INDUSTRIAL INSTALLATION

WHAT IS ESTIMATING? ESTIMATING is an art of assessment of quantities of different items and costs thereof to plan the amount required for executing a work before carrying out the work.

PURPOSE OF ESTIMATING MONEY - To determine necessary amount of money required by the owner to complete the proposed work. QUANTITY – To determine the quantities of materials required in order to program their timely procurement. WORKER – To determine the number of various types of workers required in each work. TOOLS AND PLANTS – To arrange necessary tools and plants as per schedule of work in correct numbers. SCHEDULE – To create a schedule of work. TIME - To calculate the completion time of project.

POINTS TO REMEMBER: Complete specifications of materials. Complete schedule of the points to be wired for with their switches and fittings. Plans and selections marked with details, at least with the position of main switchgear and distribution board. Other information about factors affecting the cost of an estimate.

WHAT IS INDUSTRIAL INSTALLATION? Industrial installation means an installation intended for use in the manufacture or processing of products involving systematic labor or habitual employment and includes installations in which agricultural or other products are habitually or customarily processed or stored for others, either by buying or reselling on a fee basis.

IMPORTANT CONSIDERATIONS REGARDING MOTOR INSTALLATION WIRING. Equipments should be of iron clad construction and wiring shall be of armoure cable or conduit type. Woodwork shall not be used for mounting of switchgear. The length of conduit between terminal bases of motor and starter, switches and motor shall not exceed 1.25 Mtrs. Looping of conductors and use of joints shall not be done. Every motor shall be provided with separate switch fuse placed near it. All motors should be provided with suitable starters. The conduit should preferably be laid in covered trenches. Laying of cables must be in separate conduits for separate motors.

CONSIDERATIONS CONTINUED: Minimum cross section of aluminum conductor : 2.5 mm2 and minimum cross section of copper conductor : 1.25 mm2. The current rating of the cables for supply to motor may be based on normal full load current of the motor but fuse rating should be based on starting current. Conduit used shall be electrically continuous throughout and connected to frame of motor. Wire used to earthing conductor shall be of copper or galvanized iron. Consumer is required to provide his own earthing system with and independent electrode. While dividing the current rating of main switch controlling a group of motors, starting current of one motor plus full load current of remaining motor shall be considered.

QUESTION A 3 phase induction motor of rating 5HP, 50 Hz, 415 V is to be installed in a room of size 5m x 3m x 3.5m high. The motor should be one meter away from the nearest walls. Prepare the list of materials and estimate their cost. Also, draw the installation plan, single line diagram and wiring diagram.

ANSWER Assumptions: 1. Height of main distribution board (MCD) from floor level = 1.5 m. 2. The motor installed on a foundation 0.25 m above floor level. 3. Two number earth wires enclosed in G.I pipe are installed side by side for earthing the motor. 4. Height of horizontal run of conduit pipe below ceiling is 0.5 m.

Calculation of load current. P=√3 VL IL cos φ Taking cos φ = 0.8 and efficiency of motor as 0.85 (85%) the rated current of the 5 HP motor is IL= P   √3 x VL x cos φ x 0.85 = 5x735.5   √3x415x0.8x0.85 = 7.52 Apms say 8 amperes.

Selection of TPIC main switch. The full load current is 8 amperes. Assuming 50% overload i.e. 8x1.5=12.0 amperes the standard size of kit-kat fuse available in the market is 16 amp. Since 16 amperes is very close to the value of 12 amperes the next higher standard size of kit-kat fuse i.e. 32 amperes is selected. So, TPIC main switch of rating 500V, 32 amperes will be used.

WIRING DIAGRAM

Selection of size 3 core cable. PVC cable of size 3 core 4 mm2 , 1/ 2 Selection of size 3 core cable. PVC cable of size 3 core 4 mm2 , 1/ 2.24 mm 660V, will be used which has a current rating of 14 amperes that is more than 12 amps.

INSTALLATION PLAN

Calculation of length of HEAVY GAUGE conduit pipe, 15 mm Diameter. From main distribution board (MBD) to motor foundation =1.5+3+1.5+1.5+0.2+0.5+0.2+0.25 = 8.65 mtrs. 10% wastage = 0.86 mtrs. Total length of conduit required = 9.51 say 10 mtrs.

Calcluation for length of HEAVY BOARD gauge conduit pipe 15 mm Diameter, for earth wire. From main distribution board (MBD) to top of motor foundation (Total length of 15mm conduit required) x 2 = 10 x 2 = 20 mtrs.

Calculation for 3 core PVC cable of size 4mm2 From 3 φ energy meter to MBD = 1.5 + 3 + 1.5 = 6 meters. From MBD to 3 φ induction motor= 1.5+0.2+0.5+0.2+0.25 =2.6 meters. Total = 8.65 meters. 10% wastage = 0.865 meters. Total length = 9.51 say 10 meters.

Calculation for length of 8 SWG GI Earth wire From MDB to 3φ induction motor = (1.5+0.2+0.5+0.2+0.25)x2 = 2.65 x 2 = 5.30 meters. 10% wastage = 0.53 meters Total length = 5.83 or say 6 meters.

SINGLE LINE DIAGRAM

Specification of material LIST OF MATERIALS S. No. Specification of material Qty. Rate Amount 1. TPIC, main switch, 16 amps rating, 500V grade 1 No. 700 700.00 2. Heavy gauge conduit pipe, black enamel 15 mm diameter Conduit accessories : conduit bends Conduit saddles to hold conduit with wall 30mts 2 Nos. 4 Nos. 30/mts 20/each 40/doz. 900.00 40.00 4.00 3. Flexible conduit 15 mm diameter 1 m. 30/mts. 30.00 4. Flexible conduit coupler to connect rigid conduit and flexible conduit together 5. Flexible conduit attachment with locks nuts to attach flexible conduit with main switch, starter, motor etc 6 Nos. 5/each ` 6. PVC insulated, aluminum conductor, 3 core, 4mm2 or 1/ 2.24mm diameter, 660 volt grade wire 10mts 150/mt. 1500.00 7. 8 SWG, GI, earth wire 6 mts 50 300.00

Specification of material S. No. Specification of material Qty. Rate Amount 8. Earthing thimbles 16 amp rating with nuts and bolts to connect earth wire with components 10 Nos. 5/each 50.00 9. Iron clad board fabricated with angle iron and MS sheet of size 30cm x 45cm 1 Nos. 180/each 180.00 10. A> Rag bolt of dia 12mm and 20cm long with nut For holding iron clad board with wall B> Bolts with nut 10mm dia 30mm long, for fixing main switch and starter with MB 4 Nos. 8 Nos. 10/each 1/each 40.00 8.00 11. Teak wood guttis (plugs) for fixing conduit saddles with wall 30 Nos. 2/each 60.00 12. Wood screws, 25mm long for fixing saddles with wall 30.00 13. Caution plate (danger 440 volts) 1 No. 50 14. Shock treatment chart

Specification of material S. No. Specification of material Qty. Rate Amount 15. Civil engineering works such as grouting of Rag bolts for fixing main board and motor Control board, making motor foundation, Concrete pit, cover for pit etc. =1 ½ bag cement 500.00 16. Labour charges for civil engg. Works - 300.00 17. Transport of wiring material to work site. Contingencies @5% of total wiring cost. Total cost involved in power wiring. 100.00 4912.00 245.00 5157.00 18. Earthing set 2 Nos. complete as under assuming depth of earth electrode to be 7 meters using plate earthing system: G.I earth plate 60cmx60cmx6.36cm thick G.I pipe 15mm dia to enclose earth wire commencing from main board to earth plate for both sets 2 Nos. 24 mts 150/each 25/mt 600.00

Specification of material S. No. Specification of material Qty. Rate Amount 3. G.I pipe 20mm dia for watering i.e. from funnel to earth plate 4. 8 SWG GI earth wire from main board to earth plate 5. Cast iron frame 30cmx30cm for both sets 6.Cast iron frame 30cmx30cm for both sets 7. Funnel with wire mesh 8. G.I bolts 10mm dia, 25mm long with nuts 9. Earthing thimbles 60 amps rating to connect earth wire with earth plate 10. Charcoal 15 kg for each set 11. Salt 20 kg for each set 12. G.I pipe bends for 15mm dia pipe 13. Soldering material for soldering earth wire with thimble 14. Cement, sand, concrete 15. Labour for earthing 16. Expenditure on transportation of material Total cost involved on earthing Total cost for providing power wiring including earthing system=5157+2480 10 mts 6 mts 2 Nos. 4 Nos. 30 kg 40 kg 6 Nos. - 25/mt 50/mt 50/each 20/each 15/each 2/each 6/each 4/kg 2/kg 10/each 250.00 300.00 100.00 40.00 30.00 8.00 12.00 120.00 80.00 60.00 500.00 2840.00 7997.00