Quick Reference of Diesel Generator Set-(Part-1)
Standard Size of The DG sets | ||||
| KVA | KVA | KVA | KVA | KVA |
| 7.5 KVA | 20KVA | 35 KVA | 62.5 KVA | 100 KVA |
| 10 KVA | 25 KVA | 40 KVA | 75 KVA | 125 KVA |
| 15 KVA | 30 KVA | 50 KVA | 82.5 KVA | 200 KVA |
Bar Size for D.G Foundation | |
| Rating of D.G set | Size of Bar |
| Up to 82.5 KVA | 10MM |
| 100 KVA To 200 KVA | 12MM |
| 250 KVA to 500KVA | 16MM |
Minimum Capacity of Daily Fuel Service Tank (AS per CPWD) | |
| Capacity of DG set | Minimum Fuel Tank Capacity |
| Upto 25 KVA | 100 Litres |
| Above 25 to 62.5 KVA | 120 Litres |
| Above 62.5 KVA to 125 KVA | 225 Litres |
| Above 125 KVA to 200 KVA | 285 Litres |
| Above 200 KVA to 380 KVA | 500 Litres |
| Above 380 KVA to 500 KVA | 700 Litres |
| Above 500 KVA to 750 KVA | 900 Litres |
Battery Size for D.G Set (AS per CPWD) | |||
| DG Set Capacity | Battery Capacity (AH) | Cu Cable Size (Sq. mm) | Electrical System (Volts) |
| Upto 25 KVA | 88 | 35 | 12 |
| Above 25 KVA upto 62.5 KVA | 120 | 50 | 12 |
| Above 62.5 KVA upto 82.5 KVA | 150 | 50 | 12 |
| Above 82.5.KVA upto 125 KVA | 180 | 50 | 12 |
| Above 125 KVA upto 500 KVA | 180 | 70 | 12 |
| Above 500 KVA | 360 | 70 | 24 |
| Depths of PCC (Plain Cement Concrete) for DG Set (As per CPWD) | |
| DG Set Capacity (KVA) | Typical Depth of PCC Foundation (For soil bearing capacity 5000 kg/sqm) |
| 750-2000 | 600 mm |
| 625 | 400 mm |
| 320-500 | 400 mm |
| 200-320 | 400 mm |
| 82.5 -200 | 400 mm |
| Upto 82.5 | 200 mm |
Area Required For Generator in Electrical Sub Station (As per NBC) | ||
| Capacity kVA | Area m2 | Clear Height below the Soffit of the Beam m |
| 25 | 56 | 3.6 |
| 48 | 56 | 3.6 |
| 100 | 65 | 3.6 |
| 150 | 72 | 3.6 |
| 248 | 100 | 4.2 |
| 350 | 100 | 4.2 |
| 480 | 100 | 4.2 |
| 600 | 110 | 4.6 |
| 800 | 120 | 4.6 |
| 1010 | 120 | 6.5 |
| 1250 | 120 | 6.5 |
| 1600 | 150 | 6.5 |
| 2000 | 150 | 6.5 |
Starting Current for D.G set | |
| Type of Load | Starting Current |
| Motors over 50 HP | 6 X motor rated current |
| Variable frequency drive motors | 2 X motor rated current |
| Uninterruptible power supply (UPS) loads | 1.5 X UPS rated current |
| Battery charger loads | 2.5 X Charger rated current |
| Non-Linear Load | 1.5 to 2.5 X rated current |
| Medical imaging loads | 1.1 X Rated current |
| Soft Starter Motor | 1.2 X motor rated current |
| DOL Starter | 4 X motor rated current |
| Star-Delta Starter | 3 X motor rated current |
| Auto Transformer Starter | 1.5 X motor rated current |
| Most generators are capable of delivering 300% of the rated current for 10 seconds | |
Stand by D.G Permission As per PSEB | ||
| D.G Set Capacity | Permission | Remarks |
| Up to 10 KW(11 KVA) | No permission is required. Also prior sanction of CEI is not required. | |
| 10 KW (11 KVA) to 250 KVA | ||
| 250 KVA to 1 MVA | ||
| 1 MVA to 2.5 MVA | Permission is required. Also prior sanction of CEI is required | The capacity of D.G Set should not exceed 1.2 times of the sanctioned Load. |
| 2.5 MVA to 5 MVA | ||
| Exceeding 5 MVA | ||
Sound Level of Diesel Generator (ANSI 89.2&NEMA 51.20): | |
| KVA | Max. Sound Level |
| <9 KVA | 40 DB |
| 10 KVA to 50 KVA | 45 DB |
| 51 KVA to 150 KVA | 50 DB |
| 151 KVA to 300 KVA | 55 DB |
| 301 KVA to 500 KVA | 60 DB |
Exhaust Stack Height | |
| Up to 1000KVA D.G | Total Height of stack (Meter) = (Height of Building Where D.G Installed +0.2 ) X √D.G Capacity in KVA |
| More than 1000KVA D.G | 30 Meter height or more than 3 meter height of building which is higher. |
Height of stack (Meter) | |
| Generator Sets | Total Height of Stack in Meters. |
| 000 to 050 KVA | Height of Building + 1.5 Meter |
| 050 to 100 KVA | Height of Building + 2.0 Meter. |
| 100 to 150 KVA | Height of Building + 2.5 Meter |
| 150 to 200 KVA | Height of Building + 3.0 Meter |
| 200 to 250 KVA | Height of Building + 3.5 Meter |
| 250 to 300 KVA | Height of Building + 4.0 Meter. |
D.G Room Air Requirement | |
| D.G Set | Air Requirement |
| 275 KVA | 605 Cu. Meter / Min |
| 320 KVA | 625 Cu. Meter / Min |
| 400 KVA | 854 Cu. Meter / Min |
| 500 KVA | 1065 Cu. Meter / Min |
| 600 KVA | 1286 Cu. Meter / Min |
Noise Limit of D.G Set As per CPWD, India |
| Up to 1000 KVA (manufactured after 2005) =75 dB(A) at 1 meter from the enclosure surface |
| The acoustic enclosure or acoustic treatment of the room shall be designed for minimum 25 dB(A) insertion loss or for meeting the ambient noise standards, whichever is on the higher side. |
| The measurement for insertion loss may be done at different points at 0.5 m from the acoustic enclosure / room, and then averaged. |
| The DG set shall be provided with proper exhaust muffler with insertion loss of minimum 25 dB(A). |
Foundation & Earthing for D.G Set (As Per CPWD) | |
| Iteam | Descriptions |
| D.G set inside Room | A PCC foundation (1:2:4, M-20 grade) of approximate depth 150 mm above the finished Genset Room Floor level |
| The length and breadth of foundation should be at least 250 mm more on all sides than the size of the enclosure. | |
| D.G set in Open Room | A PCC (1:2:4, M-20 grade) foundation of weight 2.5 times the operating weight of the Genset with enclosure or as recommended by the Genset manufacturer, whichever is higher |
| 300 mm of this foundation height should be above the ground level. The length and breadth of foundation should be at least 250 mm more on all sides than the size of enclosure. | |
| Earthing | Copper plate earthing (Neutral Grounding) shall be provided for DG Sets of capacity 500 KVA or above |
| whereas G.I. plate earthing (Neutral Grounding) shall be provided for DG Sets below 500 KVA capacity. The body earthing shall generally be of G.I | |
| Numbers of earthing for each DG Sets | 2No’s earthing sets for Genset/ control panel body. |
| 2No’s earthing sets for neutral. | |
| In case there are more than one DG Set in one location, independent two nos. neutral earthing shall be provided for each DG set. However, two nos. earthing sets shall be common for the body earthing of DG Sets | |
| DG Set of 500 KVA capacity or above:- Copper strip | |
| DG Set below 500 KVA capacity:- GI strip | |
D.G Spacing Guidance | |||
| Description | DG set with Acoustic Enclosure | Open DG set in room. | |
| in Open Area | in Closed Area | ||
| Free space on both sides | Min. 1.5 m | Min. 1.5 m | Min. 2 m |
| Free space at front side (Radiator Hot air outlet at Front) | Min. 3 m | Min. 3 m | N/A |
| Free space at front side (Radiator Hot air outlet at Top) | Min. 1.0 m | Min. 1.5 m | N/A |
| Free space at rear side (Alternator) | Min. 2 m | Min. 2 m | Min. 2 m |
| Fresh air inlet opening area | N/A | N/A | Min 1.5 times of the Radiator area. |
| Hot air discharge opening area | N/A | N/A | Min 2.5 times of the Radiator area. |
| Distance between two sets | Min 1.5m between two canopies | Min 1.5m between two canopies | Min 1.5m between two foundations. |
D.G Detail according to Size | |||||
| D.G Size (KVA) | L x W x H (Canopy) mm | Approx Weight (Kg) | Fuel Tank (Ltrs) | Fuel Consumption (Ltr/hr) | Oil Consumption (Ltr/hr) |
| 12.5 | 2040 x 1230 x 1450 | 1050 | 60 | 2.3 | 0.02 |
| 15 | 2040 x 1230 x 1450 | 1050 | 65 | 2.3 | 0.02 |
| 20 | 2240 x 1230 x 1450 | 1300 | 65 | 3.7 | 0.03 |
| 30 | 2510 x 1130 x 1450 | 1300 | 65 | 6.3 | 0.03 |
| 40 | 3350 x 1180 x 1650 | 1500 | 100 | 7.8 | 0.03 |
| 50 | 3350 x 1180 x 1650 | 1500 | 100 | 8.3 | 0.03 |
| 62.5 | 3350 x 1180 x 1650 | 1930 | 150 | 10.5 | 0.03 |
| 75 | 3605 x 1405 x 1600 | 1950 | 150 | 13 | 0.03 |
| 100 | 3940 x 1700 x 1850 | 2500 | 300 | 15.7 | 0.05 |
| 125 | 3950 x 1700 x 1850 | 2700 | 300 | 19 | 0.05 |
| 140 | 4600 x 1850 x 1950 | 3580 | 300 | 22.6 | 0.06 |
| 160 | 4600 x 1850 x 1950 | 3720 | 450 | 25.9 | 0.14 |
| 180 | 4970 x 1730 x 2045 | 3870 | 450 | 27.7 | 0.14 |
| 200 | 4970 x 1730 x 2045 | 3950 | 450 | 29.8 | 0.14 |
| 250 | 4970 x 1730 x 2050 | 4660 | 450 | 37.7 | 0.15 |
| 275 | 5700 x 2030 x 2515 | 5860 | 450 | 50 | 0.15 |
| 320 | 5700 x 2030 x 2515 | 5860 | 450 | 57 | 0.3 |
| 400 | 5905 x 2030 x 2520 | 6180 | 990 | 65.1 | 0.3 |
| 500 | 6205 x 2030 x 2550 | 6990 | 990 | 81.3 | 0.3 |