Engineering

SAFETY DEVICES FOR REPAIR OF ELECTRICAL EQUIPMENT

The safety devices and tools used for repair of electrical equipment should comply with requirements in respect of dielectric strength, insulation resistance, mechanical strength etc. The insulating gloves, gauntlets, mats shoes, helmets, and insulated tools should be periodically tested and worn out safety devices should not be used. Rubber devices should not be used on circuits in excess of 3000 volt rating.

Insulating mats are used so that if a person touches a live part accidentally he will not receive shock. Conducting mats are used to discharge electrostatic charges induced during work at places like hospital operation theaters and where explosive are processed. The conducting mates are connected to earth. The insulating mats and the conducting mats should be labelled and used for the appropriate application.

The use for repair of electrical equipment should be confirmed for the following devices and tools:-

1. Rubber Safety Devices

All rubber protective equipment should be inspected before use, thoroughly dried before being stored, protected from mechanical damage and from contact with oil, paint, creosote, gasoline, kerosene and acids; stored in close boxes and never be stored in sharply folded condition.

2. Rubber Gloves and Gantlets

Rubber gloves and gantlets are used with operating rods of HT and EHT Switch gear. Leather gloves can be worn over rubber gloves where necessary for mechanical protection of the rubber gloves. The right hand glove wears out earlier than the left hand glove. Then the left glove should not be worn on right hand. The rubber gloves should be periodically tested for dielectric strength at 10 kV.

3. Ladders and other Supports Should not be Used

Unless the support is adequately strong and properly secured in places. Safety hooks or shoes should be provided for ladders. Ladders should not be left leaning against a tree or placed upon a box, barrel or other moveable insecure object. They should be stored upon brackets and in sheltered location, preferably hung vertically. Where they have to be inevitably stored in horizontal position, they should be properly supported at intervals to prevent sagging. The angle should not be less than 75° while using. A ladder should not be placed in front of doors and windows opening towards the ladder unless the doors and windows are locked. While going up or down a ladder the person should always face the ladder and use both the hands.

4. Safety Belts

 Safety belts should be made of leather suitable for fastening around the waist and straps or pockets may be provided for carrying tools. Safety belts should be inspected periodically and before wearing for the condition of leather near holes, rivets, stitches, buckles, rings, straps etc. They must be kept pliable by treating them occasionally with suitable oil like castor oil. Belts should be prevented from cuts and abrasions during storage and use and not be stored with hardware or sharp objects.

Safety belts should be wiped with clean linen after exposure to rain and be allowed to dry at ambient temperature and should not be exposed to heat.

5. Fibre Ropes

Fibre ropes are made of manila fibre, sisal fibre and hemp should be inspected frequently. Interior fibres may appear strong. After a certain period of use fibre ropes should be derated and after a further period they must be discarded irrespective of appearance. Ropes should not be handled roughly by puling over rough surfaces. When ropes  have to be run inevitably over sharp bends soft padding by gunny bags wrapped around the  edge may be provided and the rope should be passed over the same. Kinking should be avoid. Wet rope should first be dried and then stored in coils. While using ropes they should not be overloaded.

6. Wire Ropes

Wire ropes should not be overloaded and while uncoiling kinks be avoided. Coiling should be done in correct direction to avoid twist. Wire rope should be cleaned and lubricated at regular intervals to avoid excessive wear from abrasion and to avoid erosion and rusting short bends should be avoided. Sheaves of sufficient diameter and correct groove size should be used.

7. Chains

Chains should never be overloaded. Knots should be removed before loading. Sudden or abrupt application of loads should be avoided. Chains which are used for hauling should not be used for lifting.

Chains should be repaired only be approved methods.

Chains should be regularly inspected for wear, damage, battered or bent links, stretch and open welds. Repaired chains should not be used for hoisting or heavy hauling. Chains should be cleaned regularly to avoided excessive wear at interlink points. Before storing for long periods chains should be thoroughly cleaned and lubricated.

8. Slings

All slings should be carefully inspected before using each day. All users should familiarize themselves with the use if slings with respect to size and safe loads for various loading angles. Slings should never be used at an angles less than 30° to the horizontal. Load must be evenly distributed when multiple slings are used and care should be exercised never to overload slings. Multiple slings should be of equal cross section. Slings should not be placed around sharp edges of loads unless adequate padding is placed to provide damage to the sling.

About the author

Thalib Tantary

My name is Thalib Mushtaq Tantary and i am the founder of this very site. I am a medical or civil engineering student and i love to help people get out of trouble they counter in their lives.
Since most often students find it difficult to understand their text books or even there many who can not afford such books, therefore we prepared ourselves to solve this problem faced by them.

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