ugh... 20 amp plug on converter/charger

[turf]

opinions please.

my 80amp intellicharge charger came with a sideways 20amp pigtail plug.


i am planning on mostly using my generator to power the bus and charger, but i want to be able to plug in at pedestals with a normal 15 amp cord.

hmmm

ok, i can change the wiring to the outlet inside the bus that i was going to plug into....(rewire with 10g), change the outlet to a 20amp.

but, what about when i was planning to plug in at a pedestal? i still have to down convert to a 15amp pigtail.

can i just cut off the 20 amp pigtail on the converter and replace with a 15amp one?

[wmkbailey]

I would leave it as is. They make a 20 amp to 15 amp adapter. I have 30 amp and use the 30 amp to 15 when I'm parked in front of my parents house.

Here is a simple 20 to 15 amp adapter.

http://www.showmecables.com/product/...Fc5FMgodUx8AlA

[lornaschinske]

We just use adapters. The Class C was 30 amp and we had a 20/15 amp adapter as well as a 50 amp adapter. You should not need an adapter to plug a 20 amp cord into a 15 amp receptacle.

We have the bus set up with a 30 amp cord and carry adapters that allow us to plug into 50 amp and 20/15 amp.

Always check your adapters for damage. Especially if you are adapting down as pulling higher power thru the adapter may damage it. Before using, spray holes with a electrical silicone spray as well as after using and putting it in storage. Keeping it in a dry, waterproof container will help keep your adapter in good working order. Carry a spare.

[bansil]

Lorna a 20 plug has one pin turned 90*



15 amp



website with plug types

http://frentzandsons.com/Hardware%20...nfiguratio.htm

[turf]

i see the adapter and..... well.....

if it is always gonna be in a 15 amp receptacle, why not change the plug? doesn't the adapter rob some efficiency off the connection to begin with? if im cheating a 20amp appliance, cutting the cord and rewiring seems to be the lesser of 2 evils.

sideways plug on converter



$15 adapter
or
$15 hard wire plug?
or
upgrade bus wiring to 20A and get adapter for pedestals

[JakeC]

I don't believe the adapter will give you measurable losses, and it gives you flexibility. If you hard wire it, you may loose some flexibility. That being said, most 20 amp outlets take both plugs. Just pick one

[Redbear]

Originally Posted by turf

i see the adapter and..... well.....

if it is always gonna be in a 15 amp receptacle, why not change the plug? . . .

The purpose of the sideways pin is to prevent you from connecting a 20-amp load into a receptacle where the wiring in the wall is only sized to handle 15 amps. If you know what your loads are and accept responsibility . . .

In my camper, I got rid of the heavy 30-amp direct-wired shoreline cable that powered the DC converter plus the AC circuit breakers. We have no air conditioner or other heavy 120-volt loads to support. In its place I wired in a 20-amp piece of 12/3 rubber "cord" only long enough to reach the "mouse hole," and capped it with a used hospital-grade 15-amp plug I happened to have in my "junk box." This allows me use the converter to charge the battery, and with the right extension cord to optionally use the camper outlets for smaller loads up to 20 total amps.

Originally Posted by JakeC

I don't believe the adapter will give you measurable losses, and it gives you flexibility. If you hard wire it, you may loose some flexibility. That being said, most 20 amp outlets take both plugs. Just pick one

I am picturing "hard wiring" being cutting off the 20-amp plug with the sideways blade, and putting a 15-amp plug on end of the existing 20-amp cable. I would not put a 15-amp cable with smaller wires into the unit without seeing what the actual converter draw was.

1. A 15-amp plug on a 20-amp cable will give more flexibility, not less, as there are may 20-amp circuits with 15-amp receptacles on the end. You can still plug into dual amperage outlets, but can also plug into 15-amp outlets if you watch your loading.
2. I believe it is easier to find a 30-amp/120-volt "RV" to 15-amp adapter (I have one) than it is to find a dual-amperage one that also accepts the 20-amp sideways pins.
3. With an adapter, you may not be able to close a campground pedestal cover. While we had always boondocked, two weeks ago we camped for the first time with power. Closing the cover all the way over the 20-amp outlets 'squished' the 20-amp extension cord where it came out of the back of the straight plug. Having a "hockey puck" adapter to fit the plug into the 30-amp socket would have been worse. I am now looking for a right-angle 15-amp plug for the extension cord. The one at the HD near the campground was $12, but I put off getting it until we got home so there would be more funds for fuel and 'touristy' stuff if needed.
4. There may indeed be losses with an adapter. But worse than lost power is heat. Ever have to jiggle a plug to make a device work? If the contacts lose their springiness, there could be trouble.
For example, imagine you had a slight contact-to-contact resistance of 1/4 ohm on a 120-volt circuit when drawing the full 20 amps. The voltage drop in the adapter is (E=IxR) 20A x 0.25?, or 5 volts. The appliances run OK on 115 volts, but the ' lost' power is from turning the adapter into a 20Ax5V = 100 watt heater, and there could be a fire. Yeeowch!

Turf, I cannot advise you that it is OK for you to do what I have done. You need to read, understand, and be responsible for your own choices . . . .

[turf]

cool beans.

i accept the responsibility of my own actions here..... just trying to make an informed decision.

i agree that a 15A end makes the appliance more useful. i think that is my best option for my situation.

i just checked the interior ac wiring in the bus.

from the AC panel i have a dedicated 15amp breaker hooked to 12/2 romex which travels about 10' and terminates at a 15amp gfci outlet which is where the appliance is plugged in.

12/2 is rated at 20A
the breaker at 15A
the outlet at 15A

the small print on the charger says 1300 watts. 1300w/120v is about an 11amp draw.
i guess the charge rate is an 80A rate...

math says it should work.... i think.

watch it burst into flames 5 minutes after i hook it up

it will be a couple of weeks before i have the batteries to test the appliance. the wall is open now, so if i need bigger wire....now or never.

thanks for the input

[wmkbailey]

You will knowvsomething is wrong when the input pigtail starts to glow and get hot.

Way to go Redbear, nice write up.

[roach711]

Remember that DC amps and AC amps aren't the same measure of power.

The converter draws 80 amps DC or 960 watts (12v x 80 amps = 960 watts)

Your 15 amp AC extension cord delivers 1800 watts (120v x 15 amps = 1800 watts)

A DC watt is equal to an AC watt so I like to use watts instead of amps for DC and AC comparisons.

[JakeC]

Originally Posted by Redbear

I am picturing "hard wiring" being cutting off the 20-amp plug with the sideways blade, and putting a 15-amp plug on end of the existing 20-amp cable. I would not put a 15-amp cable with smaller wires into the unit without seeing what the actual converter draw was.

1. A 15-amp plug on a 20-amp cable will give more flexibility, not less, as there are may 20-amp circuits with 15-amp receptacles on the end. You can still plug into dual amperage outlets, but can also plug into 15-amp outlets if you watch your loading.
2. I believe it is easier to find a 30-amp/120-volt "RV" to 15-amp adapter (I have one) than it is to find a dual-amperage one that also accepts the 20-amp sideways pins.
3. With an adapter, you may not be able to close a campground pedestal cover. While we had always boondocked, two weeks ago we camped for the first time with power. Closing the cover all the way over the 20-amp outlets 'squished' the 20-amp extension cord where it came out of the back of the straight plug. Having a "hockey puck" adapter to fit the plug into the 30-amp socket would have been worse. I am now looking for a right-angle 15-amp plug for the extension cord. The one at the HD near the campground was $12, but I put off getting it until we got home so there would be more funds for fuel and 'touristy' stuff if needed.
4. There may indeed be losses with an adapter. But worse than lost power is heat. Ever have to jiggle a plug to make a device work? If the contacts lose their springiness, there could be trouble.
For example, imagine you had a slight contact-to-contact resistance of 1/4 ohm on a 120-volt circuit when drawing the full 20 amps. The voltage drop in the adapter is (E=IxR) 20A x 0.25?, or 5 volts. The appliances run OK on 115 volts, but the ' lost' power is from turning the adapter into a 20Ax5V = 100 watt heater, and there could be a fire. Yeeowch!

Turf, I cannot advise you that it is OK for you to do what I have done. You need to read, understand, and be responsible for your own choices . . . .

You have very valid points...well written!

[lornaschinske]

Originally Posted by bansil

Lorna a 20 plug has one pin turned 90*

I've been in hundreds of campgrounds since 1979 and have never seen a 90° receptacle as a 20 amp receptacle. They have the same pin set up as a 15 amp. I even have similar 20 amp receptacles inside the bus. All our receptacles are 20 amp. I have to change over to my desktop for links. You guys need to spend some time checking out the commonly used receptacles used in an RV park. They are not necesarily what is used in homes. Especially the 50 amps. This is the first campground we have been in that the pole box did not have a 15 amp duplex receptacle. It only has the RV 50 amp, RV 30 amp and a 20 amp duplex receptacle that we have an extenstion cord plugged into. It's powering the rear a/c unit.

[wmkbailey]

The 20 amp receptacles have both, so they look like a +. But the 20 amp plug does not. He could use the 15 amp plug and plug into a 20 amp receptacle and 15 amp receptacle . But a 20 amp plug will not fit a 15 amp receptacle only the 20 amp receptacle .

Either changing it over to a 15 amp plug or using a 15 amp plug adapter would work. he could use both receptacles.

[lornaschinske]

This, people, is what you will be running into in most up to date private campgrounds.


Many if not most of the smaller public and private campgrounds ( City and County parks,State Park, State Forest, NF, oddly enough TVA) are liable to only have a 30 amp plus a 15 and 20 amp duplex receptacle. The 20 amp duplex receptacles in the older cg's will look like the 15 amp (no "T") since code allows them to be connected to 20 amp (our receptacles inside say rated 20 amps and are on 20 amp breakers yet no "T"). The current NM campground is wired like this panel box shows. Our last one was not. No "T". Unless they have rewired the boxes after the last yo-yo blew out the main boxes in the middle of the campground.

Unless you intend on doing an obvious no-no... like rewiring the power pole, please use the RV standards for your plugs. I loathe the folks who rewire because the power pole is not wired up like they (re)wired their RV. We hauled someone to the hospital because they plugged into a "rewired" pedestal in a county park in Chattanooga. They were there a week with a hot skin on their older metal skinned trailer. Then it rained one day. The electricians checked every pedestal in the park while there. They spent a week fixing them. About two months later, we were there (again) and the power blew in half the park. Electricians got there and did it again. This time they caught the moron who rewired the pole. Fool admitted it (he was an electrician), got arrested and ended up paying for the electricians time spent to fix the campground (big fine... from what the rangers said, the power pole melted big time and turned black... ruined the wiring in the RV too). That's when we learned having a back up generator even when you are sitting in a campground on a fine sunny day, if a desirable option. And having "idiot proof" connections rather than an auto connect switch is good at eliminating the risk of backfeed. Rangers made every one running a genny disconnect from the power poles... seems they once had an "incident".

There are certain things that you need to set up like RVs are if you intend on staying in campgrounds that are set up for sticks-&-staples RV. So, one more time...
RV 12vDC part 1, part 2

shore power

Wiring how to's

http://www.myrv.us/electric/index.htm Read up on...
Campground service ""There are 4 receptacle configurations that you will run into in the campgrounds. From the ANSI/NEMA specification WD 6-1997"

30 Amp: The 30-amp 120-volt 2 pole 3 wire RV service (TT-30P =plug / TT-30R = receptacle). At the bottom of the article is a pdf that you can download and print out as most electricians are not used to wiring 30 amp for mobile vehicles

50 amp: The 50-amp 120/240-volt 3 pole 4 wire grounding Service (typically 14-50P = plug / 14-50R = receptacle). The 50 amp is not a specific plug/receptacle but it's the wring that is different. At the bottom of the article is a pdf that you can download and print out as most electricians are not used to wiring 50 amp for mobile vehicles.

The My RV website has some nifty info on testing the power pole BEFORE you plug your RV into it.

Mis-wiring a 120-volt RV outlet with 240-volts

For your safety (and mine) please make sure you are wiring up correctly. NEVER rewire a campground pole. If you want a "special" plug on your bus for whatever reason, go for it, just get an adapter that is wired up CORRECTLY for the power panel the rest of the traveling public is using. BTW, the park we are in does not allow adapters of any kind. You will get booted, no refunds, if they catch you on an adapter. Part is because of 50 RVs not wanting to pay the higher rate, so they use an adapter to plug into the 30 amp and try to run everything (meltdown) other part is because of mismatched wiring from folks who have their "home" receptacle and RV matched up and miswired so they have a home made adapter to plug their "RV" plug into the campground receptacle (meltdown or blows out half the park... in summer.... during a heat wave... and they LEAVE while the rest of us suffer until the power is fixed).

We do run adapters. We bought an adapter that allows us to plug our TT30 plug into a 50 amp RV wired receptacle in an RV/ mobile home park. We have an adapter that will allow us to plug a TT30 plug into the 15/20 amp receptacles that are (were?) found in Georgia Veterans State Park and Harrison Bay State Park. No A/C just fans while on single 20 amp so that isn't something we like to do in the hot summer. We do not like running adapters (melted one just running a dorm frig & dorm freezer plus nothing else... we were told to change sites as the panel box was very hot) and really rarely use one long term (exceptions was in a GA state park where we lived for several months one winter and in TX RV/Mobile home park for 6 months... we kept feeling the power connections & cord to feel if it was getting hot). For the bus, if we had to be long term (year or longer) we would simply build a new power cord and wire it into the bus or set up a plug in substitution. But the odds of us having to do that are pretty low. Our next long term spot should be our own and it will have 30 amp and 50 amp (future rental?) receptacles... wired correctly.

We have been luckier than others we have met in that we have never plugged into a receptacle and immediately suffered a melt down. Only power damage we have suffered from (except the melted adapter) was from low power in a park. I lost a small convection/microwave in a state park. But I have lost other appliances at home from brownouts so I don't really count that.

[Redbear]

Originally Posted by JakeC

. . . most 20 amp outlets take both plugs. . . .

Mea culpa, mea culpa, mea maxima culpa . . .
I had always assumed that the receptacles with the "T" neutral were called 15/20 amp, and that the ones that ONLY take the sideways ones are called 20 amp. Nope. I was in HD yesterday getting my right-angle plug, and both the "T-slot" and the sideways-pin-only receptacles are both called just plain 20-amp. So I checked the NEMA chart this morning, to see if they had different designations. Nope. Both types are considered NEMA 5-20. Soooo . . . . .

A 20-amp receptacle will always take a plug with a sideways pin, but it may have a "T-slot" or it may not. Therefore a 15-amp plug either will fit into a 20-amp receptacle or it will not. AAAaaarrrgh!

[lornaschinske]

Now I have "Fruitcakes" stuck in my head........

This is why you carry adapters. We have only had to buy one adapter from a campground. We used for that one campground and never again. We paid roughly triple what it would have cost us at a walmart if we had known where the closest walmart was. The campground was well stocked with those particular adapters. Coincidence? I think not! If you are in enough different campgrounds, you are likely to run into one that takes an oddball/adapter. The image of the RV Park panel box is pretty typical although most we have run into also include 15 amp duplex along side the 20 amp which is not always able to take the 90° pin. Even in the public parks we have stayed in 30 amp seems to be the most consistent. When we do Das Mel's skoolie, it will be 30 amp and she can buy a 50 amp adapter for mobile home parks if she needs it.

[family wagon]

So: it seems to me that the type with the T on the neutral blade, or with the horizontal/90-degree neutral blade, both are rated for 20 amps. The former is convenient because it also accepts 15 amp plugs; bless the campground people who elect to install that type. Those that feature only parallel blades are only rated for 15 amp, even though NEC allows at least in some circumstances for these 15 amp receptacles to be wired behind a 20 amp breaker. At least I personally haven't seen a parallel-blade-only (ie, not dual-mode T type) that was rated for 20.

The point of it all is as mentioned by Redbear: every connection will experience some heating. Heat will cause the metal in the connector to relax, loosing the connection and causing further heating, until finally one day the thing melts or burns. If one will be pulling 20-ish amps then it's a Good Idea (tm) to use 20-amp plugs and receptacles -- ie, don't draw 20 amps through that 15 amp receptacle and plug that are behind a 20 amp breaker.

[Redbear]

Originally Posted by family wagon

. . . If one will be pulling 20-ish amps then it's a Good Idea (tm) to use 20-amp plugs and receptacles -- ie, don't draw 20 amps through that 15 amp receptacle and plug that are behind a 20 amp breaker.

I disagree. If the breaker is 20 amps, then the wiring should be wired (with 12 gauge wire) for 20 amps. Not everyone will install a "T-neutral" receptacle on a 20-amp circuit, but will just wire in a "standard" outlet. It is more convenient to put a 15-amp parallel-blade plug on your 12-gauge, 20-amp extension cord. And it is safer than using a 15-to-20 amp adapter.

Just be smart, control your loads, and don't draw 20 amps on a circuit truly wired for only 15 amps. The different-shaped plug is to help keep the average Joe from doing just that. The 15-amp receptacles are so they will be chosen for appropriate circuits, not because that is the limit of their load capacity.

[turf]

i hope next week to have that wall panel off. i think i'm going to try and change the receptacle to a 20A cross blade. i dont think the appliance will pull that many amps. my math before was 11amp draw for the charger. i think i will leave the breaker at 15A, unless it start popping.


kk... new electric safety question

i want to install a house oven in the bus, rated at 4000 watts.

my gen should supply enough electric. (12.5kw split phase 120/240v)
can i swap a 20A circuit breaker for a 40A and put in 8g line to the stove?

right now the panel has 3 - 20A 240 breakers in it that feed 3- 3000watt heaters. i was gonna swap one of the heater circuits for the stove.

[Redbear]

4000 watts seems a little light for an oven. Is it a separate oven, or oven/cooktop combination?

A more typical residential installation for a combination range is a dual 50-amp breaker with #6 wires. But that is for cooking Thanksgiving dinner with the main course in the oven and four "burners" on the top going full tilt all at once.

If it is one of those wall-mount separate ovens, then your calculations may be right on.

To answer the main part of your question: yes, it is common to remove an unused breaker of one size, and install a replacement breaker of another size in its place. Just be sure not to overlook two things:

1 - the rating of the panel. While a 100-amp panel may have branch circuits that add up to 200 to 400 amps if everything was playing at 100%, the actual total electrical draw in use needs to be within the rating of the panel.

> If you are powering the bus off of a 50-amp 240-volt campground pedestal, or your 12.5 kW genny tapped for 240 volts at 52 amps per side, then obviously using a small 30-amp rated panel with 40 amp breakers is a bad thing.

2 - the rating of all parts in the supply side feeding the panel. The wiring and connectors to the genset or pedestal and the main disconnect all need to be able to handle all the loads in use on the output side of the panel.

So, from your description, if the rating on the oven is correct, it sounds like your plan is OK.

Disclaimer: I have not seen your bus, generator, or oven. I am not a lawyer, nor do I "play one on TV." And I did not stay at a Holiday Inn Express last night. Ask your doctor if you have been to a country where fungal infections are common. Do not spindle, fold, or mutilate. Void where prohibited by law. Your mileage may vary. Have a nice day.