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GRANT LAIDLAW
Grant Laidlaw is currently the owner of the Air Conditioning and Refrigeration Academy ( ACRA ) in Edenvale . He holds a Bachelor of Business Administration and an associate degree in educational administration . He has a National Technical Diploma and completed an apprenticeship with Transnet . He has dual-trades status : refrigeration and electrical . He has been involved with SAIRAC for 17 years and has been a Johannesburg committee member for the past eight ( chairman in 2011 and 2012 ). Currently he is the treasurer ( Johannesburg council ) as well as president ( national council ).
ELECTRICAL SAFETY WITH ARC WELDERS
By Grant Laidlaw
All persons who use electric arc welders should have a working knowledge of the electrical hazards that are an inherent part of their job .
QUESTION 1 :
Johann asks : Grant , many refrigeration people work on or near electrical power without any idea to the hazards . I realise that this is the basics , but it should be important . What about electrical safety using arc welders ? Any advice ?
Hi Johann . Many refrigeration people do work with electricity as it forms part of the required skills set . In the last issue of RACA Journal I looked into general safety . Let us now look into the safety aspects when arc welding .
The people using this equipment need to take steps to eliminate and / or mitigate hazards . The following are some of the safety rules and guidelines that apply to welding :
Electric shock is a hazard associated with both electric resistance and electric arc welding . A shock can occur when the equipment isn ' t properly earthed ; through direct contact with energised leads or from contact with the welding leads via moist gloves or clothing ( including damp floors ). Environmental conditions ( such as wet or cramped spaces ) may increase the likelihood of a shock . Even if the shock itself isn ' t too serious , the jolt could cause a possible fall .
Always wear dry , hole-free insulating gloves to protect against or reduce electric shock . The welder should also wear rubber-soled shoes , and use an insulating layer , such as a dry board or a rubber mat for protection on surfaces that can conduct electricity .
Earth the piece being welded . The insulation on electrode holders and electrical cables should be kept dry and in good condition . Do not change electrodes with bare hands , wet gloves or when standing on a wet floor .
In arc welding , the open circuit voltage that exists between the electrode holder and negative during the no load period , presents a potential hazard to the person and those around him . The worker becomes exposed to this voltage when setting up work , changing working position , or changing welding electrodes .
ACRA
The insulation on welding electrode holders is sometimes damaged from rough use and from moving welding equipment through and around tight spaces . Contact with skin or damp clothing by the bare metal exposed when this occurs can result in a shock .
Do not work alone where conditions are especially hazardous , such as where electric shock is a hazard , or where ventilation is poor .
The avoidance of electrical shock is largely within the control of the welder . Therefore , it is especially important that the welder be thoroughly trained on safe welding procedures . Safe procedures must be observed at all times when working with equipment having voltages necessary for arc welding . These voltages can be dangerous to life . Even mild shocks can cause involuntary muscular contractions . Any electric welder , AC or DC , has the power to cause electrocution if the electrode touches your bare skin while you are earthed .
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A coiled extension lead that has melted .
www . hvacronline . co . za RACA Journal I February 2021 41