By Mike Sokol
Welcome to my J.A.M. (Just Ask Mike) Session, a weekly column where I answer your basic electrical questions. If you’re a newbie who’s never plugged in a shore power cord (or ask – what’s a shore power cord?), or wonder why your daughter’s hair dryer keeps tripping the circuit breaker, this column is for you. Send your questions to Mike Sokol at mike (at) noshockzone.org with the subject line – JAM.
Dear Mike (aka J.A.M.),
This just happened to the 30-amp plug on my surge protector. (picture). Any idea what would’ve caused it? I blame the outlet in the pedestal, but the park owner (of course) blamed the surge protector. What can cause a brand-new shore power plug to burn up? —RVillager Shanik117
See the picture below, which you can click on to enlarge.
This is most likely caused by loose or corroded contacts in the pedestal outlet itself, or possibly loose screws in the outlet. Remember last week I said you should turn OFF the circuit breakers before plugging or unplugging your shore power cord from the pedestal? Well, this is what happens when the pedestal outlet is worn out from too many previous campers who plugged and unplugged their power cord without turning off the breaker. The brass contacts inside of the outlet become pitted or corroded, which reduces the surface area and increases the resistance, which causes heating. The heating causes the spring-loaded contacts to soften and loosen up. Then the loose contacts create even more resistance, which causes even more heating to occur. And voila! Fricassee of shore power plug.
NOTE: If you notice that your shore power plug is loose when plugging into a campground pedestal, DO NOT accept the pedestal since it may destroy your shore power cord or surge protector. And just like the example above, the campground may not want to pay for your damages. So ask to be moved to another campsite/pedestal or proceed at your own risk.
OK, everyone. Remember that electricity is a useful and powerful force, so we all need to pay attention to safety precautions while using it.
Let’s play safe out there….
Mike Sokol is an electrical and professional sound expert with 40+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.