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.
The following just showed up on my RV Electricity Facebook Group this week, and it’s a good reminder to never ignore any burned electrical smells. Read and heed below.
I found this… I was noticing some heat and smell from the panel when running the A/C for long periods. This is a 30-amp setup and it’s been fine. I found the neutral terminal screw for the main feed was pretty loose. Would that cause the heat buildup or should I be looking at something else? I’m pretty certain it was just from a loose contact. Cut and re-stripped the wire and will run things again to see if it gets warm. I’m just happy that I noticed. Any thoughts would be appreciated! Thanks. —Scott
Your quick action saved your power panel from additional damage, and possibly prevented a fire in your RV if it had been left unchecked. So, great job on realizing that hot electrical smells in your RV usually mean trouble. It’s always best to check.
We cover this sort of thing in a lot more depth on my RVelectricity Facebook Group and my RV Electricity Newsletter, but the basics are that any loose electrical connection will tend to heat up and can cause damage to the wiring. That’s why I suggest that all electrical screws in your power panel should be checked for tightness at least once a season. While it’s true that you don’t have to do this sort of thing in your sticks-and-bricks house, it’s not bouncing down the highway possibly thousands of miles a year and going through temperature swings from below 0 to above 100 degrees like the electrical system in your RV. All that vibration and the hot/cold temperature swings tend to loosen up your electrical connectors.
However, as I’ve written before, you just don’t want to get cranking and possibly over-torque the terminating screws – which can cause more problems if you strip them, and possibly break off a relay terminal in your Automatic Transfer Switch (ATS). That’s expensive and can leave you without power until you get a replacement unit, so don’t go there.
And make sure you have and use the correct type of bit (usually square) in the screwdriver (not just a flat blade) since you don’t want to damage the terminating screws by slipping off of them. Some of the damage I see by casual “non-electricians” is pretty sad and unnecessary if only they had used the right tools in the first place.
I also highly recommend you use a torque limiting screwdriver set to the correct torque, which is usually around 35 in/lbs (not ft/lbs), and often marked right inside the cover of your ATS. I have an industrial duty torque screwdriver for my own work, but that’s probably overkill for the average user. So, as I’ve noted here before, you can get a nice one made for gunsmiths for less than $50 which should do the trick. You can get one HERE.
Also, if any of the wires were damaged from overheating like the one in the picture, you need to cut them back to get to the unburned insulation and fresh copper. If it’s then too short to make the connection, I recommend you use WAGO lever splice connectors inside of the box to add on a length of the proper gauge and color wire. WAGO lever splice connectors are available on Amazon.com and other electrical parts houses, and are really handy for this sort of splice.
Finally, make sure ALL power is off before you even open up a panel as those are deadly voltages inside, and you’ll be reaching in with a metal screwdriver. So, disconnect from shore power, generator power and inverter power. Any of the above can kill you.
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 50+ 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.
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##RVDT 1247;##RVT 930