Furuno 9ZWWR2120, Руководство по установке

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S2E-17-0209_IM_WR2120_C
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2.3. Risk Assessment Conclusion
Values of the risk components for the unprotected structure are reported in the regulation.
The public service loss (L2) and the economic loss (L4) are relevant for this type of structure. It is
required to evaluate the need for protection. This implies the determination of the risk for L2 and
risk for L4 with the risk components and and to compare it with the
tolerable risk . Suitable protection measures will be selected to reduce the risk to or below
the tolerable risk.
According to the IEC 62305-2, calculation of the risk parameters is shown as follows:
Table A-4: Risk components for different types of damage and source of damage (IEC 62305-2)
Damage
Source of damage
S1 S2 S3 S4
D2
D3
Calculation of the risk components requirement is as shown in the Table A-5.
Table A-5: Weather radar at CWRP: Environment and structure characteristics
Use the
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A-4 and the Table A-5, risk assessment result will be
calculated. The result is shown in the Table A-6. Therefore considering current condition, the
weather radar is not protected by existing lightning rods. Total risk value is exceeded of the
tolerable risk value.
We’ll propose solution for this later, protecting the radar by additional lightning rod and adapt LPL
Class IV. Assessment for this solution is also shown in the Table A-6. According to the result is
almost half of the tolerable risk value, so the condition of the radar turned into safe.
Table A-6: Risk assessment result at CWRP
Type of damage Symbol Current Condition Protected by LPL IV
D2: Physical Damage
0 0
0 0
D3 failure of
internal systems
0.01 0.0005
0.1323 1.37 x 10
-6
3.36 x 10
-6
1.68 x 10
-7
3.36 x 10
-4
1.68 x 10
-5
Total 0.134 0.00052
Tolerable NG Safety
Input parameter Symbol Value
Ground flash density 16.8
Number of over voltages [1/year]
2.709 x 10
-3
0
13.227
3.36 x 10
-4
3.36 x 10
-2
Structure dimensions [m] L, W, H 0.95, 0.95, 3.177
Location factor of structure 0.5