Decision on 30A versus 50 amp inlets

[jeremyHB]

Hello, I am renovating a 1978 Airstream Argosy Minuet and about to start rewiring, and am wondering whether i should just go ahead and make the inlet 50amp, as it was previously only 30A but may need the extra power. thoughts, JeremyHB

[azflycaster]

The most popular reason to upgrade to 50 amp is adding a second AC unit. I don't think that would be practical on your size trailer. What do you see as a need for the additional amperage?

[waninae39]

30A is more common than 50A
unless you need two Ac units, go 30A

[Isuzusweet]

I'm renovating a 78 6.7m Minuet myself and 30 amp will be enough. 50 amp wire is a lot heavier.
Coosa subfloor going into mine right now.
Goodluck with your reno
Cheers
Sidekick Tony

[Atomic_13]

Agree with the above. Unless you have an unusually high energy need 30A makes sense. Also, the installation cost rises quite sharply with 50A (6AWG, larger breakers, etc). I’d suggest you estimate how many amps you’ll draw before moving forward. For example, it would be unusual to use all five of these at the same time:

8A microwave
10A water heater
13A air conditioner
8A furnace fan
10A hair dryer

Other items:
? Converter
? Refrigerator
? Electronics charging (laptop, etc)

Another option is to consider using a 30A system but install a hybrid inverter that will convert battery power into AC if you temporarily exceed 30A. For example, Victron’s Multiplus line does this.

[SilverPal2]

The 50amp connector and circuitry are intended to be used in a 220V system therefore unless you plan to do a 220V conversion you stay with the 30amp connector

[tjdonahoe]

Originally Posted by jeremyHB

Hello, I am renovating a 1978 Airstream Argosy Minuet and about to start rewiring, and am wondering whether i should just go ahead and make the inlet 50amp, as it was previously only 30A but may need the extra power. thoughts, JeremyHB

...go with 50

[pmclemore]

I removed my second ac and had the rig converted from 50 to 30. I hated that big-a 50amp cable. (And the ac over the bed, too).

Pat

[tbashin]

Originally Posted by tjdonahoe

...go with 50

Agree. Go 50A and you can run more stuff at once. One less worry down the road.

[mikeoxlong]

If you plan on any winter camping the extra ampacity could e handy with electric heating.

[Tater]

I would go 50. If you want to run a microwave and a/c at the same time 30 probably won't do it especially of an converter for batteries and/or refrigerator is on at the same time. You can always use less with 50 amps (12,000 watts) available than 30 amps (3,600 watts) but with 30 you can't use more.

[bibbs]

Are you camping? Or bringing your house with you. At 230 volts 50 amp you are close to 4X what you will use. Unless you are going to have a jacuzzi. I often just use a 20 amp service. If I don’t need air conditioning.

[gklott]

Originally Posted by SilverPal2

The 50amp connector and circuitry are intended to be used in a 220V system therefore unless you plan to do a 220V conversion you stay with the 30amp connector

Agree. You should only use a 50A inlet if you are rewiring the entire AC system from a 240/120 VAC load center. Otherwise, stay with 120 VAC 30A inlet and load center. 30A seems plenty good for your trailer size.

Recommend looking through these before you start: NFPA 70 2020 edition, National Electric Code, Article 551 and NFPA 1192 2018 edition, Standard for Recreational Vehicles.

For the inlet itself, we are extremely pleased with our SmartPlug.

73/gsu

[DKB_SATX]

Originally Posted by SilverPal2

The 50amp connector and circuitry are intended to be used in a 220V system therefore unless you plan to do a 220V conversion you stay with the 30amp connector

While I agree that the OP doesn't need 50A service for the Minuet, your reasons here are misleading. While the 50A shore power inlet makes 240v AVAILABLE (the difference between the 2 "hot" legs is nominally 240v) RVs with 50A shore power are generally wired as 2 legs of 120v 50A service for a total available power of 100A at 120v. All appliances and systems in a 50A Airstream are 120v, for example.

[tjdonahoe]

Originally Posted by bibbs

Are you camping? Or bringing your house with you. At 230 volts 50 amp you are close to 4X what you will use. Unless you are going to have a jacuzzi. I often just use a 20 amp service. If I don’t need air conditioning.

.......everything in the As is 110 volt...1 ac and water heater with microwave is cutting it very close for 30 amps...

[jeremyHB]

Originally Posted by Isuzusweet

I'm renovating a 78 6.7m Minuet myself and 30 amp will be enough. 50 amp wire is a lot heavier.
Coosa subfloor going into mine right now.
Goodluck with your reno
Cheers
Sidekick Tony

Thanks so much for info, I think that I am sticking with 30amp. I am also considering the Coosa board for my subfloor so it was great to see your tests.
Thanks,
jeremy

[Al and Missy]

Originally Posted by SilverPal2

The 50amp connector and circuitry are intended to be used in a 220V system therefore unless you plan to do a 220V conversion you stay with the 30amp connector

There is no conversion other than adding another wire between the shore power input and the breaker panel and upgrading that wiring to a larger gauge. All that wiring is heavier, but it is usually very short. In my trailer it is is less than 6 feet. Everything past the breaker panel remains the same, i.e 15 and 20 amp breakers and supporting wire.

That said, unless OP plans some heavy power consumption like 2 ACs or residential stove-top/oven, 30A should be sufficient.

It is possible, however, to overload a 30A service by using AC, water heater on electric, microwave and converter, so some power management may be needed with 30A that is not with 50A.

Al