Siemens Standby Generators, Manual

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Generator Sizing Guide
Onsite Estimating Sheet
Contractor _____________________________________________
Email _________________________________________________
Phone _________________________ Fax ___________________
Job Name _____________________________________________
Date___________ Location _______________________________
VOLTAGE 120/240 1Ø 120/208 3Ø 277/480 3Ø
TYPE Natural Gas LP Vapor LPV)
ELEC. SERVICE 100 Amp 200 Amp 400 Amp
600 Amp Other________
Before installation contact local jurisdiction to confirm all
requirements are met. Jurisdictions may vary. Siemens
recommends contacting local authorities prior to installation.
Loads: Look for heavy building loads such as refrigeration,
air conditioning, pumps or UPS systems.
Use the following for sizing and determining generator kW.
QT Upgrade Required
These applications require an upgrade from the QT Series:
NEC 695 Fire Pumps
NEC 700 Emergency Systems
NFPA 20 Fire Pumps
NFPA 99 Healthcare
NFPA 110 Emergency Systems
Reference Codes
Related Codes and Standards:
NEC 225 Branch Circuits and Feeders
NEC 240 Overcurrent Protection
NEC 250 Grounding
NEC 445 Generators
NEC 701 Legally Required Standby
NEC 702 Optional Standby
NFPA 37 Installation and Use of Stationary Engines
NFPA 54 National Fuel Gas Code
NFPA 58 LP Gas Code
Motor Load Table (refer to Table 1)
Device
HP RA LRA kW Running Starting
(= HP) kW
Table 6
Non-Motor Load Table (refer to Table 2)
Device
Amps kW
Table 7
Starting kW for HP < 7.5 starting kW = HP x 3
Starting kW for HP > 7.5 starting kW = HP x 2
Starting kW for loading with no listed HP, calculate HP based on running amps
in the chart on the right.
Recommended Generator Size ________ Refer to Generator Sizing Instructions on other side of this sheet.
INSTALL NOTES:
1. Suggested concrete pad minimum thickness of 4" with 12" overhang on all sides. Fiberglass pad included with air-cooled products.
2. Consult manual for installation recommendations.
3. Consult local authority having jurisdiction for local requirements.
To Calculate kW (refer to page 2 for shortcut)
120 V 1Ø Amps x 120/1000 = kW
240 V 1Ø Amps x 240/1000 = kW
208 V 3Ø Amps x 208 x √3 x PF/1000 = kW
240 V 3Ø Amps x 240 x √3 x PF/1000 = kW
480 V 3Ø Amps x 480 x √3 x PF/1000 = kW
PF is application power factor (worst case 1.0)
Typical application power factor is 0.95.
Resources in Sizing Guide
Surge Capability Chart – References running amps of units and LRA
Propane Tank Sizing Chart – Measures fuel consumption of generator units
Motor Load Reference Guide – Reference guide for basic motor loads
Non-Motor Load Reference Guide – Reference guide for non-motor loads
Fuel Piping Sizing Chart – Assists in calculating adequate pipe size for
natural gas and propane
UPS – Generator Compatibility
UPS Information
1.5 x kVA rating for a filtered system
3 – 5 x kVA rating for an unfiltered system
Siemens recommends you refer to the Siemens UPS Generator
Compatibility sheet and notify the manufacturer of the UPS
system to assist in your installation.
Transfer Switch Availability
SR6ST
– 100 and 200 Amp service entrance rated
RTS
– 100, 200, 400 Amp
SR6SI switch only works with R100 controller.
XT 6XR
– 100, 150, 200, 300, 400, 600, 800 Amp
HTS switch only works with H100 controller. Avail. in
NEMA 1, NEMA 3R and NEMA 12. Refer to Seimens
product catalog for the appropriate transfer switch.
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