Quick Reference of Diesel Generator Set-(Part-1).

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 (Ne…