Alladin says open ground

[Bill Lampkin]

30a ok, 50a says open ground. Sending from my phone, abbreviated text

[Steve Huber]

Bill,
 What are you plugged into? Since both 30A & 50A require neutral and ground it would seem that the problem is outside the RV. Otherwise it might be in the transfer switch box where the Aladdin senses power supply inputs.
Steve

[Joel Ashley]

I’ve run into a few faulty 50amp outlets at RV parks.  Steve’s advice to first suspect yours is spot on.  You should ask (competent) park personnel to test your post.  They may have to call an outside electrician or move you to another spot.

Joel

[David T. Richelderfer]

We ran into this phenomenon one time. It was at the little and free RV park behind the Silver Dollar Inn at Haugan, MT.  The power post I plugged into was bad and the surge protector would not accept its power.  Our coach's Aladdin did not get to see the power at all because our surge protector stopped the power refusing to allow the power to pass on into the coach.  We tried a couple of other power posts and they all were bad.  So we pulled into a more secluded RV parking spot in the RV park and used our onboard generator.

[Steve Huber]

Build yourself one of these to verify power prior to plugging in and save yourself some headaches. Email me if you want the diagram & parts list.
Steve

[Joel Ashley]

Some years ago I made one like Steve's, but kudos to his that is less complicated.  I just followed instructions from some website, and modified it to what I thought was a better setup.  Either one will provide warning before hooking up to any new post, if you remember to use it.  Which is why I store mine in a container next to my cord reel.

Joel

[Bill Lampkin]

Thanks! Issue was bad power at two campgrounds. Question is; how so as 30a and 50 amp share a common ground wire at the pedestal.

[Bill Lampkin]

I,ll take a. Crack at it. Ground is split (jumpered) between the 30a and 50a receptacles.Now, how does the Aladdin figure this out?

[Bill Lampkin]

Two different receptacles, one with ground (30a), one without (50a). Mystery solved.

[Keith Moffett Co-Admin]

Bill
We also have had bad power at the post.  So bad in fact that it burned my surge protector,  literally set fire to it. 
I rebuilt that surge protector and now just use it to test the post before plugging in even though our coach has one built in.  If it teste bad at the post and fries my old surge protector its no loss but we dont lose the power switch in the coach.

[Lee Welbanks]

Just use a multimeter to test the park shore power, 30 and 50 amp. There are plenty of videos on Youtube of how do this test.