Lps Nf C 17-102

The Chinese University of Hong Kong Two Integrated Teaching Building Lightning Protection System Calculation Tower II

Length of Building Width of Building Height of Building Relative Structural Location Structural Coefficient Structural Contents Structural Occupancy Lightning Consequency

C1 C2 C3 C4 C5

Equivalent Collector Area Lightning Flash Density Maximum Lightning Flash Density Expected Direct Lightning Stroke Frequency on a Structure Accepted Direct Lightning Stroke Frequency on a Structure

Ae Ng Ng max Nd Nc

139337 0.042 0.083 0.029 0.022

E

0.243 Level III 14.7 60 5 45 89.4

Since

(m) (m) (m)

61.7 30 70.2 0.25 0.5 1 1 5

Nd > Nc , THE PROTECTION IS REQUIRED.

Effectiveness Protective Level Peak Current Initiation Distance Height of ESE Pole Selected Triggering Advance Protective Radius Thus, min. no. of ESE Poles required: 1

I D DT Rp

(kA) (m) (m) µs (m)

The Chinese University of Hong Kong Two Integrated Teaching Building Lightning Protection System Calculation Tower I

Length of Building Width of Building Height of Building Relative Structural Location Structural Coefficient Structural Contents Structural Occupancy Lightning Consequency

C1 C2 C3 C4 C5

Equivalent Collector Area Lightning Flash Density Maximum Lightning Flash Density Expected Direct Lightning Stroke Frequency on a Structure Accepted Direct Lightning Stroke Frequency on a Structure

Ae Ng Ng max Nd Nc

Since

(m) (m) (m)

90 60 82 0.25 0.5 1 1 5

### 0.042 0.083 0.040 0.022

Nd > Nc , THE PROTECTION IS REQUIRED.

Effectiveness Protective Level Peak Current Initiation Distance Height of ESE Pole Selected Triggering Advance Protective Radius Thus, min. no. of ESE Poles required: 1

E I D DT Rp

(kA) (m) (m) µs (m)

0.445 Level III 14.7 60 5 45 89.4

Peak Initiation Current I Distance (kA) D (m) E>0.98 Level I + Additonal Measures Level I 2.8 20 0.98≤E<0.95 Level II 9.5 45 0.80≤E<0.95 Level III 14.7 60 0≤E<0.80 Effectiveness E

1 2 3 4

Associated Protection Level