Twin, or ‘two-for-one’, breakers allow the connection of two, separately-protected circuits in the space of one standard breaker. Two circuit overcurrent protective devices (COPDs) connect to a single leg of the phase bus bar in the breaker panel, effectively doubling the capacity of the breaker panel in terms of number of branch circuits connected. The total power capacity of the panel does not change with the addition of twin type breakers (and is largely unaffected by what breakers may be installed — a common misconception that can lead to the wrong conclusion that a panel is overloaded simply because the Ampere rating of all breakers adds to more than the main breaker Ampere rating).
How do I tell whether my breaker panel accepts twin breakers?
Most breaker panels are rated to accept at least a few twin breakers. Some accept twins throughout the panel, and some accept no twins at all. The diagram inside the panel cover should indicate which breaker positions accommodate twin breakers (see photos).
This project on S Melville St. features:
200A Service Upgrade and new receptacles
- 200A service upgrade and new receptacles from existing 100A, with 30+ breaker positions and GFCI receptacle at panel location in garage.
- Add 4 receptacle outlets, including a GFCI for the 2nd floor bathroom.
- Convert (3) 220V receptacles to (3) 120V receptacles on dedicated AFCI breakers.
This was a straightforward 200A service upgrade job on the service side, but a nest of badly labeled branch circuit conductors in a shared raceway (3/4″ conduit) made re-connection at the new service disconnect/breaker panel more difficult than it could have been.
I include a GFCI receptacle with service equipment replacements/upgrades, and in this case I also installed a switched utility service light to facilitate finding breakers or further work at the service disconnect/distribution breaker panel location.
Frayed service cable / power quality
What type of electric service cable damage are you looking out for?
If you can see exposed aluminum strands on your service entrance cable, it has frayed to the point where you should replace it. Cost may vary from $750 – $2200, depending on your service capacity (usually between 100A – 200A for residential electric accounts) and the capacity of your replacement service (for those wanting central air conditioning, an upgrade from 100A to 150A or 200A will often be needed; subsequent solar PV or micro wind power installations over 5kW capacity may be cheaper to install if the existing service is larger than 100A).
Customer Resource Blog Categories
Off-site Links ->
- Annapolis Home Inspection, LLC Aluminum branch circuits, homes 1965-1972
- ComplianceAndSafety.com OSHA Electrical Safety Training
- Electric Monk TV (YouTube) Video channel for PhillyLicensedElectrician.com Robert Monk
- EnergyConservation HowTo A tinkerer genius discusses energy conservation and his ladder system for accessing the attic (where a lot of energy-saving work happens).
- PennFuture Energy Center Energy and energy efficiency news for the Commonwealth of Pennsylvania
- Phila area rife with building efficiency upgrade opportunities Philadelphia Inquirer article discusses recent study showing Philadelphia’s inner-ring suburbs stand to save from energy conservation retrofits.
- Philadelphia Row-house Manual A design, maintenance, and modifications manual for our most widely-used form of housing.
- Robert Monk Robert Monk’s personal blog
- SolarCities (DOE) Solar PV Levelized Cost Interactive Comparator Simple graph compares ‘levelized cost’ of energy from solar PV to conventional grid rates, with a time-slider interactive feature.
- The Circuit Detective – Solve Home Electrical Problems Yourself! Electrical troubleshooting procedures pitched to homeowners.
- The Energy Co-op Blog from a leading alternative energy provider in PECO territory, includes fun conservation tips.
- Weatherization: the anti-Solyndra Salon.com article praising the continued success of the federal Weatherization Assistance Program (WAP), low-income energy-savings and job-creation.
- West Philly Tool Library Official site of WPTL, Philly’s own community tool lending library: like a book library, but tools!
- WestPhillyLocal .com Site name say sit all.
- Bartram's Gardens Founded in Philadelphia’s colonial era, today the gardens continue pioneering in horticulture and agriculture with a variety of herbs, trees and other vegetation in an arboretum/gardens on the Schulkill River banks, and a new farm abutting sadly neglected
- HiddenCity Philadelphia Surprising places it takes an adventurer to discover; events, too.
- Philly Household Hazardous Waste Drop-off Schedule City of Philadelphia dates and places for disposing of spent batteries, CFL lamps, unused paint and cleaning products, etc. LovePhilly: don’t pour these in the drain or send them out with the trash.
- Reading Terminal Market Purveyors of fine foods and foodie stuff, all under one roof downtown under the PA Convention Center
- Secret Garden on the Rails Jacques-Jean Tiziou shows some dramatic natural and urban and naturalized-urban scenes along abandoned rails of Philadelphia
- Sketch Burger, Fishtown A vegan-friendly burger joint with a #1 in Philly contender beef burger, best fries that somehow stay fresh for 1/2 hour while you tackle burger, and a vegan cafe vibe of friendly folks.
- WXPN: Philly sings in key of love Love songs by Philly artists