A SHORT GUIDE TO CONSTRUCTION SAFETY (WITH CHECKLIST)

 CONSTRUCTION SAFETY

Minimum Requirements for Safety

 Personnel are to be aware of what is required of them

 Areas of responsibility are defined and lines of communication are clear

 People take that responsibility seriously and take the appropriate action when they see or foresee a problem

 Be familiar with codes of practices and be able to implement them

 Review internal procedures (i.e. check lists) and use them

 Don’t allow the use of scaffold or scaffolding practices on site that you would not be happy using yourself

 Think Safety and Work Safely

THINK SAFETY

To achieve “zero accident” site, the following precautions and protective equipment are necessary:

Personal Protective and Life Saving Equipment

Personal protective equipment (PPE) includes articles such as eye, face, head and extremity protection; protective clothing; respiratory devices; protective shields; and barriers for mechanical, chemical, or other workplace environmental hazards. 

Head protection: Protective helmets (hard hats) must be worn by employees who work in areas where there is a possibility of head injury from impact, falling or flying objects, or electricity.

Hearing protection: Hearing protection must be worn when noise levels cannot be reduced by engineering or other means.

Eye and face protection: Eye and face protection must be used to protect against physical, or chemical agents. Protection must be reasonably comfortable, fit snugly, and not unduly interfere with employee movement. Employees whose vision requires the use of spectacles, shall be protected by goggles

Use eye goggles/ protective cover on face while hacking, welding, glass cutting, chipping or drilling operations

Respiratory protection: Construction sites must have a written plan for procedures to select and use respirators. Respirators must be regularly cleaned and disinfected, stored properly, and inspected. Users must be properly trained in selection, use, and maintenance of respirators. 

Safety belts and lifelines: If safety belts, lifelines, and lanyards have been used for in-service loading, they must immediately be removed for service in employee safeguarding. Ensure that these personnel at all times are secured to the building.

Safety nets: Safety nets must be provided if workplaces are higher than 25 feet above the surface and ladders, scaffolds or other safety equipment is impractical. 

Workers over or near water: Life jackets or buoyant work vests must be provided to employees where the danger of drowning exists. These must be inspected for defects before and after each use. 

 Workers below 18 years of age should not be allowed to work at site

 When workers on the construction site are exposed to vertical drops of 6 feet or more, provide fall protection in one of three ways before work begins: 

 Placing guardrails around the hazard area. 

 Deploying safety nets

 Providing personal fall arrest systems for each employee. The belts should be always tied above the person. 

 Openings in the slab should be barricaded/closed at all levels. For high rise building use safety nets at appropriate locations. Clear the debris fallen on the net once in 2 days. Also, tighten the net, once in a fortnight.

 Do not allow work in vertical alignment at edges, stairwell, lift well or other openings in the slab without close supervision

 Secure working platform planks with ropes to the scaffolding. The thickness of the working platform if in wood, should not be less than 2”. Check the planks for splits.

 Place scaffolding on firm even ground and check periodically (twice a week). Get the scaffolding checked for potentially weaker zones and horizontal bracing. Supports through toilet ventilators get inadvertently removed while tiling and do not get replaced.

 Dowel rods should not be left naked at the body level. It is good practice to cover them with thick hessain cloth and POP.

 TRENCHES

Trenches 5 feet deep or greater require a protective system. Trenches 20 feet deep or greater require that a registered professional engineer design the protective system.

Protective Systems for Trenches

 Sloping protects workers by cutting back the trench wall at an angle inclined away from the excavation.

 Shoring protects workers by installing wooden, aluminum, hydraulic or other types of supports to prevent soil movement.

 Shielding protects workers by using trench boxes or other types of supports to prevent soil cave-ins.

Safety Instructions

 Inspect trenches at the start of each shift, following a rainstorm or after any other hazardous event.

 Test for low oxygen, hazardous fumes and toxic gases before entering a trench.

 Keep heavy equipment and excavation spoils at least two feet away from the trench edge.

 Provide stairways, ladders, ramps or other safe means of access in all trenches 4 feet or deeper.

 Use strong and well-secured ladders for access. Maintain ladders free of oil, grease and other slipping hazards. Tie the top end of the ladder securely.

 Use industrial safety pin & plugs. Use insulated & safely secured electrical conduits for transmission

 Periodically test the lifting machinery such as cranes and hoists, and lifting gear such as ropes and shackles.

 Inspection and rectification of access facilities such as scaffolds and ladders

 Provide adequate artificial lighting wherever natural light is inadequate

 Provide appropriate fire fighting equipment at potentially hazardous locations. Check fire-fighting equipment for date of expiry and ensure that all are conversant to use them.

 Remove wooden shavings from carpentry yard every day.

 Use face mask, hand gloves & eye protection while handling chemicals

 Take measures to control the menace of mosquito, flies, rodents, snakes, termites, bees etc. 

 Keep first aid kit and snake bite kit in the site for emergencies and train as many people as possible to use them.

 Avoid lady workers working in potentially dangerous locations like sloping roofs.

 Safety training and education

 Conduct mock emergency drill once in a month to streamline the systems of fire fighting, attending a minor injury, or taking a person with serious injury to the nearest hospital. 

 Educate workers on safe work practices on a regular basis. Emergency escape procedures, evaluation plans and emergency escape route shall be well-defined

 Keep a uniform pace of work and train workers to be always on alert

 Names of persons or departments who can be contacted in case of emergencies should be displayed.

 Use adequate safety signs around the site to warn workers of potential danger

 Water sources like sumps to be covered or barricaded.

 Good housekeeping of materials through proper method of stacking avoids accidents.

HOUSEKEEPING

 Provide dustbin in common areas.

 Clean debris accumulated regularly. Keep the site clean at all times.

 Provide dust bins of capacity 150 litres per 5000sft of built up area

 Collect debris at a common point (debris yard) that is easily accessible to a tractor cum trailer. Shift the debris on a daily basis

 Stack materials required at site neatly, and away from heavy traffic areas

 Dedicate a team for house keeping and supervise their works on a daily basis. After structure is completed, allocate one person per 20,000 Sft of floor area for house keeping. During the construction of structure allocate one person per 30,000 Sft of floor area for the same purpose.

 Preliminary cleaning is to be done by the concerned contractor/tradesman. The housekeeping squad should do the general cleaning and carting of debris.

 Stack granite slabs properly on level ground using MS stands to maintain balance on both sides.

 Provide temporary doors with locks at entrances of apartments to reduce the area of liability for cleaning

 In apartments, the sand shifted for masonry/ Plastering or filling should be stacked in a remote corner of the room with blocks circumventing the edges. The spreading of sand due to human movement is avoided.

 Smoking, chewing tobacco is strictly prohibited at site.

 Impose heavy penalty as a deterrent if the person is found littering, doing nuisance at site or not observing safety regulations.

INSPECTION METHODOLOGY FOR QUALITY ASSURANCE

ENSURE

A. Personnel

a) Wearing of safety helmets absolutely mandatory. Ensure entire construction site is hard-hatted

b) Safety/ warning boards at vantage points to ensure the above

c) Wearing of safety belts is compulsory.

d) Wearing of safety goggles and ear plugs for people working on shearing/ grinding machines

e) Wearing of gloves for all dangerous activities

f) Wearing of gum boots during concreting

g) Provision of stretcher and first aid kit on each site (for emergencies)Barricading

a) Trenches are barricaded at 1m from the edge and to a height of 1m

b) All staircases must be barricaded

c) All lift shafts must be barricaded immediately after deshuttering

d) Solid barricading in necessary areas with tape barricading done in additional areas

Lighting

a) Entire site should be floodlit with halogen lamps

b) Lighting on top priority on all staircase areas

c) Lighting of all cellars

d) Lighting in all material storage areas except where diesel and petrol is stored

Fire extinguishers

a) Fire extinguishers provided in

 Site office

 Diesel & Petrol (POL) storage areas

 Store for Wooden items/ Carpentry yard

 Paint storage areas

b) Instruction manual of fire extinguishers on-site

c) Training of Project manager and at least 5 site supervisory personnel by suppliers

d) Expiry date of fire extinguishers and regular inspection to form a part of the Annual Maintenance Contract (AMC) 

Cleanliness on site

a) Access roads to site and office always to be maintained free

b) Stack all materials to a height of 1.5m only

c) Stack cement bags up to 10 bags high only

d) Stack all H-frames cleanly

e) Clear all debris and debris yard at regular intervals

f) Introduction of visible safety/ warning boards on site, such as below:

Check points with the Project Manager  

a) Personnel working on grinding machines should use proper safety gear. 

b) Operations of electric saw cum planing machines should be protected sufficiently. Most electric saws’ are delivered along with the planing devices. It is noticed that when the saw is in action, the planing devices are open and vice versa. This poses extreme danger to all operations. Therefore, the following guidelines should be adhered to:

 Proper wooden/ metal cover to the saw blade at all times

 Proper cover to planing device

 When not in use, the cutting devices should be covered after duly cleaning them 

c) Provision of one fire extinguisher is essential

CONSTRUCTION SAFETY & HOUSEKEEPING CHECKLISTS  (Download)

 

PLUMBING WORKS IN BUILDINGS - METHODOLOGY & CHECKLIST

 PLUMBING WORKS

 A. INTERNAL WORKS - Water Lines

1. Internal pipe work in Toilets and Kitchen to be concealed and carried out as per working drawings.

2. As per the heights mentioned in plumbing drawings, mark the line on walls by chalk in proper alignment and plumb

3. Start chasing of line using a chasing machine or chisel and hammer. The chasing should be done keeping the following points in mind.

 Depth - Should not be more than pipe size

 Width - Sufficient to accommodate the pipe line

 Alignment - Straightness should be considered

 Height - For all fittings height as given in Drawing

5. Check Class / Specifications of Materials.

 High Pressure threaded Blue UPVC Pipes of Schedule 80 to be used for cold water pipes made of ASTM IS-1785 and threaded as per IS 1239 (Part I)

 Class 1 Copper pipes as per BS 2871 Part 1 and fittings as BS 864 Part II should be used for Hot Water.

 G.I Fittings should be used for cold water – pipe work as per IS 1239 (Part II)

6. Prepare pipe-skeleton and check all joints for proper tightness. Only approved make pipes, pipe fittings and accessories including jointing materials should be used

7. Groove chasing should not exceed 30 mm after rough plaster for cold water supply line and cold feed line and 50 mm for hot water supply lines.

8. While threading UPVC pipe at site, ensure square cut of pipe ends, chamfer the ends with a file, insert proper size wooden plug in the pipe end and then carryout threading. The sharp edges of gripping vice and other handling tools should be muffed with a suitable packing to prevent damage of pipe surface.

9. The joints should be made with hand tightening of the fitting over pipe and covered with proper layer of Teflon tape. To make the joint permanent, one to two turns over the hand tightened joint is sufficient. Avoid over tightening as this may damage both the pipe and fittings.

10. Special care should be taken while connecting UPVC pipe with G.I Fittings. High quality shellac should be used for jointing.

11. Water tightness of line to be checked using pressure testing equipment. All other openings should be plugged except end portions to which pressure gauge machine is connected.

12. The pressure reading should be above 7 kg/cm2 (80 PSI); and there should not be even a single drop of water coming out of the joints during testing. The duration of the test is 24 hours.

13. Apply bitumen paint over the G.I pipe work.

14. All the bore pieces projecting out should be minimum 200 mm from plastered surface.

15. Cover the skeleton including fittings with good quality Hessian cloth and tie it properly for cold water pipe work.

16. Fix the skeleton in wall using 40 mm plumbing nails at a distance of 230 mm on alternate side.

17. Do the pressure testing once more after fixing in position and ensure no leakage.

18. Keep a gap of 10 mm between all pipes and fittings to accommodate thermal expansion and contraction of pipes for longer life of the system.

19. Horizontal lines within bathrooms should be cement encased and tested before compacting of sunken floor to avoid any accidental damages.

20. Curing should be done over the plaster for at least 7 days.

Installation Guide For Copper Pipes (Hot Water Lines)

1. Make sure that you have the correct size fittings and tube.

2. Prepare the end of the tube by cutting to the correct length with a tube cutter or fine bladed hacksaw. The ends of the tube must be cut square to the axis and be especially careful not to damage the ends of the tube. After cutting the tube, you will notice some rough edges around the outside and inside of the tube. This is called burr and should be removed with a file or sharp blade.

3. Clean the outside surface of the tube that will eventually go into the socket of the fitting, along with the inside surface of the fitting. 

4. Apply water soluble flux to the tube and fitting by smearing a thin film of FLOWFLEX Flux around the outer ends of the tube that have been cleaned and to the inside of the cleaned socket of the fitting. This is best done with a small brush to avoid applying too much and to prevent contact with the skin. 

5. Insert the tube into the fitting and push home until the stop is reached and wipe off any excess flux with a clean cloth.

 For Integral Solder Ring Fittings (Inbuilt):

6. Apply heat to the assemble joints to be made using a conventional blow Lamp torch or similar appliance that emits flame that is clean, blue and soot-free. Once a complete ring of solder has appeared around the mouth of the fitting, turn off the heat. The complete silver coloured ring of solder is proof of a sound joint.

 For End feed Fittings:

7. Apply the flame to the fitting to heat tube and solder cup of fitting until solder melts when placed at the joint of tube and fitting. Allow the joint to cool without disturbance. 

8. Remove the flame and feed solder into the joint at one or two points until a ring of solder appears at the end of the fitting. The correct amount of solder is approximately equal to 1 ½ the diameter of the fitting ¾” long solder for 15mm fitting etc. 

9. Wipe off any excess flux and residues, with wiping cloth after the joints cooled

B. INTERNAL WORKS - UPVC TRAPS

INSTALLATION:

1. Determine correct location of ‘P’/ ’Q’/ ‘S’ Traps and set it on a firm base located relative to the floor finish by pouring concrete on a slab.   

2. Bedding can be carried out by pouring concrete around ‘P’/ ’Q’/ ‘S’ Trap; ensuring that outlet of Trap is left clear on concrete.

3. Apply rubber lubricant on W.C. connector ring as well as on outer side of WC pan 

4. The outlet can be inserted in the socket end of pipe / fittings (as the case may be) and joint can be solvent cemented to make a leak proof joint. 

JOINTING INSTRUCTIONS

1. Make sure the spigot end and inside of the socket is clean and the sealing ring is placed evenly in the socket. 

2. When cutting pipes, make sure they are cut square. Chamfer the end cut to an angle of 15 0 with a medium file. Cutting of pipes should be straight, as diagonal cutting leads to leakages

3. A correct depth of entry of the spigot into the socket is required to allow thermal movement. To achieve this, push spigot fully into the socket (remove sealing ring at this time) and make a mark on the spigot. Withdraw the spigot by 10 mm & mark the spigot with the bold line. This bold mark indicates the correct depth of entry to allow the necessary expansion gap.

4. Smear rubber lubricant evenly on the chamfered spigot and the sealing ring. Then insert the spigot into socket with light twisting motion. Pull out the pipe to allow 10 mm expansion gap.

5. Maximum Support Distance In Meter:

Size in mm	40	50	75	110	160
Horizontal	0.4	0.5	0.75	1.1	1.6
Vertical	1.2	1.5	2.00	2.00	2.00

C. EXTERNAL PIPE WORK

1. Spacing of inspection chambers and manholes should be such that cleaning of sewer lines can be done easily.

2. Inlets and outlets of chambers and manholes are to be plugged during progress of the work. It should remain plugged till completion of the sewer lines up to disposal so as to avoid blockage / choke-up of sewer pipeline.

3. Ensure gully’s/channels of inspection chambers/manholes have given a smooth curve if sewer lines are intersecting at right angles.

4. Bottom of gully’s/channels should be laid in slope at inlet to outlet of chambers and should be finished smooth.

5. All sewer pipes, traps and other fittings should be free from cracks, holes and burrs etc., and to be checked before being put into use.

6. Outflow of chamber should have 25 mm (1”) drop than in flow of chamber.

7. Joints of sewer pipes to be plugged with cotton yarn (packing rassi) before applying cement slurry over joints.

8. Heavy-duty chamber covers are to be used in parking and on road whereas light duty covers may be used for other places. The covers used in manholes in sewer lines shall invariably bear the word, ‘SEWER’ on the top and those used for storm water drains shall bear the word ‘STORM’.

D. SOIL WASTE & RAIN WATER (S.W.R) DRAINAGE SYSTEM

JOINING INSTRUCTIONS:

1. Use only rubber lubricant for joining SWR pipes & fittings, where rubber ring is used. 

2. Avoid misalignment of vertical SWR pipe stacks and incorrect spacing of pipe clips.

3. All entry to main stacks should be protected with water seal trap, wherever there is mixing of soil & waste lines.

4. Keep a gap of 10 mm between all UV stabilized SWR pipes and fittings to accommodate thermal expansion and contraction of pipes for longer life of the system.

5. Smoke test should be avoided and test plug / socket plug should be used for testing the lines.

6. Horizontal lines within bathrooms should be cement encased and tested before compacting of sunken floors to avoid any accidental damages.

7. When cutting pipes make sure they are cut square. Chamfer the end cut to an angle of 150 with a medium file.

8. A correct depth of entry of the spigot into the socket is required to allow the thermal movement. To achieve this, push spigot fully into the socket (remove sealing ring at this time) and make a mark on the spigot. Withdraw the spigot by 10 mm & mark the spigot with a bold line. This bold mark indicates the correct depth of entry to allow the necessary expansion gap.

9. Smear rubber lubricant evenly on the chamfered spigot and the sealing ring. Then insert the spigot into socket with light twisting motion. Pull out the pipe to allow 10 mm expansion gap.

10. Tubes installed underground, laid on floors or in other inaccessible places must be able to withstand twice the maximum working pressure.

11. While laying big pipelines provision should be made for expansion joints, air vents and proper anchorage. In case of longer runs provide air valves at all higher points of ground and the size of the valves should be ¼th of the main line.

12. For large diameter and higher class pipes (6 kg / cm2 and above) always use heavy-duty solvent cement. Within 24 hours, the rigid PVC pipes are ready for use.

TESTING NON-PRESSURE INSTALLATION ABOVE GROUND      

The SWR drainage system can be put to use immediately after installation, as no waiting time is required for joints to be set and dried. However for testing, seal hermetically all openings below the top of the section to be tested. The water level shall then be raised to a height of not less than 3 meter above the highest point of the section being tested. Every joint shall be carefully examined for leaks

E. DUCT & HIGH LEVEL PIPEWORK

1. Pipe work in ducts and voids shall be supported from specially designed mild steel brackets and cantilevers with swinging hangers. Roller type supports and ‘U’ bolt clips shall be used.

2. The brackets shall be provided and fixed to the sidewalls, beams and ceilings, where a bracket or support carries more than one pipe of different sizes, the spacing of the brackets or supports shall be that specified for the smallest size of pipe.

3. All pipes must be kept at least 150 mm from lighting and power cables or conduits.

4. Pipes shall be spaced in ducts and below floors in a manner, which will permit subsequent access to any pipe for maintenance or removal without disturbance to the remaining pipes.

5. All piping shall be grouped wherever practical and shall be erected to present a neat appearance. Pipes shall be parallel to each other and fixed at right angles to structural members and shall give maximum possible headroom. All pipe drops shall be truly vertical.

6. All pipes must be supported in such a manner so as to allow free movement for expansion and contraction and graded to the required levels for air elimination and drainage.

F. RETICULATED LPG SYSTEM

1. The Gas Cylinder bank provided, is equipped with a manifold to which the cylinders are connected. Each point of connection of the cylinder to the manifold has got a Non Return Valve to take care of any emergency arising out of failure of the Cylinder Pigtail.

2. To take care of excess Pressure build up in the pipeline after the regulator, an Over Pressure Shut Off system coupled with the Regulator is provided.

3. As far as the pipeline is concerned, there will be no threaded joints in the pipeline. The pipeline would be necessarily DC Socket welded and hydro tested in line with the code requirement.

4. Moreover, leak detectors may also be installed in the Gas Cylinder bank, which would give an audiovisual indication once the LPG level in the enclosure increases beyond safe limits.

TOOLS TO BE USED BY TRADESMEN

Required tools must be available at site to ensure correct work. Basic tools of the plumbing gang are:

1. Chisel

2. Pipe Wrench

3. Chain Wrench

4. Sledge Hammer

5. Screw Driver

6. Bench Vice 

7. Pipe Vice

8. Die Set

9. Hammer Drilling M/C

10. Mini Angle Grinding M/C

11. Drill

12. Chasing Machine

13. Spirit Level

14. Hammer Drill Bit

15. Grinding Wheel

16. File

17. Measuring Tape

18. Pressure Testing Machine

 

  INSPECTION METHODOLOGY FOR QUALITY ASSURANCE

1. Check the direction of flow vis-à-vis the installation of pipes

2. The water has to flow into the sleeve. Check for leakage and subsequently establish whether due to faculty sealing [Insufficient application of adhesive]

3. Check for slopes installed using spirit levels

4. Ensure all joints are waterproofed to ensure leak proof pipes  

TOOLS TO BE USED FOR QUALITY INSPECTION

1. Spirit levels

2. Plumb bob

3. Measuring tape

4. Related “Good for Construction” service drawings

CHECKLIST FOR PLUMBING WORKS (Download)

ELECTRICAL WORKS IN BUILDINGS - METHODOLOGY & CHECKLIST

 ELECTRICAL WORKS

A. METHOD OF CONDUITING, BOX FIXING & INTERNAL WIRING

1. Carry out the work as per the latest approved drawings confirmed by the concerned Project Engineer. All electrical conductors shall be of sufficient size and current rating for the purposes for which they are to be used.

2. Use medium /heavy gauge rigid PVC Conduit: 20 /25 /32 mm diameter, 2mm thick black colour and of ISI approved make, as indicated in drawing. 

3. Conduits should be laid between the reinforcement of slab and properly fastened to the reinforcement with binding wires.

4. Care should be taken to see that the conduits are held in position and the cement grout does not enter the conduits while concreting and no conduits get damaged due to movement of laborers on the slab before pouring and during pouring for inspection of conduits & joints. For the floor conduiting care should be taken that conduiting is done only just before the flooring works starts.

5. Vertical conduits in wall chase to be properly fixed in position at the location indicated in the drawing. Horizontal runs of conduits in wall to be avoided as far as possible. In hollow blocks, horizontal chases are not permitted.

6. Bends in conduit pipes should not be sharp. In embedded conduiting bends made with bending spring with large radius should be used. The maximum bending radius allowed in any conduit is 2.5 times the diameter of the conduit.  The use of readymade bends should be avoided as far as possible.

7. Switch boxes to be recessed in the wall in such a way that it should be projecting 1-3 mm from wall plaster. The thickness of plaster shall be ascertained with button or bull marks and confirmed by site engineer. The boxes may project a maximum of 1-3 mm. Further, the wall finish such as lime rendering or punning, Glazed Tiles / Marble / Granite, etc. are to be confirmed with concerned Project Engineer. The finish will determine the projection. The idea is to ensure the box projects 0.5mm beyond the painted surface and the edges do not break while the wire is drawn.

8. Cover all the boxes with thermocol and masking tape / dummy plates to avoid damages during plastering. These covers should be removed only at the time of wiring.

9. Pass GI pull wires of 16-gauge inside the conduits with additional loop length of 15cm as draw wire.  

10. The wiring cables to be of ISI approved make, PVC insulated, stranded copper and 1100V grade. Use following cross section for wiring.

6 Sqmm         - Sub mains (or as per drawing)

4 Sqmm - Power Circuit

2.5 Sqmm - Lighting Circuit 

        Earthing for Sub mains

               1.5 Sqmm - Light point wiring, 5A socket outlets & fan circuits

          Earthing for Power Circuits

                1 Sqmm         - Earthing for light point wiring, 5A socket outlets & Fan Circuits.

11. Red, Yellow, and Blue for phases, Black for Neutral and Green for earth – colour coding for wires must be followed.

12. Expansion coupler shall be used when conduit passes through building expansion joint. One end of the expansion coupler shall not be glued.

13. Earthing

At every light point earthing terminal should be provided and connected to the earth continuity conductor. The resistance of any point of the earth continuity system to the main earth electrode should not be more than 0.5 ohm.

Every electrical circuit and sub-circuit shall be protected against excess current by circuit breakers. No circuit breaker other than a linked circuit breaker shall be inserted in a conductor connected with earth.

Where metal works other than current carrying conductors is liable to become charged with electricity, the metal works shall be earthed in such a manner as to ensure immediate electrical discharge without danger. The neutral conductor shall be insulated throughout and at no point it should be connected to the earthing system.

All earth connections shall be visible for inspection and shall be carefully made; if they are poorly made or inadequate for the purpose for which they are intended, loss of life and property or serious personal injury may result.

Joints in the earthing should be invariably done by means of welding except in such locations where intermittent disconnection of joints is necessitated for testing purpose or for the earthing connection to the body of the equipment etc.

Use fully insulated tools while handling electric wires and equipment.

14. Mounting Height of Electrical Accessories

Light switch - 1250 mm above Finished Floor Level (F.F.L.)

Bell Push - 1250 mm above Finished Floor Level (F.F.L.)

Socket Outlet - 300 mm above Finished Floor Level (F.F.L.)

TV/Telephone Outlets - 300 mm above Finished Floor Level (F.F.L.)

Bedside Accessories - 600 mm above Finished Floor Level (F.F.L.)

Socket Outlets in the Kitchen- 1140 mm above Finished Floor Level (F.F.L.) and (+300mm from Counter Top)

Cooker Control unit 1140 mm above Finished Floor Level (F.F.L.) and (+300mm from Counter Top)

Wall Lights - 2200 mm above Finished Floor Level (F.F.L.)

15 A in Utility for Washing Machine 900 mm above Finished Floor Level (F.F.L.)

Connection Unit for Exhaust Fan 2300 mm above Finished Floor Level (F.F.L.)

EXTERNAL CABLE LAYING

Cable laying involves two steps

 Trenching.

 Cable Pulling / Laying.

TRENCHING

Trenches are dug as per requirement of cable sizes and other atmospheric conditions before digging route has to be finalized. The areas to be avoided for cable laying are near sewage line, Ground-containing ashes, Slag, Clinker, Fertilized Solid & Electrolytic Corrosion, which will affect the life of cables.

Standard Depth of Trenches:

 Up to 1.1 KV = 450 to 750mm.

 Up to 11KV   =750 to 900mm.

CABLE LAYING

Before laying the direction in which the cable is to be pulled should first be decided. If it is a new cable no special precautions are necessary, but if it is laying parallel to the existing cable, the core sequence to be synchronized. Pulling force for Copper & Aluminium cables with steel tape armour when pulled is as follows:

 Copper - 7 Kg /Sqmm of total conductor area

 Aluminium      - 2 Kg /sqmm of total conductor area

Also bending radius should be taken in to consideration.

Rating	Single-Core Unarmoured	Multi-Core armoured
Up to 11KV	15 D	12 D
Up to 22KV	20 D	15 D
Up to 33KV	25 D	20 D

D - Overall diameter of the cable

Where the cables have to be laid below ground level a trench shall be made and a layer of sand be provided at the bottom for the cable to lie on. One more layer is provided after laying the cable and a cable marking tape should be provided over it before doing the back filling.

A minimum horizontal clearance of 150mm should be provided between the cables whenever number of cables is more than one. Where cables pass through holes or metal works precaution shall be taken to prevent abrasions of the cables on any sharp edges.

High Voltage HV/ Extra High Voltage EHV DISTANCE CLEARANCE: 

It is desirable that Extra High Voltage (EHV) lines do not pass above or adjacent to any building or part of building. If this cannot be avoided, it shall have on the basis of maximum sag, vertical clearance of not less than 

For HV line up to and including 33 KV - 3.7m

For EHV lines - 3.7+0.3m for every additional 33 KV 

The horizontal clearances between the nearest conductor and any part of such building shall on the basis of maximum deflection due to wind pressure be not less than …

For HV lines up to and including 11 KV - 1.2m

For HV lines above 11 KV and up to 33 KV - 2.0m

For EHV lines - 2.0 + 0.3m for every additional 33 KV or

TEMPORARY INSTALLATIONS ON BUILDING SITES

For temporary electricity supplies, voltage operated Earth Leakage Circuit Breaker shall be installed. Only double insulated cables and industrial type weatherproof socket outlets should be used for the distribution of temporary power.

  

TOOLS TO BE USED BY TRADESMEN

Required tools must be available at site to ensure correct work. Basic tools of the electrical personnel:

I	Hand Tools
1	Screw Drivers - Flat	Small, Medium & Heavy Duty
2	Screw Drivers - Star	Small, Medium & Heavy Duty
3	Cutting Pliers	Small, Medium & Heavy Duty
4	Nose Pliers
5	Wire Stripper
6	Line Tester
7	Hammer	Small, Medium & Heavy Duty
8	Chisel
9	File	Rough, Smooth
10	Hacksaw Frame
11	Hacksaw Blade	Ordinary, High Speed
12	Ring Spanner Set
13	Box Spanner set
14	Metal Tool Box
15	Crimping Tools	Small, Medium & Heavy Duty
16	Telephone Crimping tool
17	Hole saw Cutter
18	Bending Spring	20 mm & 25 mm
19	Curtain Spring
20	Line Dori
21	Blow Lamp
II	Power Tools
1	Hammer Drilling Machine
2	Air Blowing Machine
3	Angle Grinding Machine
4	Mini Drilling Machine
5	Hammer Drill Bits	Different Sizes
6	DC Segmented/Non-Segmented Blades
III	Measuring Instruments
1	Multimeter
2	Digital Clamp Meter (Tong Tester)
3	Megger
4	Earth Resistance Tester
5	Lux Meter
6	Measuring Tapes	Different Lengths
7	Spirit Level	Different Lengths

INSPECTION METHODOLOGY FOR QUALITY ASSURANCE

Ensure:

1. All junction boxes, fan boxes, and drop points pertain to drawing location

2. Check Inner diameter, wall thickness and allowable tolerance for conduits has to be done by means of Slide Caliper.

3. Binding of all conduits to steel done properly before slab concreting

4. Solvent cement for all joints applied properly

5. All openings/ open ends are sealed

6. Conduits running parallelly are not touching each other i.e. there are no voids in the concrete

7. Test lamp method – ensure that all electrical points are charged

8. Check of ELCB (Earth Leakage Circuit Breaker)/ Residual Current Circuit Breaker by random trip of electrical circuit

9. Check with multimeter -  

 Phase to neutral – 230V

 Neutral to earth – less than 2V

 Phase to Earth – 230V

10. In contractual projects where lighting fixtures are part of the scope of work, check the illumination levels with a Lux meter to conform to client specifications

11. Electrical switch plates should be flush with finished wall level

TOOLS TO BE USED FOR QUALITY INSPECTION

1. Multimeter

2. Lux meter

3. Test lamps

4. Vernier Calipers

5. Spirit levels 1-2m

6. Measuring tape

ELECTRICAL WORKS CHECKLIST (DOWNLOAD)