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1956elli · 07-26-2019, 09:23 AM

2005 Land Yacht 30 ft 50 AMP service

30 amp trips after approx. 5 min of cooling 85 outside temp, will run longer in cooler temp - front ac unit

20 amp does not - rear ac keeps cooling

When on shore power AC runs no problem

Would replacing breaker on generator be the best place to start as to fixing problem

uncle_bob · 07-26-2019, 09:30 AM

Hi

Best bet is the A/C unit is not in good shape.

Bob

1956elli · 07-26-2019, 11:32 AM

Thanks Bob

Having "limited" knowledge on electrical and how it works - I shall ask

If it does not trip the breaker on the inside panel when attacked to shore power why would it then trip the generator breaker when not using shore power - both 30 amp

Wolfe · 07-26-2019, 11:48 AM

a clamp on amp meter will tell the tail, or you can PPC it, (pro parts changer)

92landyacht · 07-26-2019, 11:58 AM

Make sure that the generator is putting out the correct voltage. Low voltage can cause the AC to run less efficiently and use more current. Many AC's have a low voltage alarm but not all.

When you say the 30 amp breaker blows but not the 20, than I'm assuming you're talking about the breakers directly on the generator. Is this correct?

1956elli · 07-26-2019, 12:45 PM

Yes the 30 on the generator the 20 does not trip

It will run with both AC units cooling but the front AC which is on the 30 will trip after about 5 to 10 min

1956elli · 07-26-2019, 12:50 PM

More info - I turn the 20 off at the generator and the 30 will still trip after the same time period

No appliances on in the coach, no lights

bibbs · 07-26-2019, 12:59 PM

Is the fridge set to gas? Also try unplugging the charger/converter. Does the water heater also use 120v?

92landyacht · 07-26-2019, 02:36 PM

Turning that on or off will have no effect. You need to still verify voltage and current on that line. You'll need a digital multi-meter that has a current sensing clamp. You can pick them up pretty inexpensively now. Even Home Depot has them for around $59.00:

https://www.homedepot.com/p/Klein-To...L210/207144572

All you have to do to make a current reading is to put the clamp around the hot wire (black) and set the scale to read AC Amps. No need to probe anything. Voltage reading is easy as well. Set the meter to read AC volts ~ and then probe a socket that's on that breaker. The meter will auto range and give you an accurate reading.

I personally wouldn't travel without one.

1956elli · 07-26-2019, 03:42 PM

Thanks for all the info - something to do tomorrow and somethings else to buy
Yall have a good weekend

92landyacht · 07-26-2019, 03:47 PM

Quote:

Originally Posted by 1956elli

Thanks for all the info - something to do tomorrow and somethings else to buy
Yall have a good weekend

Welcome to the world of owning an RV. Seems like there's always something to do or buy.

rmkrum · 07-26-2019, 03:56 PM

Yeah, stay away from the “What did you get for your Airstream today” thread. Gets me in trouble every time.

batman · 07-26-2019, 05:53 PM

Just a quick couple questions.
What make and model of generator are you using?
Have you used this generator before with this trailer and both AC's running?

-Dennis

1956elli · 07-26-2019, 07:34 PM

Purchased this past February and yes we ran the generator and both AC units for about 20 min. but it was a lot cooler then and no problems

Other trips I have only used shore power because it was cool enough while driving with dash AC

ONAN 5.5HGJAB-901C Per "sticker" 45.8 Amps 5.5 KW

Hay - I have plenty of experience buying STUFF - also got boat & WIFE

Al and Missy · 07-26-2019, 08:00 PM

Is your generator gasoline or propane? The gasoline version has a mechanical governor that may need adjustment. Also the carburetor has an altitude adjustment.

Al

dadstoy · 07-26-2019, 08:02 PM

If the A/C is working fine on shore power, then I'm going to also guess that the GenSet is not putting out the correct voltage. See the post I wrote below...

http://www.airforums.com/forums/f311...ml#post2263689

uncle_bob · 07-27-2019, 07:00 AM

Hi

Never rule out a defective breaker

The "measure it" advice is really the only way to go. Otherwise you just start randomly swapping parts out. That gets expensive if the A/C is the first thing you swap ....

One thing to watch for as you go shopping:

Clamp on amp meters come in various ranges and types.

Most are designed to look at a whole house at once. Some have a 400A range and that's it. You will *never* need to measure 400A of AC current in an RV.

If the "bottom end" of that scale is 4A, that's not real good. Take a look at how it does on low currents.

You can get AC only gizmos and they have been around for a *long* time. I have a couple with ... errr ... analog needle displays .... yikes !!! These days you can also get ones that will do both AC *and* DC. For an RV, that is a very handy thing. You are just as likely to be playing with 12V DC as with 120V AC. The same "current range" thing applies here as well.

A handy accessory for the AC version is a little inline plugin device. It lets you put it inline with an appliance. You can then clamp on to the (now accessible) lines to the device. The really cool ones have a 10X side that helps with the range on the amp meter. Even the fancy ones are dirt cheap. Yes, you can also make one from scratch.

If you go crazy, you can indeed spend a lot of money on this stuff. One example:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

(Yes, there's one sitting in the drawer over under the fridge. There's also a digital oscilloscope and a 5 1/2 digit DVM in the wardrobe closet .... crazy indeed ....)

Bob

lsbrodsky · 07-27-2019, 08:11 AM

"A handy accessory for the AC version is a little inline plugin device. It lets you put it inline with an appliance. You can then clamp on to the (now accessible) lines to the device. The really cool ones have a 10X side that helps with the range on the amp meter. Even the fancy ones are dirt cheap. Yes, you can also make one from scratch."

Thanks, I never knew those things existed although the use seems limited, first to something in a normal AC circuit limited to 15 amps. Seems like I would use my clamp-on more for stuff that is not or does not plug in to a normal outlet.

Larry

uncle_bob · 07-27-2019, 08:16 AM

Quote:

Originally Posted by lsbrodsky

"A handy accessory for the AC version is a little inline plugin device. It lets you put it inline with an appliance. You can then clamp on to the (now accessible) lines to the device. The really cool ones have a 10X side that helps with the range on the amp meter. Even the fancy ones are dirt cheap. Yes, you can also make one from scratch."

Thanks, I never knew those things existed although the use seems limited, first to something in a normal AC circuit limited to 15 amps. Seems like I would use my clamp-on more for stuff that is not or does not plug in to a normal outlet.

Larry

Hi

Indeed the standard cheap gizmo is a "plug into a 15A outlet" sort of thing. The main use is checking things like fans, coffee grinders, wall chargers, .... to see how much they pull. Comes in handy when you are trying to sort out what will and won't work (and in what combinations) with your inverter.

Since all you are doing is putting a few coils of wire "inside" the clamp, there is no reason you can't use the same trick in other settings. You *do* need to have enough wire to make the loops and it has to be flexible enough.

Bob

kpm · 07-27-2019, 09:05 AM

Quote:

Originally Posted by uncle_bob

[...]
A handy accessory for the AC version is a little inline plugin device. It lets you put it inline with an appliance. You can then clamp on to the (now accessible) lines to the device. The really cool ones have a 10X side that helps with the range on the amp meter. Even the fancy ones are dirt cheap. Yes, you can also make one from scratch.
Bob

Could you give an link to a decent one online?