How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manufactured and modular homes
Why is there no main shut-off breaker in my electric panel?
Thursday, September 5, 2019
Almost all of the thousands of house electrical systems we have inspected over the years comply with the requirement for a main electrical disconnect. It may not appear that your panel is compliant, even though it actually is, because of a couple of things:
1) A main breaker is only required at the service panel, which is the first electrical panel after the meter. Any subpanels are only required to have a disconnect breaker upstream in the main panel. Some houses have a service panel, which may sometimes contain only the single disconnect breaker, on the exterior wall next to the meter and a distribution subpanel inside the home. Condominiums often have the service disconnects integral with the meters in clusters at an exterior wall, as shown below. The meter cluster might also be in a meter room somewhere in the building. So the inside panel is technically a subpanel and does not have a main breaker.
2) The National Electrical Code (NEC) allows it to take shutting off up to six breakers in the main service panel to turn off all power. This main breaker exception has been in the code since 1933 and there was a period in the mid-twentieth century when a type of panel called a “split bus” that utilized that allowance was popular. But each disconnect breaker had to be clearly marked as a “main disconnect,” usually by affixing a sticker next to it, like in the photo below. To learn more, see our blog post What is a split bus electric panel? Split bus panels are no longer manufactured and now a just footnote in electrical history, but the allowance for up to six switch-throws to shut off all power is still sometimes used in smaller service panels, like at mobile home and RV parks.
• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •
Here’s links to a collection of our other blog posts about ELECTRIC PANELS:
• What causes copper wires to turn green or black in an electric panel?
• What is the maximum number of circuit breakers allowed in an electric panel?
• When should a corroded or damaged electric panel cabinet or disconnect box be replaced?
• What is a tandem circuit breaker?
• When did arc fault circuit interrupter (AFCI) breakers first become required?
• Can an electric panel be located in a closet?
• Can an electric panel be located in a bathroom?
• Can you add circuit breakers by different manufacturers to an electric panel if they fit?
• My circuit breaker won't reset. What's wrong?
• How do I identify a combination AFCI (CAFCI) circuit breaker?
• What does a circuit breaker with a yellow or white test button indicate?
• What are the requirements for NM-cables entering an electric panel box?
• Why is a fuse box/panel an insurance problem for homebuyers?
• Why is bundled wiring in an electric panel a defect?
• What is the difference between GFCI and AFCI circuit breakers?
• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?
• What happens when you press the "TEST" button on a circuit breaker in an electric panel?
• What is a Dual Function Circuit Interrupter (DFCI)?
• What is the difference between "grounded" and "grounding" electrical conductors?
• What does it mean when a wire is "overstripped" at a circuit breaker?
• Why is an old fuse panel dangerous?
• Who is the manufacturer of those "bad" electric panels?
• Why is the circuit breaker stuck in the middle?
• What is a double tap at a circuit breaker?
• What is the right electric wire size for a circuit breaker in an electric panel?
• What is the life expectancy of a circuit breaker?
• My circuit breaker won't reset. What's wrong?
• Why do some breakers in my electric panel have a "TEST" button on them?
• What is the right size electric panel for a house?
• What do I need to know about buying a whole house surge protector?
• What is the maximum allowed height of a circuit breaker (OCPD) above the floor?
• What is the maximum height you can mount an electric panel above the floor?
• What is the code required clearance in front of an electric panel?
• What is the main bonding jumper and where do it find it in an electric panel?
Visit our ELECTRIC PANELS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.
Click Below
for Links
to Collections
of Blog Posts
by Subject
Top 5 results given instantly.
Click on magnifying glass
for all search results.
Search
This
Site
Buying a home in North/Central Florida? Check our price for a team inspection by two FL-licensed contractors and inspectors. Over 8,500 inspections completed in 20+ years. In a hurry? We will get it done for you.