How to calculate the formula for trunking and tray

The calculation formula is as follows:

The width of the cable tray is designed for power cables and control cables, and the calculation formula is different:

The above formula can be used for power cables, and this formula can be used for control cables: b=s h=s0 40% (s=s0 40%)

where s0 = n1 * s1 + n2 * s2 + n3 * s3 + .

n1,n2,n3...is the number of corresponding cables; s1，s2,s3...is the cross-sectional area of each cable (calculated according to the outer diameter of the cable):

S --- cross-sectional area of the bridge space.

h--- The formula of your calculation method for the net height of the tray space is correct, that is, the calculation method of the cable diameter is wrong, and the calculation should be more accurate in this way.

The square of the wire radius (mm) and the number of strands.

Such as 48 strands (each strand of wire radius in mm) square wire:

48 = squared.

The production of the bridge elbow is actually very simple! The calculation of the degree of elbow can be calculated with a formula! For example, the formula for a 30-degree climb elbow is x=

Length and width = bridge area.

It's pi. is the fill factor.

It means that only 60% of the thread volume is estimated, if 100% then we will not be able to thread ) 2 = the area of a single thread.

According to the above formula: the length and width are all 10, and the cable radius is 1, that is, (10*10) (

The formula and calculation method of bridge making are as follows:

First, the bridge production formula is as follows:

50 * angle iron mass + 50 sets * 2 * 2m each * through wire mass = total mass.

Second, the calculation method of bridge production is as follows:

1. The contact resistance of each fixing bolt of the galvanized cable tray direct plate.

It should be less than, at this time the cable tray can be used as a grounding trunk (the powder spraying cable tray should not be used as a grounding trunk), and the resistance value of each cable tray can be calculated as follows:

r=ρ·l/s。

where: 15 10 -6 cm (20).

l = length is calculated as 100mm.

s = cross-sectional area cm2.

2. When the cable tray is installed and connected as a whole, the resistance of each ladder edge (or each cable trough) is:

r=l(r+1/3r’)。

Where: r - ladder edge, that is, (cable trough) total resistance (m).

r--ladder unit length resistance (m m).

The height is the height we want to turn, the bottom edge is the length of the elbow after the elbow is done, if we want to put the elbow we do just to the bracket from our meters, we will use this bottom edge, m - 20 cm (bottom edge) = 130 cm, then we can start to do the elbow at 130, and the elbow can be placed on the bracket of the meter after doing it.

It is recommended to leave a little, because the stent may not be straight, and the stent cannot be adjusted to this side if it is stuck directly.

30 degree elbow: hypotenuse = height x 2 bottom edge = height x up-down cut-out width = side plate height of the trunking x left-right flip cut-out width = bottom plate width of the trunking x.

For example, if a 200 (bottom) x 100 (side) trunking needs to be turned to the left 20 cm (height) after meters, we can calculate it as follows: hypotenuse 40 = 20 x 2 bottom edge 34 = 20 x left and right flip cut width = 100 x.

The calculation formula is as follows: the width of the cable tray is divided into electric Chang cover Liyou Xunyu cable and control cable, and the calculation formula is different: the above formula can be used for power cables, and the formula can be used for control cables:

b=sh=s0 40% (s=s0 40%), where s0=n1*s1+n2*s2+n3*s3+.n1、n2、n3...is the number of corresponding cables; s1、s2、s3...

is the cross-sectional area of each cable (calculated according to the outer diameter of the cable): s - cross-sectional area of the bridge space h - the clear height of the bridge space. Your calculation method and formula are correct, but the calculation method of the cable diameter is incorrect, and it should be more accurate.

The square of the radius of the wire (mm) The number of strands, for example, 48 strands in square meters (the radius of each strand is in millimeters) square meters.

In the design calculation, if the actual load of the cable tray is expressed by the total g:

Then: send the balance.

g total = n1g1n2g2n3g3......

where: g1g2, g3, ......They are the unit length weight of various specifications and models of cables in the tray. The unit is (kg m), N1, N2, N3 is the number of cables of the same type and specification.

The determination of the width b of the cable tray is different with the different working systems of the power cable and the control cable. Because the power cable is generally a single-layer horizontal discharge in the tray, the width b of the installation tray is:

b=n1(d1+k1)+n2(d2+k2)+n3(d3+k3)+…

where: d1, d2, d3......The outer diameter of the cable is made for all kinds of dust in the tray, and the unit is mm.

n1、n2、n3……is the number of cables of the same type and specification mentioned above.

k1、k2、k3……is the spacing between the above cables when placed. Its minimum value should be greater than 1 4 of the cable diameter.

In general, the control cables can be either horizontally or stacked in the tray. The total cross-section s of the control cable in its tray does not exceed the total cross-section s s of the cable tray. 40% of the principle. The total cross-section s of the control cable is:

Among them: S1, S2, S3 ......The cross-sectional area (including the sheath part) of various control cables in the bridge is mm, d3......is the outer diameter of various control cables in the tray, the unit is mm; nnn……is the number of cables of the same type and specification mentioned above.

Formula and calculation method of bridge production 1, the actual load calculation of the cable bridge envy punch side frame g total = n1 * Q1 + n2 * Q2 + n3 * Q3 ......In the nn*qn formula: g is always the total load, q1, q2, q3 ......QN is the unit weight of each cable (kg m), N1, N2, N3 ......nn is the number of cables of the same type. (g total.)

1. The formula for calculating the actual load of the cable tray:

g total = n1 q1 + n2 q2 + n3 q3......nn×qn

In the formula: g is always the total load, q1, q2, q3 ......QN is the unit weight of each cable (kg m), N1, N2, N3 ......nn is the number of cables of the same type.

2. Calculation of cable tray width

The determination of the width of the cable tray varies with the different working systems of the power cable and the control cable. Because the power cable is generally a single-layer water vertical wheel flat discharge in the bridge, the width b of the installed bridge is:

b=n1×(d1+k1)+n2×(d2+k2)+n3×(d3+k3)+…nn×(dn+kn)

In the formula: d1, d2, d3......dn is the outer diameter of various cables in the tray, and the unit is mm; n1、n2、n3……nn is the number of cables of the same type and specification mentioned above; k1、k2、k3……is the spacing of the above cable placement, and its value should be at least greater than 1 4 of the cable diameter.

1. There are 6 connecting holes at each end of the bridge height, and 12 connecting holes at each end when the height is high.

2. Support spacing: The support spacing should be less than or equal to the allowable load and support span of the load curve.

3. Bridge width: When selecting the width of the cable tray, a certain spare space should be left for future cable use.

4. Partition laying: When there are fewer power cables and control cables, they can be installed in the same cable tray, but the power cables and control cables must be separated and laid with a partition plate in the middle.

5. Cable fixing: When the bridge tray is laid horizontally, the connection between the bridge should be set at the span 1 4 as far as possible. Horizontally oriented cables are fixed every 2 meters or so, and vertically oriented cables are fixed every 2 meters or so.

The method and calculation formula of the bridge are as follows:

Degree elbow answer thick:

Beveled edge = high lift x bottom edge = height, up-and-down cut-out width = side plate height of the trunking x left-right flip cut-out width = bottom plate width of the trunking x .

For example, if a 200 (bottom) x 100 (side) trunking needs to be flipped up 20 cm (height) after meters, we can calculate it as follows: (hypotenuse 28 = 20 x bottom edge 20 = 20 upside and up cut width = 200 x.)

Degree elbow: hypotenuse = height x 2 bottom edge = height x up-down cut-out width = side plate height of the trunking x left-right flip cut-out width = bottom plate width of the trunking x.

For example, if a 200 (bottom) x 100 (side) trunking needs to be turned to the left 20 cm (height) after meters, we can calculate it as follows: hypotenuse 40 = 20 x 2 bottom edge 34 = 20 x left and right flip cut width = 100 x.

Calculation formula for cable trays.

1. The load g calculation formula of the cable tray: g-n1*g1+n2*g2+n3*g3+.where:

n1、n2、n3...is the number of corresponding cables;gl、g2、g3...It is the weight per unit length of each cable (kg m).

The calculated value of g should be less than the allowable uniform load of the tray (refer to the load curve diagram of each tray), and when the cable tray is installed outdoors, the wind and snow load should also be included.

2. Calculation formula for cable tray width b: for power cables: b = n * (d1 + k1) + n2 * (d2 + k2) + n3 * (d3 + k3) + where:

n、n2、n3..is the number of corresponding cables;d1、d2、d3。for the outer diameter of each cable;k、k2、k3...

is the corresponding cable net spacing (K U003E 4).

Kiss, bridge formula: [pin width + height) x2 + ] thickness is determined according to the width, laughing bend below 400mm + 400mm or greater than 400mm + refers to the density of the bumper 7000 refers to the unit price per ton of steel.