A Thank You to the members about low voltage

DrewE wrote:


Basically correct, but it's inaccurate to call it a 100A service. It is a 50A 120V/240V split phase service. None of the wires or connections ever have 100A flowing, and you don't need wire sized to carry 100A, and you cannot power a single 100A 120V device should you happen to have such a beast. You can use up to 50A at 240V, or have two legs of 50A at 120V, but not a single leg at 100A.

Similarly, a semi tractor pulling dual 28' trailers is not a truck with a 56' trailer. The two are far from equivalent if you have some 35' long pipes to haul.

I have argued this same point til I am blue in the face here in the past. LOL

BTW, I am in complete agreement with you. Some folks will never quite get it, though. Loved your analogy - good job!

last year I got a hard wired surge/voltage condition unit on clearance. Installed it and have not once had it trip. This year though I found it works very well. I have my trailer out in front of the barn and plugged in. I was in there cleaning the other day and the AC kept going off, power too, went and checked the breakers, and they were OK, came back and sure enough heard the thunk of the relay and power came back on. It did this a few times, so shut the AC off and power stayed on the rest of the day. I checked my extension cord and sure enough one of the plugs has rust in it, same cords I used the past two years without issues, but I guess now I need a new cord. That unit is well worth the cost, protects not only the RV but whatever it is connected to.

SoundGuy wrote:
It's handy also to be able to monitor incoming source voltage throughout your stay, just as I do with this Kill-a-Watt meter plugged into a galley receptacle.

Bipeflier wrote:
I invested in a Kill-a-Watt a few years ago. Second summer while camping I noticed a higher than normal voltage reading. Pulled out the trusty Fluke meter and voltage on the same outlet read normal.

I called the company and was told that "something has changed" inside the unit. Might read high or low. Well - - Duh! " No repair available, you just need to buy a new one."

Nope, Progressive Dynamics EMS for me now!

If you had bothered to read this thread in it's entirety you'd know I do run a Progressive EMS - the Kill-a-Watt is a convenience and once I calibrated the EMS it matches the Kill-a-Watt readings nicely.

CavemanCharlie wrote:

My only concern with the newer Gray Metal buried units is that the cheap metal is going to be rusted out in a few years. The old post style , though not up to today's code and can not handle today's loads, were around for decades.

In just a few years the buried metal ones are going to be junk and need to replace the metal boxes. Though the wires will still be good.

That's what I think too. I doubt these have much of a corrosion protection coating and if there is, it's probably pretty thin. Hard to understand why the code allows them to be direct buried. At least with wood posts, you can just remove the remains of the old one and drop in a new one without having to re & re any wire connections.

SoundGuy wrote:
It's handy also to be able to monitor incoming source voltage throughout your stay, just as I do with this Kill-a-Watt meter plugged into a galley receptacle.

I invested in a Kill-a-Watt a few years ago. Second summer while camping I noticed a higher than normal voltage reading. Pulled out the trusty Fluke meter and voltage on the same outlet read normal.

I called the company and was told that "something has changed" inside the unit. Might read high or low. Well - - Duh! " No repair available, you just need to buy a new one."

Nope, Progressive Dynamics EMS for me now!

myredracer wrote:

pianotuna wrote:
Hi,

I use a hair dryer to check voltage under load.

Would you care to elaborate about how campgrounds used to be wired vs how it is now?

myredracer wrote:
Checking a pedestal's voltage before plugging in or even backing into a site is not a bad idea but realize that you're testing open circuit voltage and it could drop out of sight with a load on it. Low voltage is common, esp. during the summer heat and in older CGs (due to how they used to wire them).

Nowadays they use those gray metal, direct burial enclosures like in the 1st photo. They have 125 or 200 amp feed-through lugs and by NEC demand rules, can have up to 6 or 7 pedestals (going by memory here on a run of 200 amp wire/cable back to the distribution transformer. Because of "diversity" (not all loads operating a full or high demand loads at the same time), the voltage drop at any one pedestal can be significantly reduced. If you happened to be the only site on a run of loop-fed pedestals, you could have a 30 or 50 amp RV fed by 200 amp wire. These loop-fed pedestals are more efficient electrically and cost less overall to install.

In the olden days, they still had distribution transformers (those pad-mounted boxes you'll see around a CG) but they had panels (100 or 200 amps) mounted on posts distributed around a CG and individual 30 amp or 50 amp runs to pedestals. "Pedestals" were a 30 or 50 amp recept. (and a 20 amp GFCI) and breakers in an enclosure similar to the 2nd photo mounted on a wood post. Sometimes there can be 2 or 3 of these pedestals combined on a run of heavier gauge wire which can serve 2 side-side sites or be some distance away from each other. I've seen some of these older pedestals with a single 30 amp run of #10 quite a distance from the panels. These older pedestals are wired in a "star" configuration in comparison with today's loop-fed design. There's also a lot of variation in exactly how they were wired.

An issue with older CGs is all the 50 amp RVs that are being sold these days. The 50 amp RVs use an adapter but can easily draw loads up to 30 amps, whereas most 30 amp RV owners are used to conserving power and maybe draw 15-20 amps at most on average. The 2017 edition of the NEC has substantially increased the demand load requirement for 50 amp RVs too.

Prior to 2005, the NEC only required 5% of CGs to have 50 amp pedestals (unless they voluntarily built above code min.). So in older CGs you can have a LOT of 50 amp RVs running off 50-30 amp adapters and drawing significantly more power than the original code demand allowance which will also exacerbate voltage problems.

If you pull into an older CG and have a choice of sites, it can sometimes help to pick one closest to a transformer or panel instead of ending up at the farthest end of a run.

Worst CG wiring I've seen was at a CG in Oregon where they had individual #10 romex runs strung overhead between the trees and then an outlet dangling below. Def. not good voltage and def. not to code.

Hope this explains it well enough. A drawing might be better if I had one. If you've ever seen a guy opening panels in a CG and taking photos and notes, that was probably me... :)

My only concern with the newer Gray Metal buried units is that the cheap metal is going to be rusted out in a few years. The old post style , though not up to today's code and can not handle today's loads, were around for decades.

In just a few years the buried metal ones are going to be junk and need to replace the metal boxes. Though the wires will still be good.

I just carry around my Fluke and screw driver and tighten all the loose neutrals in the world. Most receptacles in campgrounds have been abused beyond recognition at the contacts. Burned, overheated, oxidized, bent prongs, etc. I check there first. Keep your plug contacts clean and run your plug in and out a few times to make a better contact when the power is on. A lot of times it's a problem right at your particular pole. If it's at your pole AND the rest of the system, it can make for an aggravating stay.

pianotuna wrote:
Hi,

I use a hair dryer to check voltage under load.

Would you care to elaborate about how campgrounds used to be wired vs how it is now?

myredracer wrote:
Checking a pedestal's voltage before plugging in or even backing into a site is not a bad idea but realize that you're testing open circuit voltage and it could drop out of sight with a load on it. Low voltage is common, esp. during the summer heat and in older CGs (due to how they used to wire them).

Nowadays they use those gray metal, direct burial enclosures like in the 1st photo. They have 125 or 200 amp feed-through lugs and by NEC demand rules, can have up to 6 or 7 pedestals (going by memory here on a run of 200 amp wire/cable back to the distribution transformer. Because of "diversity" (not all loads operating a full or high demand loads at the same time), the voltage drop at any one pedestal can be significantly reduced. If you happened to be the only site on a run of loop-fed pedestals, you could have a 30 or 50 amp RV fed by 200 amp wire. These loop-fed pedestals are more efficient electrically and cost less overall to install.

In the olden days, they still had distribution transformers (those pad-mounted boxes you'll see around a CG) but they had panels (100 or 200 amps) mounted on posts distributed around a CG and individual 30 amp or 50 amp runs to pedestals. "Pedestals" were a 30 or 50 amp recept. (and a 20 amp GFCI) and breakers in an enclosure similar to the 2nd photo mounted on a wood post. Sometimes there can be 2 or 3 of these pedestals combined on a run of heavier gauge wire which can serve 2 side-side sites or be some distance away from each other. I've seen some of these older pedestals with a single 30 amp run of #10 quite a distance from the panels. These older pedestals are wired in a "star" configuration in comparison with today's loop-fed design. There's also a lot of variation in exactly how they were wired.

An issue with older CGs is all the 50 amp RVs that are being sold these days. The 50 amp RVs use an adapter but can easily draw loads up to 30 amps, whereas most 30 amp RV owners are used to conserving power and maybe draw 15-20 amps at most on average. The 2017 edition of the NEC has substantially increased the demand load requirement for 50 amp RVs too.

Prior to 2005, the NEC only required 5% of CGs to have 50 amp pedestals (unless they voluntarily built above code min.). So in older CGs you can have a LOT of 50 amp RVs running off 50-30 amp adapters and drawing significantly more power than the original code demand allowance which will also exacerbate voltage problems.

If you pull into an older CG and have a choice of sites, it can sometimes help to pick one closest to a transformer or panel instead of ending up at the farthest end of a run.

Worst CG wiring I've seen was at a CG in Oregon where they had individual #10 romex runs strung overhead between the trees and then an outlet dangling below. Def. not good voltage and def. not to code.

Hope this explains it well enough. A drawing might be better if I had one. If you've ever seen a guy opening panels in a CG and taking photos and notes, that was probably me... :)

Hi,

I use a hair dryer to check voltage under load.

Would you care to elaborate about how campgrounds used to be wired vs how it is now?

myredracer wrote:
Checking a pedestal's voltage before plugging in or even backing into a site is not a bad idea but realize that you're testing open circuit voltage and it could drop out of sight with a load on it. Low voltage is common, esp. during the summer heat and in older CGs (due to how they used to wire them).

Checking a pedestal's voltage before plugging in or even backing into a site is not a bad idea but realize that you're testing open circuit voltage and it could drop out of sight with a load on it. Low voltage is common, esp. during the summer heat and in older CGs (due to how they used to wire them).

If you travel around to unfamiliar CGs, an EMS is a highly valuable tool to protect your AC unit and other components automatically against low voltage as well as other potential issues like open ground, open neutral, reverse polarity, etc.

A permanently mounted voltmeter inside is also a very good thing to have. Not only for when you first hook up, but to monitor it during the day. Voltage can look good when you arrive, but go up & down over 24 hours like a yo-yo in some cases. If you had an autoformer, you might decide you should hook it up at some point. I installed an LED voltmeter and also an ammeter at the entry door and find them very useful.

Low voltage could also be an indication of a bad connection at the pedestal that should be checked. If you can't move to another site, you might need to keep loads to an absolute min. to reduce chances of a meltdown.

When voltage gets low, the performance of resistive appliances like toasters, coffee makers, etc. and even the fridge can suffer and you can lose 25% of their rating at 105 volts. If your fridge doesn't seem to be cooling enough, it could simply be the voltage.

Worst voltage I've seen was 106 volts before turning anything on. Just the current draw from the converter/charger was enough to push the voltage below 104 volts and the EMS shut us down. Tried 2 more pedestals and same thing. Moved to a section with new electrical and 50 amps and had rock solid 120 volts. The EMS also detected an open ground. Cr*p wiring at that CG for sure!