Electrical inspections are part of factory safety management. The electrical system inspection is responsibility of electrical technicians or engineering staff. This will be in accordance with laws of the Ministry of Industry, conform to the ministerial regulations, prescribing safety measures for electrical systems in factories, B.E. 2550 and according to laws of the Ministry of Labor, conform to the ministerial regulations, the standard for administration Manage and safety, Occupational Health and Environment for Electrical Work, B.E.2558. Generally, electrical inspection and maintenance is an essential part of production system.
What must be checked electrical system?
To make electrical system can be used for long time and reliability. The best electrical system maintenance is preventive maintenance. An important of preventive maintenance is condition monitoring to know about system or equipment has deteriorated or not. Is there condition that needs maintenance? Inspections can be done into 2 types as visual inspection and measuring instruments inspection. Which is requires knowledge to use measurement equipment and analysis as well.
Electrical inspection of Department of Factory to inspect both visual inspection and measuring instruments inspection. The inspection can be done into 2 parts as generally and all of equipment inspection.
This stage is general inspection of the general electrical system it is a simple test. However, Inspector must have good knowledge of electrical hazards and their protection as well. Touching any part must ensure that there is no electricity or has been properly protected. General inspection are as follows:
1) Electrical wires
2) Circuit breaker
3) Connector or connection point
4) Ventilation in electrical room
5) Ventilation and exhaust for generator room
2.Electrical equipment inspection
It is an inspection of electrical equipment to find defects, deterioration, malfunction, etc. Electrical equipment inspection must record results of test and analyze results to find corrective. It is important that some items must be checked while supplying electricity. Some items have to stop the power supply before checking because there is too danger. Person who will checking must have knowledge in this matter as well.
There are several electrical equipment that should be inspected as follows:
Transformer inspection it consists of checking as following,
2.1.1 Transformer body
2.1.2 Metal parts grounding
2.1.4 Warning/Cautions signs
2.1.5 Transformer courtyard area
2.1.6 Transformer poles
2.1.7 Improvements, corrections, additions or maintenance
2.1.8 Check condition of transformer and other installations.
2.2 Main switch
Inspecting the main switch consists of checking as following,
2.2.1 Conditions of grounding system and earthing
2.2.2 The surrounding area of main switch and board must have free space for convenient. Inspection of surrounding area and general condition should check as following;
1) Free area
2) Path to entry free area to perform tasks.
3) Check that combustible materials are placed next to main switch.
4) Dust, rough, around main switch.
2.2.3 Physical abnormalities
2.2.4 Improvements, corrections, additions or maintenance
2.2.5 Other inspections may be additional such as checking the operation of instrument panel, various lamps, etc.
2.3 Panel board
Panel board check is to check whole installation area in general area and flammability area. For flammability area should be specified type of substance also.
2.3.1 Grounding system
2.3.2 Improvement, amendment, addition or maintenance
2.3.3 Other inspections as the same as for main switch.
2.4 Other electrical equipment
Other electrical equipment checks may be only in hazardous areas or storage areas for flammable materials only. When checking must be specified type of equipment. Is it suitable for dangerous area?
2.4.1 Installation area
2.4.2 Equipment and electrical wiring
2.4.4 Improvements, corrections, additions or maintenance
2.4.5 Other inspection is general conditions that can be found from visual inspection such as protection against electrical contact and grounding. Etc.
2.5 Lamps, bulbs and lighting systems
Inspection of lamps, bulbs and lighting systems as following,
2.5.1 Installation and structure of lamp
2.5.2 Lamps and lamp holders
2.5.3 Feeder cables, branch circuits and disconnecting switches of lighting systems
2.5.4 Improvements, corrections, additions or repairs
2.5.5 Other inspection.
3.Frequency of inspection and maintenance
Inspection frequency it depends on environment and usage. Usually, perform once a year consider as following factors:
Atmospheric corrosion, dirt and dust, temperature and humidity, working frequency, Short-circuit cut-off frequency (in case circuit breaker)