Campground Breakers - EDITED

[2chiefsRus]

We have been traveling in our current motorhome for nearly 12 years, with 8 years of it as full timers and the last four at 3/4's of the year so we are very familiar with this coach. I heard something yesterday from a campground owner that I doubt. The campground's electrician said that the campground breakers on the pedestal do not get weak over time and should not need to be replaced.
Here's the situation - pulled in to the campground, plugged into 50 amp, Progressive Industries hardwired unit showed good power, fired up both air conditioners and after about 1 hour, the campground breaker tripped. PI showed no errors.
We shut down both AC's, reset the pedestal breaker, and started up one AC only for about 2 hours. By that time it was cool enough that we didn't need AC for the night.
Two days later, we fired up one AC and then the second AC about 15 minutes later, and the pedestal breaker tripped again after 45 minutes of both AC's running. Reported problem to Campground, said they would look into it.
Next day, exactly same situation when we turned on both AC's, one first and then the second one 15 minutes later. From what I have read on this forum, it sounded like a weak breaker that needed to be replaced. That is when we were told that breakers don't get weak and need to be replaced.
What do you think? Could this be a problem with something going wrong in our coach as the campground is implying? We will be moving campgrounds in a couple days and want to know what to be watching.

EDITED TO ADD - Moved to another campground and both AC's ran for over 4 hours without any problem at all. So I guess the electrician at the last campground has some work to do.

[Bruce_Brown]

2chiefsRus wrote:
Original poster here - seems like this thread has been taken over with a different issue. Don't think that all the comments apply to the original post.

Agreed - and it seems like the issue is resolved.

[2chiefsRus]

Original poster here - seems like this thread has been taken over with a different issue. Don't think that all the comments apply to the original post.

[CA_Traveler]

ivylog,

Thanks for the update. With a all electric rig they would be candidates for a PI HW50C with inside remote since they have to manage their electric usage.

Kinda wonder about a 50A autoformer also. But in 15 years I've only had low voltage at one CG on 50A but, my rig is not all electric. Of course I anticipate low voltage on 30A.

[Ivylog]

“There is more to this story”...yes, you could hang meat inside and it was a all electric rig. Usually happen when he was taking a shower and she was cooking. Talked him into using the diesel burner if she was making dinner...problem solved.

[CA_Traveler]

Ivylog wrote:
Park changed the 50A breakers and the new tripped too. Two ACs and a Aqua Hot with 2 electric elements will overload most systems.

The mode 600D has 2X 2000W heaters. 16.7A + 15A A/C = 32A.

That leaves 18A on each leg which is certainly manageable. Of course if he has other high draw appliances and uses them all. Or the loads aren't balanced on the 2 hots. :h

He could turn off the A/C heat pumps and use just the Aquahot on electric and diesel. :S If the A/Cs are for cooling then the Aquahot would be for hot water only and the situation is even more managable. We turn on ours for hot water and then turn off. And of course leave it on when used for heating.

There is more to this story...

[2chiefsRus]

Horsedoc wrote:
No advanced degrees here. I got tossed from the third grade because it looked bad to have my son pass me to the fourth. I did spend the night in a Holiday Inn once however. 😉 😉

We stayed the night in a CG in SD with a weak breaker. Progressive unit kept denying power. Owner changed the breaker and said the breaker was weak ( a spring maybe?) Power came right up with the new breaker in place.
That likely adds nothing to the discussion however.

no but it is the information I was looking for 😄

[Horsedoc]

No advanced degrees here. I got tossed from the third grade because it looked bad to have my son pass me to the fourth. I did spend the night in a Holiday Inn once however. 😉 😉

We stayed the night in a CG in SD with a weak breaker. Progressive unit kept denying power. Owner changed the breaker and said the breaker was weak ( a spring maybe?) Power came right up with the new breaker in place.
That likely adds nothing to the discussion however.

[DrewE]

ArchHoagland wrote:
https://en.wikipedia.org/wiki/Electrical_impedance


Impedance is the reason current draw goes up as voltage goes down.

Impedance is the AC equivalent to DC resistance.

A constant impedance would mean that the current goes down as the voltage goes down, rather than up. (And that of course is also true in the DC case with a constant resistance.)

[ArchHoagland]

https://en.wikipedia.org/wiki/Electrical_impedance


Impedance is the reason current draw goes up as voltage goes down.

Impedance is the AC equivalent to DC resistance.

[DrewE]

I am not an electrical engineer, but I am a computer engineer (Master's from RIT) and that involved about 1/3 EE, 1/3 Computer Science, and 1/3 its own classes. Certainly there are many who know more than I do, but I'm not wholly ignorant of what I am saying...or at least attempting to say. It's very possible that what I think, and am attempting to write, is not quite making it into words very clearly.

Power is defined as voltage times current (at any given instant, or an average integrated over time); I have no argument there, and of course the definition of power is not Ohm's law.

Ohm's law relates voltage applied to something to current that flows through it, making the voltage proportional to the current with the resistance being the constant of proportionality. Many materials behave in this way in practical circuits, and so may be modeled as a resistor and analyzed using Ohm's law. This implies that the V/I curve for whatever being described is precisely linear, and passes through the origin. If the current through some device goes up when voltage goes down, then rather clearly Ohm's law does not apply to it, or at the least the resistance (or equivalent resistance) is not constant but is itself varying with the applied voltage in some fashion. For electric motors, the relationship of voltage and current also varies with the mechanical load applied to the motor, the speed the motor is turning at, and maybe some other things.

A Thevenin equivalent circuit is a very handy analysis tool for linear circuits. It doesn't apply to circuits with components that have nonlinear behaviors, such as semiconductors, although often an adequate model may be derived by assuming linear response over some limited operating range.

A silicon diode, for example, is hardly linear in its response, but can be modeled reasonably accurately by a pair of Thevenin equivalent circuits: a quite large impedance when reverse biased (the applied voltage is less than the threshold voltage of about 0.7V), and a small impedance with a voltage source equal to the threshold voltage when it's forward biased.

[FloridaRosebud]

DownTheAvenue wrote:

DrewE wrote:

DownTheAvenue wrote:

DrewE wrote:
(Incidentally, the suggestion that current always goes up when voltage goes down is absolutely incorrect for many loads. Electric motors and motor-driven equipment is a rather complicated case; the current may go up, down, or stay the same, at least within some reasonable range of voltages. If the voltage drops low enough, the current will of necessity go down; otherwise you'd have the air conditioner etc. consuming inifinte current when unplugged with the generator off! For resistance heaters and incandescent lights, the current (and hence power consumed) drops as voltage drops.)

In other words, Ohm's Law is not a fact. WOW! I did not know that. Thanks for posting this new relevation!

Ohm's law is a description of how many, but certainly not all, things behave electrically. Ideal resistors follow Ohm's law; practical physical resistors (including such things as wires and fuses) come very close indeed to the ideal, over a wide range of voltages and currents. Of course, for things that follow Ohm's law, the current is proportional to the applied voltage, and so goes down as the voltage drops.

Things like semiconductors and motors under load and incandescent lights are not ohmic, some very much so, and for them the relation of current to voltage is different and generally more complicated. Ohm's law can still be used in some circumstances as a handy analysis tool, perhaps only under fairly closely defined circumstances. In other words, it's still useful at times to treat such non-ohmic things as their equivalent resistances at some specified operating conditions.

I am not an electrical engineer, are you? However, I have several advanced degrees and did do a little study about what you posted, as well as removing a few cob webs from my brain where I did study the science and physics of electricity obtaining an advanced degree, and I cannot support anything you posted. I would appreciate your citing sources so I can better educate myself. Without any citations, I have to assume you are merely an armchair critic without any qualifications.

I'm in the same boat as you, however I am an electrical engineer, have my PE in 12 states, have been practicing for 39 years, and have dealt with 100's, if not 1000's of induction motors, and his statements are pretty much all wrong. I decided not to post and see if others stepped up, which they have. Ohms law is not a guide or suggestion, just like a speed limit is not a suggestion. In addition, the power of a motor is P=V*I. No resistance there. In addition, every, and I mean every circuit can be broken down into a Thevenin(sp) equivalent, where Ohms law applies. In fact, I have taught a course on motors, and motor design and maintenance a few years back. So I have a bit of experience here...

Al

[wa8yxm]

2chiefsRus wrote:
Original poster - Moved to another campground and both AC's ran for over 4 hours without any problem at all. So I guess the electrician at the last campground has some work to do.

No. .. I'd say the other campground does not even have an electrician but needs one. at least they need a manager who's head is not stuck in his exhaust pipe.

[DownTheAvenue]

DrewE wrote:

DownTheAvenue wrote:

DrewE wrote:
(Incidentally, the suggestion that current always goes up when voltage goes down is absolutely incorrect for many loads. Electric motors and motor-driven equipment is a rather complicated case; the current may go up, down, or stay the same, at least within some reasonable range of voltages. If the voltage drops low enough, the current will of necessity go down; otherwise you'd have the air conditioner etc. consuming inifinte current when unplugged with the generator off! For resistance heaters and incandescent lights, the current (and hence power consumed) drops as voltage drops.)

In other words, Ohm's Law is not a fact. WOW! I did not know that. Thanks for posting this new relevation!

Ohm's law is a description of how many, but certainly not all, things behave electrically. Ideal resistors follow Ohm's law; practical physical resistors (including such things as wires and fuses) come very close indeed to the ideal, over a wide range of voltages and currents. Of course, for things that follow Ohm's law, the current is proportional to the applied voltage, and so goes down as the voltage drops.

Things like semiconductors and motors under load and incandescent lights are not ohmic, some very much so, and for them the relation of current to voltage is different and generally more complicated. Ohm's law can still be used in some circumstances as a handy analysis tool, perhaps only under fairly closely defined circumstances. In other words, it's still useful at times to treat such non-ohmic things as their equivalent resistances at some specified operating conditions.

I am not an electrical engineer, are you? However, I have several advanced degrees and did do a little study about what you posted, as well as removing a few cob webs from my brain where I did study the science and physics of electricity obtaining an advanced degree, and I cannot support anything you posted. I would appreciate your citing sources so I can better educate myself. Without any citations, I have to assume you are merely an armchair critic without any qualifications.

[Ivylog]

Park changed the 50A breakers and the new tripped too. Two ACs and a Aqua Hot with 2 electric elements will overload most systems. His electric bill was $230 while mine was $80.