| Author | Message | ||
| Robert H. (Ultimarv)
Registered Member Username: Ultimarv Post Number: 13 Registered: 2-2007 Posted From: 83.208.52.10 Rating: N/A |
Another baffling topic from me: On the shore power reel-cover is stamped "120vac/60MHz - 240vac/50MHz". Is this a dual voltage coach? It is a Year 2000 Featherlite Vogue 5000. Further investigation (albeit limited) showed the microwave to be dual voltage, along with the aqua hot. The inverter/charger is a Xantrex Trace 3000, but I have no specifications on it to see if it will accept dual voltage and what its output is. We traded our '92 Concept for this one and are shipping it to Europe really soon. Normally, these things get a stepdown (240/50-to-120/60, well 50 would come through) transformer installed on the other side, but I am wondering if this is some kind of dual voltage (120/240) and dual frequency (60/50) coach. If (fat chance) it is, then anything replaced like the water pump recently that was not dual voltage might have a problem. What is the actual meaning of this stamp? How do things work? I found only a couple of posts by searching, but am still... Baffled! (Message edited by ultimarv on May 13, 2007) | ||
| Nick Badame Refrigeration Co. (Dnick85)
Registered Member Username: Dnick85 Post Number: 110 Registered: 2-2006 Posted From: 75.197.10.152 Rating: N/A |
Hi Robert, "On the shore power reel-cover is stamped "120vac/60MHz - 240vac/50MHz". I would assume that the power cord is able to handle 50 or 60 mhz and the coach is set up for 60 mhz since is was built in the US. Make sure that you check all the appliances and the gen set would have to be adjusted for 50 mhz before you attempt to go to europe with the hopes of operateing correctly. Good Luck Nick- | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 143 Registered: 8-2006 Posted From: 207.231.81.59 Rating: |
Well, I DO have an electrician's license, but I DON'T understand that stamp! First, 50 or 60 cycles per second is expressed as 50 or 60 Hertz. 60 MHz, or 60 Megahertz, is radio frequency, actually VHF TV frequency, no doubt about it. So, something was either mis-labeled, or mis-read. A US 50amp shore power cord is rated 120/240 VOLT, 60Hz, 50 AMP. Could this be what it is stamped? This means that there is 50 Amps of 120 VOLT current available between EACH HOT LEG and the neutral wire, and or 50 AMPS of 240 VOLT current between the hot legs. Now, if you are using 30 amps of 240 V, you only have 20 amps of 120 V left to use on each leg. Make sense? 50 Cycles Per Second, 50 Hz, is also provided at lower voltages, and comes through 60Hz transformers at different voltage than a 50 hz transformer. Most AC motors run at synchronous rpm, so they will run at different speed according to the frequency, and the number of poles in the windings. I THINK 50Hz is provided overseas at 110/220 Volts, (mostly 220) which is still used as US electrical slang, although our power is actually provided at 120/240 V. Bottom line? The cord has to be mis-labeled, as it isn't your TV antenna. Your 60Hz clocks will all run slow on 50Hz, as will all your motors. I have never tried to run a 60Hz air cond compressor on 50Hz, so I can't speak about what might happen overseas. Transformer appliances will probably be ok. If the water pump is AC, it will just run a little slow. When, and if you slow the gen down to 50Hz, the voltage will drop also. This is scary, and I think I would talk to someone who imports/exports on a regular basis, AND has success in doing this! Whew!.......................Sean, where are you? George | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 1894 Registered: 1-2001 Posted From: 75.108.82.12 Rating: |
I agree with George, either you are reading the label incorrectly or you hava e cable reel designed for transmitting television signals. In the majority of overseas areas, the power is 50 hertz at many different voltages. The most common is 220 volts single phase or 380/220 volts three phase. Saudia Arabia and Korea are the only countries I am aware of that supplies 110 volts at 50 hertz. Ac motors will run 20% slower on 50 hertz and their HP will also be diminished by that amount. I have seen 60 hz A/C's operate on 50 hertz, as long as the input voltage is correct, but their performance is significantly degraded. Richard | ||
| Gary Pasternak (Cessna5354)
Registered Member Username: Cessna5354 Post Number: 19 Registered: 2-2007 Posted From: 64.12.116.203 Rating: N/A |
Correctly and well said George & Richard. Also You can imagine as to how "Time will fly" if your clock (60Hz) was plugged into 60 or 50 MHz.. Gary | ||
| Robert H. (Ultimarv)
Registered Member Username: Ultimarv Post Number: 14 Registered: 2-2007 Posted From: 83.208.52.10 Rating: N/A |
Again a big thanks! I mis-read. It actually says "120vac/60", then below is "240vac" and a blank field that has the number "50" stamped inside. I guess the most valid answer is the power rating of the cable. We are just going with the simple stepdown/up auto transformer rated at 10,000 watts. This could be overkill, but safe and easy. But who knows, this coach surprises me all the time and it could be a radio station transmitting from the rear end as we go down the road :-) | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 1895 Registered: 1-2001 Posted From: 75.108.82.12 Rating: N/A |
Glad to hear that. It now makes some sense. The blank field is the Ampere rating. 50 amps at 240 volts. It is in all probability a four conductor, six guage cable with two hots, one neutral and one ground. An auto transformer is really not designed for the application that you are contemplating, but it might work ok. It would seem that a 240 volt to 240/120 volt transformer would give you the 120 volt neutral connection you need. Just be extremely careful in Europe as the voltage between two hots is typically 380 volts, not 240. Remember the line to neutral voltage is 240 volts in 50 hertz countries. Richard (Message edited by DrivingMissLazy on May 14, 2007) | ||
| John Jewett (Jayjay)
Registered Member Username: Jayjay Post Number: 370 Registered: 1-2001 Posted From: 70.244.17.217 Rating: |
Hmmm...120/240 is 25 amps per phase to neutral and 50 amps phase to phase...not as stated above. We must also remember that multi-national commerce demands that products we purchase are viable in multiple markets, and thus are marked accordingly. Oh, and by the way, the National Electrical Code says it's a no-no to install an autotransformer in your bus. Cheers...JJ | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 1898 Registered: 1-2001 Posted From: 75.108.82.12 Rating: |
I have to respectfully disagree with Jayjay. Typical campground 240/120 volt shore power outlets are rated at 50 amps per leg (two legs), for a total of 100 amps (50 amps per leg) at 120 volts for a total of (12,000 watts). These two legs are out of phase 180 degrees and can not be connected in parallel. For 240 volt circuits a total of 50 amps at 240 volts is available. Again for a total of (12,000) watts. Shore cords are also rated for the same amperage and are typically #6 conductors. Richard (Message edited by DrivingMissLazy on May 15, 2007) | ||
| Jim Wilke (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 139 Registered: 2-2001 Posted From: 69.77.157.45 Rating: N/A |
I think you are going to destroy some of your equipment on European power. Much of the consumer electronics today won't even function if the voltage or frequency isn't within about 1%. Anything with a computer (PC board) is in big danger or will not operate. We have seen huge problems on yachts where the electronics must have 60 HZ & they malfunction when the genset drops to 58 or 59 as it reaches full load or goes to 62 as it is unloaded. I'd stay on genset unless I could achieve 120/240 60Hz power. Also remember that the Europeans do not bond the neutral! I would habitually & carefully check for voltage between your bus chassis to earth (or nearby plumbing, electrical boxes etc.) before completing the circuit between the two with someone's body!!! We've seen hazardous voltages here in the US at campgrounds, and what is an annoying zap when it's dry could kill you when you are wet! Their juice is twice ours so the danger is very real. Jim-Bob | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 1899 Registered: 1-2001 Posted From: 75.108.82.12 Rating: N/A |
I think Jim is right on in his warnings. I built a very successful business manufacturing high power inverter/frequency changing/voltage changing devices for the super yacht industry. Power ratings from about 25 kw to several hundred kw. Equipment was specifically designed to permit European 50 hertz boats to plug into 60 hertz power at US marina's and permit US manufactured 60 hertz boats to plug into European frequencies and voltages. Based on my experience with literally hundreds of these installations I would strongly suggest you be very very careful about what you plan to do. Richard | ||
| Robert H. (Ultimarv)
Registered Member Username: Ultimarv Post Number: 15 Registered: 2-2007 Posted From: 83.208.52.10 Rating: N/A |
The whole issue of onboard electronics concerns me, but there are also literally thousands of US coaches, some of them being large rigs such as ours, operating in Europe and converted simply by using transformers. We meet many at the motorsport activities we attend. All of the specialist converters in the UK we have spoken with simply recommend hardwiring a stepdown/up transformer (incorporating initial input protection) of about 5,000 watts to do the job. Most 240/50 connections there only offer up about 16 amps. This solution does not, of course, change the frequency, which was a main area of interest for me, but not a concern for the converters in Europe. A transformer/frequency converter, as found on many super yachts with sensitive electronics, would be ideal if not inherently large and expensive. At least I have not found any that are practical yet. The microwave, aqua hot and air units installed on the coach are to 120/60~220/50 specification, but some items, like the newly upgraded Mach 5 water pump, are purely 120/60. I am the first to admit having little or no electrical engineering experience and have to rely on a combination of information to hopefully get it right. In this regard, I very much appreciate the postings on this unusual topic and offer my sincere thanks for recommendations! (Message edited by ultimarv on May 15, 2007) | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 548 Registered: 1-2003 Posted From: 66.82.9.59 Rating: N/A |
Good comments from everyone. Electronics are probably among the items that are least likely to be impacted by 50Hz (vs. 60Hz) power. That's because most of your electronics are either DC-powered from the batteries to begin with (e.g. GPS units, car-type audio systems), or are equipped with switching power supplies (e.g. computers, LCD TV's, etc.), which don't care about frequency. (Older switching power supplies DO care about voltage, though, and many dual-voltage supplies have a switch for 110-120VAC vs. 220-240VAC. Newer supplies often detect or adjust automatically.) The things that are most likely to cause problems are synchronous motors. Air conditioners, for example, may be built for one frequency or the other, or they may be built to work fine on either (usually through use of a "universal"-type motor, though the output may have to be de-rated on 50Hz). So you will probably be fine with a simple transformer (though, for a variety of reasons, I would use a full isolation-type transformer rather than an auto-transformer), as long as you first carefully check your motors and your high-dollar AC appliances, such as your microwave, TV sets, and household-type stereo systems for the dual-frequency rating. If it's not rated for 50Hz, I'd unplug it to be on the safe side. One other cautionary note: certain hydraulic-type circuit breakers are rated at a particular frequency. Marine breaker panels, for example, are famous for these type of breakers. So if you have this type of circuit breaker, you may need to check the ratings and replace or de-rate as necessary. Household thermal-magnetic breakers are generally not that sensitive, although they may only be rated for 60Hz. If this concerns you, convert your panels to Square-D "QO" series breakers which are rated independent of frequency (and are even rated for DC use). HTH -Sean http://OurOdyssey.US | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 144 Registered: 8-2006 Posted From: 207.231.80.150 Rating: |
Richard, Sean, and Gary, Thanks for the help! I should have included watts, which might have made it clearer. Watts are electrical horsepower, and are derived by multiplying amps times volts. So, 240V times 50A = 12,000 Watts. 120V times 100A (50 + 50) also equals 12,000 Watts. Consequently, any combination of 120/240V current totaling 12K Watts is available. I don't want to jump on the one erraneous poster, but Ohm's law as originally figured out by the Italians is I=E/R. I being Amps, E(Electromotivo, or something like that) being Volts, and R being resistance, or impedance. It is possible that he got the un-balanced current in the neutral confused with something else? The whole purpose of this post is to remind Robert of something we all have missed. The transformer, if used, MUST BE 220V primary, and 240V secondary, CENTER TAPPED!!! a PLAIN 220/240 TRANSFORMER will wreak havoc with all of the line to neutral (120V) loads in your rig, regardless of frequency. If your converter doesn't know what a center tap is, maybe called a middle connection or something, DON'T LET HIM NEAR YOUR RIG! Putting only 240V on the hot legs, and expecting the 120V loads to equalize themselves = smoke. George | ||
| Robert H. (Ultimarv)
Registered Member Username: Ultimarv Post Number: 16 Registered: 2-2007 Posted From: 83.208.52.10 Rating: N/A |
Thanks George. Got that down! We are printing these recommendations to go over with the UK conversion people. I am sure they have done US 50amp coaches before, but we want to make sure all is correctly done. Everybody's been great here! | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 1900 Registered: 1-2001 Posted From: 75.108.82.12 Rating: N/A |
"It would seem that a 240 volt to 240/120 volt transformer would give you the 120 volt neutral connection you need." Good points George. I always appreciate your posts. Your point about the center tapped transformer is what I was referring to in the quote above. I just did not really make it strong enough to be sure Robert would understand what the need was for. Thanks again for clarifying that point. Richard | ||
| Gary Pasternak (Cessna5354)
Registered Member Username: Cessna5354 Post Number: 22 Registered: 2-2007 Posted From: 64.12.116.203 Rating: N/A |
George, You related the age old axiom of electrical equipment. All transformers, circuit boards and equipment will work until you LET THE SMOKE OUT!!! Once the smoke is out the unit will not operate. GP | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 146 Registered: 8-2006 Posted From: 207.231.81.59 Rating: N/A |
Gary, I'm up off the floor now, and should have the rest of my breath back in a minute or two! Or as Kyle said, ROTFLMAO! (The A IS a body part) which shouldn't be posted. Thanks! George |
