All building codes are based on occupant safety and meant to be used as a MINIMUM threshold. Facility owners are the ones that get to decide how much above that minimum their situation needs.
And as Mike mentioned, this is the threshold at time of original construction.
Maintenance and operations rarely have building code oversight, which is my main concern. The electrician they hire (possibly based on lowest price) to do a repair might not be familiar with RV power set-ups or minimum code requirements.
A derating makes sense, but 41% for large parks is unrealistic. I wonder how many parks end up blowing the MAIN breakers on hot days with a full park. The number of units with 3 air conditioners and residential fridges keeps growing. The low voltages are often exacerbated by in-park wiring sizes being too small. I wish that parks would overbuild above the NEC minimums, and advertise this as a perk!
We spent a number of summers visiting our kids in Michigan at a 50 year old rv park that had a many older 30 amp sites & a few upgraded 50 amp sites. During the week, with almost no one there, the voltage was adequate at 115V-120v when running very little. But on weekends, at 100% occupancy, with everything from pop up campers to large diesel pushers, the voltage would drop to under 110V with nothing running at our site. If I tried to run the air or the microwave the voltage would drop to close to 100V, which will start to damage some equipment.
Why would they allow this Mike? Campgrounds are near 100% occupied on weekends in the summer . This is also when the largest draw (air conditioners) are all running.
It’s always been like that. In fact, during the previous code cycles the NEC calculated campground load as 9,600VA (Watts) per pedestal. They bumped it up 12,000VA in 2017. I feel the demand factor is seriously in need of an upgrade for campgrounds, but that would only apply to new construction, not existing campgrounds.
Good to know there is a documented demand factor table for RV parks. Does one also exist for residential? I see panels all the time in homes with 200 amp service that have well over 500 amps of breakers on them and have wondered if this is OK.
Yes, there are demand factor tables for apartment buildings, Laundromats, condominiums, housing developments, and everything else you can imagine, including the number of circuit breakers in a residential service panel. The electric grid was not designed to turn on everything at once.
Thanks for the article, always glad to learn something new, greatly appreciate the information. That explains the voltage as it drops in the campground in summer with all of the AC units running.
All building codes are based on occupant safety and meant to be used as a MINIMUM threshold. Facility owners are the ones that get to decide how much above that minimum their situation needs.
And as Mike mentioned, this is the threshold at time of original construction.
Maintenance and operations rarely have building code oversight, which is my main concern. The electrician they hire (possibly based on lowest price) to do a repair might not be familiar with RV power set-ups or minimum code requirements.
A derating makes sense, but 41% for large parks is unrealistic. I wonder how many parks end up blowing the MAIN breakers on hot days with a full park. The number of units with 3 air conditioners and residential fridges keeps growing. The low voltages are often exacerbated by in-park wiring sizes being too small. I wish that parks would overbuild above the NEC minimums, and advertise this as a perk!
We spent a number of summers visiting our kids in Michigan at a 50 year old rv park that had a many older 30 amp sites & a few upgraded 50 amp sites. During the week, with almost no one there, the voltage was adequate at 115V-120v when running very little. But on weekends, at 100% occupancy, with everything from pop up campers to large diesel pushers, the voltage would drop to under 110V with nothing running at our site. If I tried to run the air or the microwave the voltage would drop to close to 100V, which will start to damage some equipment.
Campground electrical systems were never designed for all the power we ask them to supply.
Why would they allow this Mike? Campgrounds are near 100% occupied on weekends in the summer . This is also when the largest draw (air conditioners) are all running.
It’s always been like that. In fact, during the previous code cycles the NEC calculated campground load as 9,600VA (Watts) per pedestal. They bumped it up 12,000VA in 2017. I feel the demand factor is seriously in need of an upgrade for campgrounds, but that would only apply to new construction, not existing campgrounds.
I’m on a seasonal site . Most summer weekends I can’t use the pedestal power at all. My progressive won’t allow me too due to low voltage.
Good to know there is a documented demand factor table for RV parks. Does one also exist for residential? I see panels all the time in homes with 200 amp service that have well over 500 amps of breakers on them and have wondered if this is OK.
Yes, there are demand factor tables for apartment buildings, Laundromats, condominiums, housing developments, and everything else you can imagine, including the number of circuit breakers in a residential service panel. The electric grid was not designed to turn on everything at once.
Thanks for the article, always glad to learn something new, greatly appreciate the information. That explains the voltage as it drops in the campground in summer with all of the AC units running.