about perfect for a 30 amp RV!

Dutch_12078 wrote:

time2roll wrote:

Dutch_12078 wrote:
If a park is seeing a significant voltage drop when full then the park infrastructure is substandard.

Still the system probably meets code as it was never anticipated how RVs would become such power hogs even having power management systems to keep that 30 amp outlet at the very max for extended periods if not 24/7.

The park may have met code when it was built, but current code sets the minimum required percentage of 50 amp versus 30 amp sites, along with other changes over the years designed to support newer RV's with high power requirements. A standard 30 amp breaker only supports a sustained 80% load (24 amps). A well designed park electrical system should also support a sustained 80% load. The problem isn't RV's with higher power requirements, it's parks that haven't kept up with the RV market changes.

There is nothing that can force a CG owner to update their electrical systems to the latest code edition. It just doesn't work that way. No CG is going to simply voluntarily spend many thousands of $$ and rip up their CG to comply with the latest code, which isn't going to solve the problems anyway.

The problem, and the only problem (other than poor maintenance), is that the NEC has major shortcomings for wiring of CGs/RV parks under article 551.

1. NEC does not have max. allowable voltage drop, it's only recommended levels. Thus CGs can have very long runs of wiring to pedestals. Older CGS (before loop-fed pedestals became the norm) can have very long runs of small gauge wire, some as small as #10.

2. NEC has too low a demand factor for multiple pedestals. When a CG has 36 or more sites, the overall demand factor (for a feeder or main service) is allowed to be as low as 41%. This just doesn't work in the summer with everyone running AC units. See table 551.73 in the NEC.

3. NEC has had insufficient numbers of 50 amp sites. Up until 2005, only 5% of a CG had to have 50 amp sites. Then in '05, they changed it to being a 20% requirement. In the 2017 edition it was upped to 40% of a CG having to have 50 amp sites.

4. The NEC doesn't not take into account all the 50 amp RVs out there today and the proliferation of 30 to 50 amp adapters. So nowadays, along come large 50 amp RVS wanting to run multiple AC units and all their other high demand appliances, pushing a 30 amp pedestal and CG wiring to it's limits.

The NEC requires a demand allowance of 3600 watts (a full 30 amps) per 30 amp site (for the first site). Up to the 2017 edition, the NEC required an allowance of 9600 watts for a 50 amp site (for the first site), and then it was increased to a full 12,000 watts (a full 50 amps @ 120/240 volts).

The majority of CGs out there are older ones that were simply built to the prevailing edition of the code at the time and RV-ers just have to live with them. There are some CGs that have been upgrading their electrical systems, including Thousand Trails that we use but that is the exception.