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intermittent electrical problems

Yahoo Message Number: 55710
Hi There,

I have begun to experience intermittent electrical power problems in my coach. While plugged into 50amp shore power, I suddenly lost 110 devices throughout the coach. I heard some clicking noises around my interior sensor panel, then the power came back on about 20 mins later. During the 110 power loss, the panel indicating battery strength visibly dropped from 100% to 70%. I turned off the inverter outside the coach, and I had 110 power again, for about 12 hours. The whole scenario repeated itself, power restroed, and it lasted 20 hours before going through the same cycle.
I started the generator, and had no power problems, the batteries recharged, and when I shut the generator down, the shore power provided the 110 power. I changed the surge guard, same thing happened. I checked the power source at the plug in, it is putting out properly.
So, I'm stumped....Does anyone have any suggestions or similar experiences? I had a mobile tech out and he couldn't identify the problem as its so intermittent.
I'm open to any and all thoughts,
Thanks,

Jerry Keller

2006 Allure #31347

Re: intermittent electrical problems

Reply #1 –
Yahoo Message Number: 55713
Jerry, I would start with the path that power enters and moves through the coach. You mention the generator seem OK, so move on to shore power flow. If everything checks OK at the power post, (I assume you have been plugged in a while and this problem is new) does the serge protector cut off power? Are you using any large draw appliances, like electric heat pumps or washer / dryer that may be generating heat in the wiring? It is common for one 120v receptacle somewhere to have a loose wire which will cause the surge protector to cut out. Next is the transfer switch. All the wire lugs tight there? Next check the wiring on the inverter. Not sure about the clicking noise at inside panel. If this happens when power is restored, could be the energy management panel returning power to the circuits. My guess is, if you can narrow down the reason for power cutting off, the battery charge will be OK.

Dave 07 Inspire 52060

Re: intermittent electrical problems

Reply #2 –
Yahoo Message Number: 55733
A couple months ago I experienced a similar AC power problem. After a lot of poking around I discovered that two GFI's were faulty. I replaced them and all was okay.

Mel Shapiro
LEXA 6177

Re: intermittent electrical problems

Reply #3 –
Yahoo Message Number: 55734
Jerry,
1. I would bet the SurgeGard has gone bad OR the inbound power at the post is dropping to low voltage causing the SurgeGard to turn off. You can check by bypassing the SurgeGard with the key on the front panel.

2. The above is causing your coach to run off the inverter which will draw down your batteries. Since your batteries are old, the draw down will happen fast. My OEM batteries only lasted two years.

3. The clicking sounds you hear are the transfer switch changing between shore power and internal power. Nothing to worry about.

4. The generator bypasses shore power and the inverter so everything will work and the batteries will charge.

Al

2006 Allure Hood River #31440

Re: intermittent electrical problems

Reply #4 –
Yahoo Message Number: 55738
Hello to all who provided thoughts and guidance on my intermittent power problems.
An electrician finally narrowed it down to my transfer switch. I have one ordered, he will put it in as soon as it arrives, and hopefully all will be well. Right now the coach is sitting with all of the 110 appliances off, the refer is on LP, and I have a trickle charger hooked up to the house batteries maintaining a charge. The new transfer switch should be here in a couple of days.
Thanks again to all of you who shared with me insight and ideas about how to diagnose and correct this issue.
Best,

Jerry Keller

2006 Allure 430 #31347

Re: intermittent electrical problems

Reply #5 –
Yahoo Message Number: 55747
Not a good idea to by pass the surgeguard until one knows what the problem is.

Chuck & Mary B

Shelby Dog, Miss Kitty, Mr Lucky Cat

Re: intermittent electrical problems

Reply #6 –
Yahoo Message Number: 55752
Jerry,

Glad you found it. It is an extremely simple matter to bypass the transfer switch and have shore power while you are waiting for the new one. I should mention that I did this and it turned out to be the surgeguard.
Others have told you about the Progressive products. Go to their website as they sugggested: for openers, instead of idiot lights you have a digital readout with ten fault codes. These units are modular and parts are field replaceable by owner, etc.

Rich

Re: intermittent electrical problems

Reply #7 –
Yahoo Message Number: 55754
Hi Jerry,

I do not understand why your electrician did not suggest that he wire around the transfer switch since it has to come out anyway.

Chuck & Mary B

Shelby Dog, Miss Kitty, Mr Lucky Cat

Re: intermittent electrical problems

Reply #8 –
Yahoo Message Number: 55758
I would expect that the clicking sounds (not one thump) is the EMS ramping up or down its load sharing relays with its multiple indicator lights, when the power changes over.

Herb

2007 Allure #31466 (SOLD)

Re: intermittent electrical problems

Reply #9 –
Yahoo Message Number: 55759
Quote
I would expect that the clicking sounds (not one thump) is the EMS ramping >up or down its load sharing relays with its multiple indicator lights, when >the >power changes over.
Are any of the EMS relays fast enough to respond in one nanosecond???

TF

Re: intermittent electrical problems

Reply #10 –
Yahoo Message Number: 55777
Hi T Boone,

Go to www.progressiveindustries.net for the information you are asking. The unit is microprocessor controled for the needed protection. Its not the operation of any given relay, but the release of the relay.

Chuck & Mary B

Las Vegas, NV

Shelby Dog, Miss Kitty, Mr Lucky Cat

Re: intermittent electrical problems

Reply #11 –
Yahoo Message Number: 55780
Quote
Hi T Boone,

Go to www.progressiveindustries.net for the information you are asking.
The unit is microprocessor controled for the needed protection. Its not >the >operation of any given relay, but the release of the relay.
Common sense would tell anyone that a mechanical relay cannot respond/open in "less than one nanosecond". Thus, IF the neutral line opens *after* the unit has connected power, items in your coach will be momentarily be exposed to as much as 220V. Many if not most devices only designed to be operated on 120V will be FRYED when only momentarily exposed to 220V.

TF

Re: intermittent electrical problems

Reply #12 –
Yahoo Message Number: 55781
TBonne

Would you kindly explain how an open neutral exposes any 110 volt appliances to 220 volts.

Don Seager

2004 Allure 31046

Re: intermittent electrical problems

Reply #13 –
Yahoo Message Number: 55783
The EMS relays I am referring to is when you are on 30A (or it thinks you are) -- it manages any potential overload by shedding up to five loads -- rear A/C compressor, front A/C compressor, Hot Water Heater, Washer/Dryer, and A/C fans (not in that order) -- to keep you under 30 or 20 amps. In some cases, when power is applied, it connects the load over a couple seconds -- hence the multiple clicks.
FYI, Dip switches sets the order that load is shed or added. Mine were not set correctly to match the labels.
When it sees a 30A load, it sheds the first load, and will not restore it until the current used by other circuits decreases for around two minutes.

Herb

2007 Allure #31466

Re: intermittent electrical problems

Reply #14 –
Yahoo Message Number: 55787
Quote
TBonne

????

Quote
>Would you kindly explain how an open neutral exposes any 110 volt >appliances to 220 volts.
I'll do better than that. I'll illustrate it. Plug your coach into a 50 amp receptacle and then disconnect the neutral connection to the receptacle. The illustration will be dramatic and you won't forget it!!;-))
TF

Re: intermittent electrical problems

Reply #15 –
Yahoo Message Number: 55790

TF Basically, the neutral is the reference wire for the voltage lines. You have two hot wires which are 120v to neutral and 220 hot to hot. If you loose the neutral then there is no reference for the 120. Depending on the size/load of the devices in your coach the 220v power is split between the load(s) on phase A and Phase B. What ever amount of current flows thru on must flow thru the other. If you had only two devices powered up (one on each phase) and they were of equal resistance than the voltage would be split equally. BUT, if one has more resistance than the other then the voltage will be split proportionally. This is (I hope) just a simple explanation. There are more factors but basically, this is how it works.

ddtuttle

aka Billy Byte (trusty hound)
2000 Allure #30443

Re: intermittent electrical problems

Reply #16 –
Yahoo Message Number: 55791
Quote
Basically, the neutral is the reference wire for the voltage lines. You >have two hot wires which are 120v to neutral and 220 hot to hot. If you >loose the neutral then there is no reference for the 120. Depending on the >size/load of the devices in your coach the >220v power is split between the >load(s) on phase A and Phase B. What ever amount of current flows thru on >must flow thru the other. If you had only two devices powered up (one on >each phase) and they were of equal resistance than the voltage would be > >split equally. BUT, if one has more resistance than the other then the >voltage will be split proportionally. This is (I hope) just a simple >explanation. There are more factors but basically, this is how it works.
Very good explanation and I already understood this relatively simple voltage divider

circuit. Now you need to explain this to others on this group who don't. Of course the

fact that they don't understand it doesn't make it any less true.;=)) The bottom line is that an open or weak neutral can be a disaster in your coach or home.

Unfortunately, there are countless real life examples of this happening.
Since the EMS system uses mechanical relays, I seriously doubt that it can disconnect

power fast enough to prevent damage. This is why many folks test each leg of a 50amp

plug with a heavy load *before* connecting to it. If it cannot maintain correct voltage,

the neutral may be weak and open up later under load......*after* EMS has allowed

a connection.:-(((
TF

Re: intermittent electrical problems

Reply #17 –
Yahoo Message Number: 55792
Maybe this makes it easier to understand

l__l__l

120 NEUTRAL 120

l 120 l 120 l With Neutral

l___l

120 120 No Neutral

Mikee

Re: intermittent electrical problems

Reply #18 –
Yahoo Message Number: 55793
There's another way to look at this. Lets say you have an air conditioner motor on one leg and it draws 3 amps and on the other leg you have a TV and your stereo that draw .3 amps when turned off due to the logic circuits. The motor requires as much as 5 times current to start rotating, if the neutral is dropped then the motor is going to draw 15 + amps, times 2+, through the circuits of the TV as it has no transformer and through the transformers of the stereo equipment, the fusses aren't going to blow fast enough and pow! TV's, Microwaves, inverters, anything plugged in are in danger. Remember current is what kills. Plus when you start talking 30 amps being pushed by 220, the wiring in the coach is rated for 1/2 that is in danger, and connectors and wiring on our appliances are rated for far less. If that isn't bad enough, now all the grounds and chassis of appliances are now hot and if we should be unfortunate to touch metal, well that would be sad.
TWI 2004 Intrigue 11731

Original Message:
-----------------

From: mbaul Mbaul@... Date: Tue, 19 Jan 2010 10:05:56 -0500 To: Country-Coach-Owners@yahoogroups.com Subject: Re: [Country-Coach-Owners] Re: intermittent electrical problems

Maybe this makes it easier to understand

l__l__l

120 NEUTRAL 120

l 120 l 120 l With Neutral

l___l

120 120 No Neutral

Mikee

In a message dated 01/19/10 09:35:44 Eastern Standard Time, william_byte@... writes:
TF Basically, the neutral is the reference wire for the voltage lines. You have two hot wires which are 120v to neutral and 220 hot to hot. If you loose the neutral then there is no reference for the 120. Depending on the size/load of the devices in your coach the 220v power is split between the load(s) on phase A and Phase B. What ever amount of current flows thru on must flow thru the other. If you had only two devices powered up (one on each phase) and they were of equal resistance than the voltage would be split equally. BUT, if one has more resistance than the other then the voltage will be split proportionally. This is (I hope) just a simple explanation. There are more factors but basically, this is how it works.

ddtuttle

aka Billy Byte (trusty hound)
2000 Allure #30443

mail2web.com - Microsoft® Exchange solutions from a leading provider - http://link.mail2web.com/Business/Exchange

Re: intermittent electrical problems

Reply #19 –
Yahoo Message Number: 55795
Don,

An open neutral will probably not expose the appliances to 220V, but it certainly could be more than 110V. Explanation below:
Without a connected neutral you would have a floating neutral in the coach. In normal conditions, appliances on the A Leg and the B Leg are connected to this common, connected neutral and receive 110V. Without the neutral connected to the power company, the A Leg appliances are effectively and collectively connected in series to the appliances on the B Leg. If the total resistance of all appliances that are turned on, on the A Leg equal the total resistance of the B Leg, then you are lucky and will evenly divide the 220 V between the two legs, or 110V each. In the extreme case when, let's say, the B Leg is shorted to the floating neutral, then the voltage on the A Leg would be 220V. But lets say the resistance of the ON appliance on the A Leg is twice that of the B Leg, then the voltage on one leg will be (1/3)*220V or 73V and the other leg will be (2/3)*220 or 147V -- not a good condition.
BTW, if all of the loads (appliances) on one of the legs were OFF, then the you will find that all the appliances on the other leg would be OFF (because the floating neutral is basically disconnected from any power.

Herb

2007 Allure #31466 (SOLD)

Re: intermittent electrical problems

Reply #20 –
Yahoo Message Number: 55796
I've gotta step in here because after carrying an electrical Masters' license for 43 years, I'm getting confused with all of the explanations. I'm not sure where to start, but briefly, there is no way (in a single phase 4 wire residential system) for any 120 volt consuming device to get 240 volts to it when the neutral is lost. When the neutral is lost on a 120 volt circuit, there is no return path for the current. The circuit is , at that point, an open circuit and NO current will flow. There are some exceptions to that, but generally, that's what happens. In a 120 volt circuit the amperage is the same on both the hot wire and the neutral (return) wire. On a 240 volt circuit if there is 10 amps on one leg and 13 amps on the other leg, for example, 3 amps (the difference) will flow in the neutral wire. If the amperage in each of the hot legs is equal, NO current will flow in the neutral.
In the scenario that was originally cited, if the neutral dropped, I can't see any way that that there could be any damage to anything in the amount of time it would take for the contactor to open.
As usual there are always exceptions for unusual circumstances.

Dave Trotter
Intrigue 11215

Re: intermittent electrical problems

Reply #22 –
Yahoo Message Number: 55798
Dave, it's easy to demonstrate.....disconnect the neutral supply line from your house and stand back!!!;-)) On second thought, don't do this as one with a "Masters' license for 43 years" might be very embarrased.
TF

I've gotta step in here because after carrying an electrical Masters' license for 43 years, I'm getting confused with all of the explanations. I'm not sure where to start, but briefly, there is no way (in a single phase 4 wire residential system) for any 120 volt consuming device to get 240 volts to it when the neutral is lost. When the neutral is lost on a 120 volt circuit, there is no return path for the current. The circuit is , at that point, an open circuit and NO current will flow. There are some exceptions to that, but generally, that's what happens. In a 120 volt circuit the amperage is the same on both the hot wire and the neutral (return) wire. On a 240 volt circuit if there is 10 amps on one leg and 13 amps on the other leg, for example, 3 amps (the difference) will flow in the neutral wire. If the amperage in each of the hot legs is equal, NO current will flow in the neutral.

In the scenario that was originally cited, if the neutral dropped, I can't see any way that that there could be any damage to anything in the amount of time it would take for the contactor to open.
As usual there are always exceptions for unusual circumstances.

Dave

Intrigue 11215

Quote from: David Tuttle \[br\
]

Re: intermittent electrical problems

Reply #23 –
Yahoo Message Number: 55799
Excellent explaination David. The neutral bus in the campground power post and in the coach main power panel needs to be isolated from the electrical panel it is in. The ground bus will be grounded to those panels. That is where the confusion arises with some folks. The neutral and ground needs to be separated in any surge protection device installed.
There has been some confusion between TF and myself about what we are talking about. I think TF is talking about the relays in the Energy Management System (EMS), and I am talking about the Progressive Industries surge power protection device. Right row but the wrong seat.

Chuck & Mary B

Las Vegas, NV

Shelby Dog, Miss Kitty, Mr Lucky Cat

Re: intermittent electrical problems

Reply #24 –
Yahoo Message Number: 55800
Except the legs are 180 out of phase... So the potential between them is the amount of phase difference.... should be 180.... so when one is at max negative the other will be at max positive..... So it is not going to 0 but an amount exactly opposite of itself... 120 is the RMs of typical service The actual peak is higher... At the "crossing" of the sign waves from positive to negative the difference will be 0, but at max positive on one and max negative on the other is will be the peak to peak voltage of the 2 lines...And yes this is assuming at least one device is on on each leg. Everything being off is quite rare, refers, acs, heat, inverters, lights, alladins, etc etc, .
A lot of technical speak to say it will and does cause an expensive condition that you want to avoid. When someone tries to prove TF wrong please send me the pictures... And have all the camers s ready as it does not last too long.... but it is quite a sight while it is happening...

Mikee