iron or round steel, outdoor grounding bus is generally laid in the ditch, according to the design requirements before the laying of the trench, trench depth shall not be less than 0.5 meters, and then buried in flat iron. Grounding busbar does not do the role of the bulk flow, grounding busbar and grounding body and grounding branch line generally use welding connection. Outdoor grounding busbar ditching trench bottom width of 0.4 meters, on the width of 0.5 meters, the trench depth of 0.75 meters, per meter ditch length of the amount of earth for 0.34 cubic meters, such as the design requirements of the depth of burial is different at the same time, can be adjusted according to the design of the amount of cubic meters.
2.3 grounding busbar calculation of the amount of work should be designed according to the drawings of the horizontal length and vertical length only and * 1.039, the calculation of the main material costs should be based on the market price * the corresponding loss rate.
3, grounding jumper
3.1 grounding wire jumper installation: quota set 2-701 ~ 2-703, can be divided into grounding jumper, frame grounding and steel aluminum window grounding.
3.2 Description: grounding jumper: lightning protection grounding should form a closed and loop after grounding, grounding jumper should be used at the disconnection, where the grounding network with bolts or rivets connected to the place, should be welded grounding jumper, jumper is generally used flat steel and round steel. 3.3 grounding jumper according to 40 * 4 flat steel considerations, the use of open connection, pipe fittings across the use of flange connecting bolts, rails using fishtail plate fixing bolts, parallel pipelines using welding for comprehensive consideration.
3.4 Frame grounding is considered according to the outdoor steel structure or concrete structure grounding, each grounding span includes the horizontal grounding within 4 meters.
3.5 Steel-aluminum window grounding uses No. 8 round steel connected to the window at one end and to the main reinforcement of the ring beam at the other end.
3.6 the use of foundation reinforcement for grounding, set 2-751 equalized pressure ring laying subheading (but equalized pressure ring laying subheading does not have round steel and other main materials, only considered the lap weld between the steel bar and the steel bar, so I personally think that the use of foundation reinforcement for the grounding network in addition to the equalized pressure ring counting, but also should be calculated according to the number of foundation reinforcement spanning the number of connections).
3.7 equipotential box and local equipotential box box box connection set of ground span * 0.5 coefficient, the box and then a separate set of quotas, local equipotential box should be set of junction box installation subheading, total equipotential box set of junction box installation subheading.
4, lightning rod
4.1 lightning rod production and installation: quota set 2-704 ~ 2-740, lightning rod production can be divided into the production of steel pipe lightning rod, round steel lightning rod system, lightning rod installation can be divided into mounted on chimneys, mounted on a flat roof, pulling the wire installation, mounted on the wall, mounted on the top of the metal containers, mounted on metal container wall, mounted on the structures and independent Lightning rod installation.
4.2 The fabrication of lightning protection does not include the processing of the base or the price of its own main material, and the calculation of the cost of the main material should be based on the current price * attrition rate.
4.3 independent lightning small needle installation does not include the production of the needle body, needle body processing and production according to the "general iron components production" quota calculation.
5, semiconductor?
5.1 semiconductor less long needle lightning device installation: quota set 2-741 ~ 2-743.
5.2 semiconductor less long needle lightning device installation to set as a unit of measurement, according to the design of the installation height, respectively, the implementation of the corresponding quota, the device itself by the equipment manufacturer complete sets of supply. 6, lightning lead
6.1 lightning lead laying: quota set 2-744 ~ 2-747. lightning lead laying can be divided into the use of metal components lead, lead along the building structures, the use of the building reinforcement lead and disconnect the card production, installation. 6.2 such as the steel structure of the plant using its steel columns to do the lead line should be applied to the use of metal components lead down.
6.3 along the building structures lead down is generally used round steel, flat iron along the buildings and structures laying lead down, calculate the amount of work should be designed according to the drawings of the horizontal length and vertical length only and * 1.039, calculate the cost of the main material should be according to the market price * the corresponding rate of loss. But now there are a lot of rebar connection methods, generally no longer use the tie and lap welding, not part of the flash butt welding and taper thread joint connection, these construction are completed by the rebar workers, flash butt welding can be said that do not need an electrician to weld again, taper thread joints in general can be completed the electrical pathway, but for safety reasons, such a connection is also required to carry out the cross connection. So I personally think that this amount of work whether it is not by the reinforcing steel workers to complete or have an electrician to complete, we this amount of work should still be calculated, at least in the column reinforcing steel spanning is still completed by the electrician.
6.5 electrical equipment grounding lead installation has been included in the equipment installation quota, should not be double-counted.
6.6 disconnect the card is to test the resistance value of a test point, generally installed in the junction box or box with dark, apply the quota should be based on the design and construction of a separate set of junction box or junction box quota.
7, lightning net
7.1 lightning net installation: quota set 2-748 ~ 2-252 subheading, can be divided into laying along the concrete block, laying along the folding plate bracket, concrete block production, even pressure ring laying and column reinforcement and ring beam reinforcement welding
7.2 laying along the concrete block is the lightning net bracket in the top of the concrete block, the concrete block set of concrete block production quota subheading, the quota of lightning net Bracket spacing according to 1M considerations. Along the wall plate bracket lightning net also implement the subheading, but do not calculate the amount of concrete block production, the bracket in the quota integrated consideration, no longer calculated.
7.3 along the folding plate bracket laying (I have not seen this, according to a friend said that this applies to the folding type of roof.
7.4 concrete block production is no longer said.
7.5 equalized pressure ring laying this is generally found in the high-rise, used to prevent lightning side strike. Can be laid along the outer wall can also use the ring beam reinforcement to lay, laying the outer wall personally think you can set the lightning net subheading, the use of the ring beam reinforcement laying sets of pressure ring laying subheading.
7.6 column reinforcement and ring beam reinforcement welding this is when the floor has a local equipotential box, in the column on the lead reinforcing bars and ring beam reinforcement welding, welding according to the two main bars to consider. Foundation beam and column reinforcement welding can also be implemented in this subheading.