Sizing Guide standby GENERATORS
Generator Sizing Guide General Information Important Notice This booklet is designed to familiarize estimators and installers with proper sizing guidelines for residential and commercial generators. The information is not comprehensive, nor does it replace or supercede any material contained in any of the written documents shipped with the equipment. This booklet should only be used in conjunction with the Owner’s Manual, Installation Manual and other technical documents shipped with each product.
Generator Sizing Guide Table 1 – Motor Load Reference AC and Heat Pumps Running Load Description 1 Ton (12,000 BTU) 2 Ton (24,000 BTU) 3 Ton (36,000 BTU) 4 Ton (48,000 BTU) 5 Ton (60,000 BTU) 7.5 Ton (85,000 BTU) 10 Ton (120,000 BTU) 10 Ton (120,000 BTU) 15 Ton (180,000 BTU) 15 Ton (180,000 BTU) 20 Ton (240,000 BTU) 20 Ton (240,000 BTU) 25 Ton (300,000 BTU) 30 Ton (360,000 BTU) 30 Ton (360,000 BTU) 40 Ton (480,000 BTU) 40 Ton (480,000 BTU) 50 Ton (480,000 BTU) 50 Ton (480,000 BTU) Hp 1 2 3 4 5 7.
Generator Sizing Guide Table 2 – Non-Motor Load Reference General Residential Running Load Description Electric heat per 1000 ft.2 Heat pump elements per 1000 ft.2 Dryer Hot tub Range oven Hot water Stove top per burner General receptacles per 1000 ft.2 Lighting per 1000 ft.2 Blow dryer Dishwasher Microwave Toasters kW 12 7 5.5 5 5 4.5 1.5 1 0.75 1.25 1.5 1 1 Amps at 120V 1ø n/a n/a n/a n/a n/a n/a n/a 8.3 6.3 10.4 12.5 8.3 8.
Generator Sizing Guide Table 3 – Surge Capability Siemens Liquid Cooled Generators Operating at <3600 RPM Size (kW) 25 70 80 100 130 Rated Output (Running Amps) 240V 1ø 208V 3ø 104 87 292 243 333 278 417 347 542 451 480V 3ø 38 105 120 150 195 Surge Capability LR Amps at 15% Voltage Dip 240V 1ø 208V 3ø 480V 3ø 71 47 26 275 183 106 275 183 106 371 247 142 546 364 209 Surge Capability LR Amps at 30% Voltage Dip 240V 1ø 208V 3ø 480V 3ø 133 89 52 550 366 212 550 366 212 738 491 284 1088 724 419 Surge Capa
Generator Sizing Guide Table 4 – Fuel Pipe Sizing Natural Gas kW 7 10 13 16 20 25 35 45 60 70 80 100 130 150 Pipe Size (in.) 0.75" 55 20 10 1" 200 85 50 40 20 10 1.25" 820 370 245 190 115 75 35 15 1.5" 800 545 425 265 180 95 60 25 5 2" 2.5" 3" 915 650 390 225 195 140 50 30 1185 710 630 460 215 150 2" 2.5" 3" 1030 725 445 260 230 165 70 45 1095 660 590 430 205 150 1305 660 490 950 660 370 260 145 75 65 40 LP vapor (LPV) kW 7 10 13 16 20 25 35 45 60 70 80 100 130 150 Pipe Size (in.) 0.
Generator Sizing Guide Table 5 – LP Vapor (LPV) Tank Sizing Vapor Withdrawal Tank Capacity Total (Gal.) Tank Capacity Useable (Gal.) Length (Inches) Diameter (Inches) Overall Ht. (Inches) Minimum Temp (°F) Tank Capacity (btu/hr.
Generator Sizing Guide UPS Generator Compatibility Passive (also referenced as standby or off-line) and Line-Interactive These technologies are most common for personal workstations and point of sale applications. They are typically single phase equipment with size ranges of 350 VA – 2000 VA for passive and 500 VA to 5000 VA for line-interactive. Passive UPS’s are the simplest type. Under normal conditions AC power passes straight through to the UPS load.
Generator Sizing Guide Onsite Estimating Sheet Contractor _____________________________________________ Email _________________________________________________ Phone _________________________ Fax ___________________ Job Name _____________________________________________ Date___________ Location _______________________________ 120/240 1Ø VOLTAGE Natural Gas TYPE ELEC.
Generator Sizing Guide Onsite Estimating Sheet Generator Sizing Instructions: There is not a single correct sizing solution. The instructions below identify multiple methods that, when mixed with good judgment, should result in a moderately sized generator. Remember to consider load growth, seasonality, and effects of starting motors. When motors start, they create a current surge that step loads the generator. As a result of this step loading, the generator will experience a voltage dip.
Generator Sizing Guide Onsite Estimating Sheet Contractor _____________________________________________ Email _________________________________________________ Phone _________________________ Fax ___________________ Job Name _____________________________________________ Date___________ Location _______________________________ 120/240 1Ø VOLTAGE Natural Gas TYPE ELEC.
Generator Sizing Guide Onsite Estimating Sheet Generator Sizing Instructions: There is not a single correct sizing solution. The instructions below identify multiple methods that, when mixed with good judgment, should result in a moderately sized generator. Remember to consider load growth, seasonality, and effects of starting motors. When motors start, they create a current surge that step loads the generator. As a result of this step loading, the generator will experience a voltage dip.
Generator Sizing Guide Onsite Estimating Sheet Contractor _____________________________________________ Email _________________________________________________ Phone _________________________ Fax ___________________ Job Name _____________________________________________ Date___________ Location _______________________________ 120/240 1Ø VOLTAGE Natural Gas TYPE ELEC.
Generator Sizing Guide Onsite Estimating Sheet Generator Sizing Instructions: There is not a single correct sizing solution. The instructions below identify multiple methods that, when mixed with good judgment, should result in a moderately sized generator. Remember to consider load growth, seasonality, and effects of starting motors. When motors start, they create a current surge that step loads the generator. As a result of this step loading, the generator will experience a voltage dip.
Notes
Siemens Energy & Automation, Inc. 3333 Old Milton Parkway Alpharetta, GA 30005 1-800-964-4114 infosea@siemens.com www.sea.siemens.com/generators ©2006 Siemens Energy & Automation, Inc. All Rights Reserved Siemens is a registered trademark of Siemens AG. Product names mentioned may be trademarks or registered trademarks of their respective companies. Specifications are subject to change without notice.
