Community Forums

phil57 · 05-01-2019, 09:56 AM

A quick question. I have a friend (no really I do) that might have plunged his 2017 London Air into a 30 amp plug that most likely is wired for a dryer. He now has no ac power. The fridge and everything else works but only on battery power. He also has no surge protector. I know don’t bother saying how wrong this is he is well aware. Question is aside from the transfer switch and the 50 amp bar fuse what would keep it from getting power? What can we check. Tech support at Newmar says it’s the transfer switch. Nothing smells burnt and we have reset everything. Any ideas?

twinboat · 05-01-2019, 10:18 AM

Is it a 30 amp or 50 amp RV ?
Did he home make an adaptor ?
Fridge runs on batteries or gas ?

If it has an inverter, check for popped push button breakers.

Do things work on generator power ?

A proper wired 4 blade 30 amp outlet can run a 50 amp RV.

4 blade outlets are 120/240 volt outlets. That what a 50 amp RV uses.

If its a 3 blade 30 amp outlet and a 30 amp RV, then thing can go wrong fast.
A 3 blade 30 amp dryer outlet is 240 volts only and a 30 amp RV is 120 volts only.

puttin · 05-01-2019, 10:28 AM

Do you have a meter or test light? Find a 50 A source you can connect to the rv (verify it's correctly wired first), then probe the input side side of you ac panel to verify voltages. If non or just on one leg- you'll know there's a problem between there and power cord. Here's an over view:
RV Electric

And this:

phil57 · 05-01-2019, 10:43 AM

The London air is 50 amp. I’m at there house and I’m plugged into 50 amp that works as it should. He thought he would just run his on 20 amp as he is in a climate controlled garage. When the charger came on it blew the 20 amp breaker. In his sleepy state he thought he would try the 30 amp plug. It is wired as a 220 not wired correctly for a RV. We know that. We have at this point shut everything down and plugged into the good 50 amp with no luck. We get no AC power either from shore or generator. I have checked the 50 amp bar fuse and it’s good. We have the inverter working but the batteries are dying. We know he messed up plugging into the 30 amp but what do you think is blown up. The transfer switch has no burnt smell and there is no board that I could see in it. The fridge is a residential and it runs on battery power.

Milford 47 · 05-01-2019, 11:08 AM

Quote:

Originally Posted by phil57

A quick question. I have a friend (no really I do) that might have plunged his 2017 London Air into a 30 amp plug that most likely is wired for a dryer. He now has no ac power. The fridge and everything else works but only on battery power. He also has no surge protector. I know don’t bother saying how wrong this is he is well aware. Question is aside from the transfer switch and the 50 amp bar fuse what would keep it from getting power? What can we check. Tech support at Newmar says it’s the transfer switch. Nothing smells burnt and we have reset everything. Any ideas?

Check the dog bone or plug he had to fabricate to use, that will tell the story of what if anything happened

oscarvan · 05-01-2019, 11:19 AM

If I read your post correctly he applied 240V to...... just about everything.

So, the most sound advice above is from puttin.

Turn ALL AC breakers off.... Plug into 50A, or PROPER 20/30, or start the generator. Take the cover off the AC breaker panel and check for 120V at each 50A supply breaker and neutral/ground.

If not present look at the transfer switch. I suspect it's fried.

If you're lucky and it's working and you have 120V at the panel on BOTH legs.... turn on breakers and check each circuit and what's on it. GFI's may be blown. If appliances were not running they may be OK......

Once circuit at a time. Electrical diagnosis is a process of elimination.

Unplanned Tourist · 05-01-2019, 11:22 AM

Sounds like the transfer switch all right. Check the voltage on the terminals going in when plugged into the 50 A MH outlet. Should be 120 V on 2 legs, and 240 V across the 2 120 hots.
Then check output side of the transfer switch. It should be the same.
If you say there is no power when the genset is running, then likely internals of the transfer switch are history.
Hope that helps.
Happy Glamping.

Old-Biscuit · 05-01-2019, 11:30 AM

Remove cover on transfer switch
Plug into 120V AC 50A power source
With voltmeter verify that the shore power side is HOT (L1 & L2)

Then check if AC Out to main panel is HOT
NO..transfer switch is bad
YES...then need to verify you have 120V AC to Main AC Panel BUS Bars
Should also do SAME test using Generator

Think you will find transfer switch is bad.......relays/contacts burnt

phil57 · 05-01-2019, 11:33 AM

We checked and 99% sure it’s the transfer switch. I believe he dodged a expensive bullet. We found a transfer switch and will grab it today and install. I would have expected a burnt smell but didn’t. On my Motorhome I have a replaceable circuit board that saves a lot of rewiring. I’ll post what we find out. Thanks for the input.

twinboat · 05-01-2019, 11:54 AM

The 240 may have quickly burnt the relay circuit board before any of the contactors closed.

If that's the case, he is lucky.

Solo_RV_Guy · 05-01-2019, 11:59 AM

I'm pretty sure he mis-wired (or used the wrong connector) his home made dog bone.

The 30 amp RV plug is designated at "TT-30" (travel trailer) and is for 120 volt service ONLY. The 30 amp, 240 volt plug for electric clothes dryers comes in 2 flavors - the NEMA (Nat'l Electrical Manufacturers Assn) 10-30 (old style 3 pin, no long acceptable under Code) and the new (since before 2000) NEMA 14-30.

From Wikipedia:
"The appearance of this plug (TT-30) is sometimes confused with a NEMA 10 connector, rated for 240 V, but the NEMA TT-30 is a 120 V device. The hot and neutral blades are angled at 45° from vertical and 90° to each other, unlike NEMA 10 devices (where the angles are 30° and 60° respectively), also the plug is slightly smaller than a NEMA 10 and larger than ordinary 5-15P plugs. The ground pin is round, like those on straight-blade NEMA grounding devices. Referring to the picture, the orientation is the same as the NEMA 5 plug and receptacle, with the neutral blade on the lower right."

oscarvan · 05-01-2019, 12:31 PM

Quote:

Originally Posted by Solo_RV_Guy

I'm pretty sure he mis-wired (or used the wrong connector) his home made dog bone.

The 30 amp RV plug is designated at "TT-30" (travel trailer) and is for 120 volt service ONLY. The 30 amp, 240 volt plug for electric clothes dryers comes in 2 flavors - the NEMA (Nat'l Electrical Manufacturers Assn) 10-30 (old style 3 pin, no long acceptable under Code) and the new (since before 2000) NEMA 14-30.

From Wikipedia:
"The appearance of this plug (TT-30) is sometimes confused with a NEMA 10 connector, rated for 240 V, but the NEMA TT-30 is a 120 V device. The hot and neutral blades are angled at 45° from vertical and 90° to each other, unlike NEMA 10 devices (where the angles are 30° and 60° respectively), also the plug is slightly smaller than a NEMA 10 and larger than ordinary 5-15P plugs. The ground pin is round, like those on straight-blade NEMA grounding devices. Referring to the picture, the orientation is the same as the NEMA 5 plug and receptacle, with the neutral blade on the lower right."

Well, since his buddy was able to plug into the dryer outlet half asleep we can assume he had the old style....

A.R.F. · 05-01-2019, 01:49 PM

Quote:

Originally Posted by phil57

The London air is 50 amp. I’m at there house and I’m plugged into 50 amp that works as it should. He thought he would just run his on 20 amp as he is in a climate controlled garage. When the charger came on it blew the 20 amp breaker. In his sleepy state he thought he would try the 30 amp plug. It is wired as a 220 not wired correctly for a RV. We know that. We have at this point shut everything down and plugged into the good 50 amp with no luck. We get no AC power either from shore or generator. I have checked the 50 amp bar fuse and it’s good. We have the inverter working but the batteries are dying. We know he messed up plugging into the 30 amp but what do you think is blown up. The transfer switch has no burnt smell and there is no board that I could see in it. The fridge is a residential and it runs on battery power.

I just had a similar problem. My inverter outlets worked on shore power,
generator power and on batteries. My batteries would not take a charge. I smoked a relay on my charging circuit board in my Xantrex inverter. He may want to check that also. There maybe a blown fuse in the inverter. Just a thought.

cavie · 05-01-2019, 02:07 PM

Quote:

Originally Posted by phil57

The London air is 50 amp. I’m at there house and I’m plugged into 50 amp that works as it should. He thought he would just run his on 20 amp as he is in a climate controlled garage. When the charger came on it blew the 20 amp breaker. In his sleepy state he thought he would try the 30 amp plug. It is wired as a 220 not wired correctly for a RV. We know that. We have at this point shut everything down and plugged into the good 50 amp with no luck. We get no AC power either from shore or generator. I have checked the 50 amp bar fuse and it’s good. We have the inverter working but the batteries are dying. We know he messed up plugging into the 30 amp but what do you think is blown up. The transfer switch has no burnt smell and there is no board that I could see in it. The fridge is a residential and it runs on battery power.

What are you calling a "50amp bar fuse"? the 50 amp main breaker in the RV? It's a 2 pole circuit breaker not a fuse. Did you take the cover of the panel and use a volt meter?

How did you check it? Did you turn it off then back on?