Voltage

Topic: Voltage (Read 1336 times) previous topic - next topic

Voltage

September 15, 2011, 09:42:05 pm

Plugged in at campground to 50 amps, and line 1 shows 127v while line 2 shows 120v. Line one occasionally spikes to 142v. Going to try the 30 amp service and the 20 amp service to see what happens. Suggestions?

Update: When plugged in to the 30 service, using my 30 amp cord, Line one shows 127v and Line 2 shows 127v

Re: Voltage

Reply #1 – September 15, 2011, 09:51:23 pm

Quote from: aspenpilot – September 15, 2011, 09:42:05 pm

Plugged in at campground to 50 amps, and line 1 shows 127v while line 2 shows 120v. Line one occasionally spikes to 142v. Going to try the 30 amp service and the 20 amp service to see what happens. Suggestions?

I would ask them to move you to a different site and have their maintenance guy repair the electrical service on the original one for the next camper. That way, if it's more than a simple fix, you have a site that's got reasonable power.

Even better if you happen to have a multimeter and can show them it's the site power and not something within your coach.

Michelle

Re: Voltage

Reply #2 – September 15, 2011, 10:07:09 pm

Brian,
I agree with Michelle, I would unplug from that pedestal before a power surge damages your coach. Do you have a surge protector?

Re: Voltage

Reply #3 – September 15, 2011, 10:20:18 pm

I do have a whole coach surge protector installed. Unfortunately, the office is closed until tomorrow. First thing in the morning I'll have them repair or move me. I just check the power outlet at my site as well as the one next to me, and they both showed 240v...120v per side.

Re: Voltage

Reply #4 – September 15, 2011, 10:22:53 pm

When you plug into a 30 amp, both lines will read the 120 volt info, they are reading the same line, this is normal or should I say that is how my coach works.

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Reply #5 – September 15, 2011, 10:28:02 pm

Hey dave,

That's what my coach normally shows as well. This is the first time I ever had any issues.

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Reply #6 – September 15, 2011, 10:36:22 pm

I know in our '03, the over/under protection relay will trip if the voltage goes over (roughtly) 132V. So our coach plugged into that campsite would have the relay clicking all night long. It's not something many surge protectors would protect against if the overage lasts less than 5-8 seconds due to their sampling/response rate.

We were in a campground overnight where we had that problem (Cave Country in KY) and we unplugged.

Is it cool enough where you are to unplug and run off the inverter overnight for any 120V items (i.e. you don't need to run air conditioning)? I wouldn't feel comfortable leaving our coach plugged in under those circumstances, especially not having the over/under protection (I believe it was first used in the '03 coaches).

Michelle

Re: Voltage

Reply #7 – September 15, 2011, 10:36:57 pm

Don't think 241VAC is that far out of line :-) depending how it was measured. If you go hot to hot with the meter probes, you should see double approx 120V if there is 220 at the post. Could be the post is incorrectly wired. How about a word from the electricity expert? Dave?

Re: Voltage

Reply #8 – September 15, 2011, 10:44:02 pm

Pierce,

I measured each side to ground and the independently showed 120v. Measuring hot and hot showed 240v.

Re: Voltage

Reply #9 – September 15, 2011, 10:45:01 pm

Quote from: Pierce & Gaylie Stewart – September 15, 2011, 10:36:57 pm

Don't think 241VAC is that far out of line :-) depending how it was measured. If you go hot to hot with the meter probes, you should see double approx 120V if there is 220 at the post.

I'm not Dave (and I didn't stay at a Holiday Inn Express last night

), but here's a good site that explains how to check the campground's 50A outlet

RV Electric

Click on "Outlet Testing". The 2 outer vertical blades are hot, should measure around 240V between them. The U-shaped one is "ground", and the vertical opposite it is neutral. Should be 0V between ground and neutral, 120V between either hot and one of these.

The tricky thing is going to be capturing that overvoltage spike. If your meter has peak capability and you're patient you might be able to get it. Really more to prove to the campground that they have a problem and should move you.

Michelle

Re: Voltage

Reply #10 – September 15, 2011, 10:47:24 pm

I'm noe Dave either! With that being the case, I'm going to unplug and run off the inverter. BTW, I've ben watching the panel in the coach for the past 30 minutes, and Line 1 has stayed on 127v while Line 2 has stayed on 120v. Thanks to all that helped!

Re: Voltage

Reply #11 – September 15, 2011, 10:49:56 pm

Quote from: aspenpilot – September 15, 2011, 10:20:18 pm

Unfortunately, the office is closed until tomorrow. First thing in the morning I'll have them repair or move me. I just check the power outlet at my site as well as the one next to me, and they both showed 240v...120v per side.

You know what? If the campground isn't that full and you can check any "late arrivals" board for reserved sites, I'd just move to a site that seems to be OK (with your meter) and go in and explain first thing in the morning. Especially if after you plug in everything looks fine in your coach for a while - it will let you sleep easier.

You can always move back if they need you to after they fix the site, and if you explain that you checked first to see if they had any late arrivals coming into the "replacement" site, they shouldn't give you any flack.

Michelle

Re: Voltage

Reply #12 – September 15, 2011, 10:52:41 pm

Michelle,

You must have stayed somewhere good last night ( and probably just as well you are not Dave :-). Nice site. Why didn't I say something like that? A good web site is worth a thousand forum words.

As they say on ebay: ++++++++

Re: Voltage

Reply #13 – September 15, 2011, 10:59:07 pm

Good suggestion, Steve. But..it's dark..I'm hooked up with all of my other amenities..my tire protectors are on..and I want a cold one!

I'll sleep fine unplugged. I checked the spot next to me, and the voltages read the same as at my site. I'll check to see if the voltage between the neutral and ground reads zero.

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Reply #14 – September 15, 2011, 11:02:12 pm

Quote from: Pierce & Gaylie Stewart – September 15, 2011, 10:52:41 pm

Michelle,

You must have stayed somewhere good last night ( and probably just as well you are not Dave :-). Nice site. Why didn't I say something like that? A good web site is worth a thousand forum words.

As they say on ebay: ++++++++

Thanks. I stayed in our FT last night.

(the campground is across the street from a Holiday Inn Express... hmmm.....)

-M

Re: Voltage

Reply #15 – September 16, 2011, 12:16:03 am

Got lucky and saw a maintenance worker outside. I showed him what was happening, and he's calling his electrician in the morning. When I measured left hot to neutral the volts read 120v, but when I measured between left hot and ground the reading was 124v. The right hot and neutral measured 120v, but the right hot and ground measured 117v. Between neutral and ground the reading was 1v. I'm not an electrician by any stretch, but these reading don't look correct. Just to make sure, I did the same at the site next to me and had the exact same readings. The maintenance worker said that the two power receptacles come off the same bus and are wired the same.

Re: Voltage

Reply #16 – September 16, 2011, 09:38:50 am

If you are reading across the two spade connections at the panel you should be 240-245V. That tells you you are getting both phases. One spade to upper/lower (ground/neutral) - 120-130V

Re: Voltage

Reply #17 – September 16, 2011, 10:57:02 am

What is a practical example of what would cause this condition?

Re: Voltage

Reply #18 – September 16, 2011, 11:13:53 am

Quote from: Gayland Baasch – September 16, 2011, 10:57:02 am

What is a practical example of what would cause this condition?

I'm going to hazard a guess at a couple of things.

1) Improperly sized or high impedence neutral wire.

2) Voltage on campground "ground". Voltage is a differential reading. If the ground has a (phantom or real) potential the differential at the hookup might read 120V, but the one in the coach can read high if it's using a different ground reference. We had this once, opted to unplug for safety. Part of the cause was poor ground connections (high impedence/loose) in the campground

3) Something plugged into the same bus that is miswired; often "ground" and neutral tied together (big no-no). Return current from the neutral polluting the "ground", causing #2 above. A miswired RV (we believe) was the other part of the issue we experienced that I mention in item #2. Our issue was coincident with a clearly home-modified unit arriving in the campground and went away when they departed. We did find campground "ground" issues while debugging and fixing them helped somewhat, but didn't completely eliminate the problem.

I expect the more expert minds here will think of other scenarios.

Michelle

Re: Voltage

Reply #19 – September 16, 2011, 11:21:16 am

The 147 volt reading is way-way out of standard and dangerous to all concerned (electric equipment), the normal voltage range is 120/240 volt target, with that you have the UL acceptance range of +/- 10 %. Now looking at the 120 line, with the +/- 10% your range is 108 - 132 volt. I do not like either end of that range, but UL claims it is OK.
Same goes for the 240 volt reading. I am not too concerned at the 240 volt reading because I only use the 120 volt readings.

One could write a long long study on this subject starting when normal was 110/220 volt. Now normal is running closer to 125/250 volt. You can keep an eye on your monitor to keep your self happy and when things start going nuts, unhook from the power post.

For me, I am happy when the range is between 114 - 128 volt, that is on each leg, if your into the 240 reading, that would be 228 - 256 volt.

Same goes for the generator with the additional UL standard of +/- 5% for frequency, think 57 to 63 hertz/cycles, 60 is the target.

As usual FWIW.

Re: Voltage

Reply #20 – September 16, 2011, 12:14:34 pm

For those interested, The generator overall has been more stable on voltage than the power company for 1 good reason, (I am referring to the Power Tech Gensets), while the generator is capable of 120/240 volt, Mine is connected for only 120 volt operation, this puts all 10 kw on the 120 volt line. Generators are regulated by the 120 volt sensing. If you were to have the 120/240 volt setup, still have the 120 volt sensing, as you load down one side of the generator, depending on which side, the voltage might stay very dependable because the regulator is on that leg, but if the regulator is on the other leg, your loaded side might drop way down, how far depends on how much load. This would also give you some crazy 240 volt readings. This is exactly why the 120 volt only generator is far better than having the dual voltage, also with the dual voltage, and say a 10 kw, on 240 volt you only have 5 kw per leg., So keep load balanced.

For the die hards, do you know if your power post is giving you true power or appearant power ? The generator is giving you closer to true power. Think power factor

Not a biggie, but depending on how well the power company is keeping tabs on their loads.
FWIW

Re: Voltage

Reply #21 – September 16, 2011, 12:22:39 pm

Moved to a different spot this morning in a different row. Check the voltage before I moved; everything was fine. Coach is now plugged in and showing 122 on each line.

The electrician is here checking my original spot. I'll report his findings as soon as he informs me.

Re: Voltage

Reply #22 – September 16, 2011, 12:29:45 pm

Dave,

I did read that the 10Kw PT is capable of 120/240 operation. We live out in the country and lose power several times a year. I have connected to the 120 and powered up the house but our well is 240V. How much trouble is it to attach a box with 240 out to the PT? Downside?

And, yes I do make sure the mains are switched off before I power up the generator. Was thinking of an automatic changeover also.

Re: Voltage

Reply #23 – September 16, 2011, 01:06:33 pm

Pierce,
I have not looked at the Power Tech wiring to see how they have it configured, but with the two breakers on the panel, it should not be too hard to swap on to get the 240 output.
If I can find the wiring diagram for the Power Tech as installed in my coach It should be fairly simple to swap the one winding to get it out of phase to get the 240 output. Will take a look see.
Dave M

Re: Voltage

Reply #24 – September 16, 2011, 02:30:53 pm

Quote from: Pierce & Gaylie Stewart – September 16, 2011, 12:29:45 pm

Dave,

I did read that the 10Kw PT is capable of 120/240 operation. We live out in the country and lose power several times a year. I have connected to the 120 and powered up the house but our well is 240V. How much trouble is it to attach a box with 240 out to the PT? Downside?

And, yes I do make sure the mains are switched off before I power up the generator. Was thinking of an automatic changeover also.

Here is a diagram showing what is needed to revert to 240 vac.
Remove Jumper and reverse these 2 wires.

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