In my opinion, the real problem with 30 AMP RV receptacles, is that campgrounds are lacking 50 AMP receptacles (power) and many 30 AMP RV’s should have been equipped with 50 AMP service. Adding up the potential current draw on a 30 AMP RV with a roof air conditioner, electric water heater, electric refrigerator, microwave/convection oven, converter for powering 12V TV’s lights, fans, charging batteries, and anything else and it is a simple formula for disaster when there is only an electrical connection (receptacle) rated for only 24 AMPS of continuous power consumption. And then, those pesky 50 AMP RV’s that have no choice but to adapt down to a 30 AMP receptacle. Reminds me of Green Acres Season 1 Episode 9 (1965) “You Can't Plug in a 2 with a 6.”
I should do a deep dive into NEC 210.20(A). But be aware that it's not written in layman's terms, so it can be difficult to understand unless you're an electrician or electrical engineer who has studied the National Electrical Code. In fact, each AHJ (Authority Having Jurisdiction aka Electrical Inspector) has their own interpretation of the code.
NEC 210.20(A) Continuous and Noncontinuous Loads
Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent device shall not be less than the noncontinuous load plus 125 percent of the continuous load.
Exception: Where the assembly, including the overcurrent devices protecting the branch circuit(s), is listed for operation at 100 percent of its rating, the ampere rating of the overcurrent device shall be permitted to be not less than the sum of the continuous load plus the noncontinuous load.
There were several things about what happened here that are puzzling. First, he said he was there in the winter and there was minimal summer use but also said the ACs were on constantly. He said he found 11 bad receptacles which suggests a systemic problem like improper torque (as you suspected), a bad batch of receptacles (or poor quality as you suspected), or possibly moisture and corrosion although you’d think he’d mention that. Maybe with it being Arizona, the temperature in got so high in summer and so cold in winter that it contributed to the problem. The whole story is a bit mysterious. I wish there was more info.
Wow, that’s scary. I’m guessing they would be UL approved and the bar would be much higher than 300 insertions. That’s only about a year of use in a busy campground!
In my opinion, the real problem with 30 AMP RV receptacles, is that campgrounds are lacking 50 AMP receptacles (power) and many 30 AMP RV’s should have been equipped with 50 AMP service. Adding up the potential current draw on a 30 AMP RV with a roof air conditioner, electric water heater, electric refrigerator, microwave/convection oven, converter for powering 12V TV’s lights, fans, charging batteries, and anything else and it is a simple formula for disaster when there is only an electrical connection (receptacle) rated for only 24 AMPS of continuous power consumption. And then, those pesky 50 AMP RV’s that have no choice but to adapt down to a 30 AMP receptacle. Reminds me of Green Acres Season 1 Episode 9 (1965) “You Can't Plug in a 2 with a 6.”
I should do a deep dive into NEC 210.20(A). But be aware that it's not written in layman's terms, so it can be difficult to understand unless you're an electrician or electrical engineer who has studied the National Electrical Code. In fact, each AHJ (Authority Having Jurisdiction aka Electrical Inspector) has their own interpretation of the code.
NEC 210.20(A) Continuous and Noncontinuous Loads
Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent device shall not be less than the noncontinuous load plus 125 percent of the continuous load.
Exception: Where the assembly, including the overcurrent devices protecting the branch circuit(s), is listed for operation at 100 percent of its rating, the ampere rating of the overcurrent device shall be permitted to be not less than the sum of the continuous load plus the noncontinuous load.
There were several things about what happened here that are puzzling. First, he said he was there in the winter and there was minimal summer use but also said the ACs were on constantly. He said he found 11 bad receptacles which suggests a systemic problem like improper torque (as you suspected), a bad batch of receptacles (or poor quality as you suspected), or possibly moisture and corrosion although you’d think he’d mention that. Maybe with it being Arizona, the temperature in got so high in summer and so cold in winter that it contributed to the problem. The whole story is a bit mysterious. I wish there was more info.
Interestingly, I have an unpublished report showing that the TT-30R campground receptacle is only rated for 300 insertions.
Wow, that’s scary. I’m guessing they would be UL approved and the bar would be much higher than 300 insertions. That’s only about a year of use in a busy campground!