WHOLE HOUSE
ELECTRICAL GENERATOR
Lewis Thompson – W5IFQ
3 July 2012
Previous Emergency Power
Sources
200 AH, 12 VDC Storage
Batteries
2 KW AC Generator
First “Whole-House” Generator
20 Hours of fuel
Manual Residential Transfer Switch
10 KW Tri-fuel Generator
10KW Tri-Fuel Generator
Engine – Briggs & Stratton (Daihatsu) Vanguard V-Twin 16 HP OHV w/12 Alternator
Electric starter
Generator – Hercules, brushless, 100% power factor rated
Residential Transfer Switch – Manual, 60 A, with Hubble Connector
Power Cable – 50 ft. 6-3 with 220 VAC matching connectors
Original House Wiring
Outside Breaker Box
AC
30A
AC
30A
220V
Mains
Inside Breaker Box
20 – 120V Breakers
Wall plugs
Appliances
Lights
Gas Furnace Blowers
125A
Oven
30A
(Neutral not shown)
Drier
30A
House
60A
Total Power – 60A at 220V
Or 13.2 KW
Original House Wiring
Outside Breaker Box
AC
(Neutral not shown)
30A
AC
30A
220V
Mains
Inside Breaker Box
20 – 120V Breakers
Wall plugs
Appliances
Lights
Gas Furnace Blowers
125A
Oven
30A
Note:
No AC
No Electric Oven
But have central heat
Drier
Generator
Input
30A
Xfer Switch
House
60A
Total Power – 60A at 220V
Or 13.2 KW
Manual Residential Transfer Switch
(60 A – Break before Make)
Fuel Consumption
(10 KW Load)
• Gasoline – 1.25 gal/hr
– Limited storage life (1 year with Sta-Bil)
• Propane – 2.2 gal/hr
– Can obtain permit from AFD
– Best option if no natural gas service
– Tank can be buried (250 gal standard)
• Natural Gas – 150 cu ft/hr
– Probably will need 2nd service line
Natural Gas Service Problem
Gas Piping in house
Insufficient to power
10 KW generator.
New pipe from meter
Needs about 250 ft
Of 1” line. This pipe
needs to run either
under patio or
driveway.
Decision to just run
on gasoline until
Propane tank installed
Gas Service
Electrical
Utility input
20 KW Whole-House Generator
• Decision Process
– Most probable time to lose utility power would be
summer (hurricane, tornado, utility failure, rolling
blackouts).
– House very uncomfortable without air conditioning
(not designed for cross ventilation)
– Installed new AC units with 40% reduction in current
(EER = 20). Whole house consumption measured at
less than 20KW. (13.4 KW)
– Increased confidence in natural gas source (Texas
Gas Company).
Natural Gas Solution
(Austin Generator Service)
Texas Gas Company
wants to sell you gas!
Only cost to me was
ditching from sidewalk
to meter ($778).
street, curb, sidewalk
excavation and repaving
was paid by Gas Co.
Existing Gas
Service
New
Gas
Service
I pay about $13/mo more
for meter minimum plus
gas used during weekly
generator exercising.
Electrical
Utility input
20 KW Whole-House Generator
Installation Events
• Selected Generator and Automatic Transfer Switch
• Proposal from Austin Generator Co. – 9/9/2011, total
$9026.60 including electrical installation, natural gas
plumbing, startup and testing. New gas line and meter
not included.
• Removed manual transfer switch, reconditioned 10 KW
generator and sold all components.
• Ordered new “yard line” – 55 ft of ¾” plastic gas pipe $788.70 from Texas Gas Service.
• Completion – 12/27/2011
• Total Cost - $9815.30
Motor-Generator
• Generac – Guardian model 5875
– Engine
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2 cylinder, OHV, 999 cc, 36 HP
Air cooled, 3600 rpm
Sound Output – 66 dB(A) at 23 ft.
Fuel Consumption (full load)
– NG – 294 cu. ft./hr.
– LP – 2.9 gal/hr.
• Aluminum Enclosure
• Maintenance Interval – 200 hr.
– Generator
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240 VAC at 83.3 A (LP), 75 A (NG)
20 KW (LP), 18KW (NG),
Harmonic distortion - <5%
Regulation - +/- 1%
Transfer Switch & Controller
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Transfer switch – 200 A
Automatic transfer with utility interrupt delay (10-30 sec)
Utility setpoints, 60% dropout, 80% pickup (240 VAC)
Generator auto start with 5 second delay before load
transfer.
Monitor of generator output voltage and frequency.
Programmable load sequencing (if needed).
Engine cool down of 1 minute before shutdown.
Weekly exercise for 12 minutes (programmable)
Smart battery charger
NMEA enclosure
NG Line Installation
Generator Placement
Transfer Switch Wiring
Outside Breaker Box
AC
30A
XFER Switch
AC
Utility Meter
30A
220V
Mains
125A
Oven
30A
Ctrl
Drier
30A
(Neutral not shown)
House
Generator
60A
Transfer Box Installation
Transfer Switch to Generator
City Inspection Required
NG Plumbing
City Inspection Required
System Startup & Testing
Installation Completion
QUESTIONS?
Lewis Thompson
W5IFQ, AAA6TX
[email protected]
[email protected]
[email protected]
[email protected]
Cell (512) 587-9944
Home (512) 892-8815