NOISE ASSESSMENT FOR SUBSTATION PREVENTIVE MAINTENANCE AND OIL CABLE

MAINTENANCE

Hisham GhunaimOccupational Health and Safety

Specialist

Photo of Speaker/Author

Content

• Introduction

• METHODS AND DATA COLLECTION

• RESULTS AND DISCUSSION

• Recommendations and Noise Control

Introduction

• Substation Preventive Maintenance activities:

• Switching Operations at Jabriya-Z 400 kV Substation

• SF6 Gas handling SLWT- A 132 kV Substation

• Oil Cable Maintenance activities:

• Oil Flushing at Salwa B 132 kV substation and

University A 132 kV substation

Introduction

• Substation Preventive Maintenance Health risk,

affected people & noise exposure sources:

• Employees exposed to breaker maintenance

& spring charging operation activities

(switching operations)

• Employees exposed to SF6 gas handling

machine

Introduction

• Employees exposed to SF6 gas handling machine

Introduction

• Oil Cable Maintenance:

• Employees exposed to degasifying unit that

include degasifying unit pump & vacuum

Vacuum

Pump

METHODS AND DATA COLLECTION

𝐋𝑬𝑷,8 = 10 𝑳𝒐𝒈10

σ𝒊=1𝒏 ቀ𝒕𝒊 × 100.1 (𝑳𝑨𝒆𝒒,𝑻)𝐢

8

L𝐸𝑃,8 is the equivalent sound exposure level in 8 hours;

i is a discrete activity of a worker exposed to a sound level;

ti is the duration in hours of i;

(𝑳𝑨𝒆𝒒, 𝑻)𝐢 is the equivalent continuous A-weighted sound pressure level that represents

the sound the person is exposed to during period i

n is the total number of discrete activities in the worker’s total workday

METHODS AND DATA COLLECTION

RESULTS AND DISCUSSIONSwitching Operations

Sound Level Meter Dosimeter

Data Source Lc peak LAeqRecording time (h)

Actual Duration

(h)

Daily Exposure (Lep,d)

Sound Level Meter

125.9 82.6 0.165 0.5 -

Dosimeter 123.3 74.8 1.38 6 73

RESULTS AND DISCUSSIONSwitching Operations

RESULTS AND DISCUSSIONSF6 Gas Machine Handling

Sound Level Meter Dosimeter

RESULTS AND DISCUSSIONSF6 Gas Machine Handling

Data Source Lc peak LAeqRecording time (h)

Actual Duration (h)

Daily Exposure (Lep,d)

Sound Level Meter

106.7 81.4 0.15 5 79

Dosimeter 116.8 81.9 1.27 5 80

RESULTS AND DISCUSSIONOil Cable Maintenance

University A Salwa B

RESULTS AND DISCUSSIONOil Cable Maintenance

Location LAeqRecording time (h)

Actual Duration (h)

Daily Exposure (Lep,d)

University A 73.9 0.91 5 72

Salwa B 78.6 2.28 5 76

Recommendations and Noise Control

Oil Cable Maintenance

• Vibration damping of pumps used in trucks (i.e. degasifying units) to

reduce vibration levels & consequently result with significant noise

reductions.

• Opening both doors instead of one (see Figure 3) in the truck during

operation would significantly reduce the noise level reflection.

Recommendations and Noise Control

Common Controls

• Conduct noise awareness and NIHL training sessions for all working groups with exposure

to identified potential health risks.

• Use of adequate hazard warning signs in high- risk exposure zones.

• Provision and use of suitable hearing protection equipment appropriate to the exposure

level with sufficient attenuation ratings.

Recommendations and Noise Control

Preventive Maintenance

• Minimize personnel exposure at peak operational times by either introducing job

rotations or restriction of access in hazard vicinity zones.

• Regular maintenance of gas handling machines and improving the vibration damping of

pumps.

Acknowledgements

The author sincerely acknowledges Kuwait ABB Engineering

Technologies Co., represented by Eng. Kareem Gabry (the Country

HSE manager), for all the support and the expertise provided during

the execution of this work. The author would also like to thank Eng.

Adel Younis for the constructive feedback.

Thanks and Questions