Shore power and generators

[Sherry Klumpp]

Hi All,

  I'm new to the RVing world, and I am getting mixed information about things to do and not to do.  I bought a 35 ft 2005 Beaver Monterey.  I only have access to a 15 electrical supply where I'm storing it.  The place where I purchased had it plugged into a 30 amp supply.  The latter place told me to turn on the generator if I wanted to run both A/Cs.  I did with no problems.

  A mobile tech told me to disconnect from the 15 amp shore supply before turning on the generator.  Otherwise I would trip a fuse if I didn't disconnect from the shore power.  I did trip a breaker when I left it plugged into the 15 amp shore supply and turned on the generator. 

  Who is right?  Is the difference the amperage of the shore power?

  I think I have a lot to learn  !!

Thanks!!

Sherry

[David T. Richelderfer]

watts = volts * amps  OR  w=v * a

Your generator is probably 7,500 watts and creates a 120 volt electrical current.  Thus, your generator is putting out
 7,500w / 120v = 62.5 amps.  These numbers apply to the generator:  120 volts; 62.5 amps; 7,500 watts.  In addition, your generator puts out power on two legs (two wires) with each leg (each wire) getting half the total amps produced -  62.5 amps / 2 = 31.25 amps on each leg or wire.

The shore power cord is 15 amps at 120 volts.  Therefore, your shore power is 15a * 120v = 1,800 watts.
These numbers apply to the shore power:  120 volts; 15 amps; 1,800 watts.  The shore power comes all on one leg - 15 amps on one wire.

Looking at your generator - It creates 62.5 amps.  Air conditioners usually require from 13 amps to 20 amps; 13 to 15 amps after start up and upwards of 20 amps at startup.  Just like driving a car you have to step on the gas to accelerate, then you can let off the gas to maintain speed or coast.  Thus, your generator can run more than two air conditioners.  The engineering design is such that you have two air conditioners (2 * 15 amps = 30 amps) and still have power to operate other devices in the coach (like the TVs, microwave, water heater, etc.) - 62.5 amps - 30 amps = 32.5 amps extra for other devices.  As noted above, there are two legs each giving 31.25 amps.  Your two air conditioners run from both legs - one runs from one leg and the other runs from the other leg.

Looking at the shore power - It is only 15 amps all on one leg.  Since one air conditioner requires upwards of 20 amps to start up, there is a high probability that starting only one air conditioner will kick out the shore power's breaker.  In addition, there are devices in your coach which use a little power at all times.  For example, the engine's brain (ECM), the inverter/charger, other sensors, etc.

I don't know why the shore power needed to be disconnected prior to starting the generator.  To my knowledge, when the generator gets going and provides power, then the transfer switch will transfer away from the shore power and to the generator power as the power source for the RV.  You didn't indicate which breaker kicked out when you started the generator.

[Sherry Klumpp]

Hi David,

  Thank you so much for your explanation.  All makes sense!! Unfortunately, the electrical panel on the Aladdin isn't functioning, so I can't see power sources on legs 1 or 2.  Also the Aladdin has always displayed "no AC 9 (alternating current)" since I've owned it even when it has shore or generator power. 

  I've been to this facility 3 times:
 
1) plugged in to 15 amp shore power but didn't check surge protector to see if it was actually working.  I left only the refrigerator on as I planned to take it out two days later.  I did not turn off coach power.
2) return the second time.  Facility breaker was tripped.  Was it because I turned on the refrigerator before leaving the first time?   I don't know because I didn't check to be sure the facility shore source was actually working when I first plugged in.  There are 4 plugs, and another motorhome is plugged into one of the other 3 plugs.
The refrigerator stopped working before I returned the second time.  Error code was "no co."  They think it is the circuit board.  When I left the second time, all lights and appliances were off, water pump off, refrigerator off and not working.
3) return the third time.  First thing I did was go into the coach and start the generator.  Main power to coach went down- think it threw the 50 Amp fuse.  The facility breaker was also tripped- but I don't know if that happened before or after turning on the generator.

  I've just moved to this storage location, and I've only been out there 3 times.  The first time I moved in, the second to take it out for the weekend and meet friends, and the third to meet the mobile RV technician to address refrigerator and other issues identified while traveling. 

 Thanks for explaining what is running in the background too (the engine's brain (ECM), the inverter/charger, other sensors, etc.),.  People referred to an AC electrical trickle effect, but I didn't know what was running in the background!!

  When I was at another facility and plugged into 30 amp shore power, I would turn on the generator to run the second A/C, etc with no problems.  Once when I had it out, we turned on the generator while plugged into a 50 amp shore power and tripped a fuse on the generator itself, and the generator went down.  The previous owner talked us through that one.  I don't know why these things are happening. 

  Fortunately, losing either generator power or main coach power isn't a routine occurrence.  But I don't know why they are happening, and they shouldn't be.  Those who haven't worked with Beavers much try their best to troubleshoot, but the explanations aren't always the same.... 

thank you!!

Sherry

[David T. Richelderfer]

A couple things I noted while I read your reply to me.

1. The Transfer Switch determines the source of 120v AC power - either from Shore or from the generator, not both at one time.  If the generator is running, then the Transfer Switch favors it.  Only when the generator is off will the Transfer Switch accept Shore power.  It's an XOR thing if you have programmed computers, an "exclusive OR" - one or the other, but not both at the same time.

2. I think you can run your fridge while on 15a shore power.  But to do this you MUST turn off your electric water heater (AquaHot or HydoHot).  It would be good also to have the AquaHot or HydroHot off so it does not operate the diesel/propane burner too.  There are water pumps in the AquaHot/Hydrohot that operate when it's on, and they use power.  The key is to get almost all power using devices OFF.

3. The battery charging function in the Xantrex should be turned to a low amp usage.  My Xantrex Freedom 3000w inverter/charger can be quickly and easily be programmed to use only 5 amps MAXIMUM for battery charging.  If all the batteries are charged and most everything is turned OFF, then this 5 amp restriction will barely keep them charged up.

4. Leave the Coach Power button (aka Salesman's switch) on at all times.  Mine has been on for five straight years.  As long as all the interior lights are off, then there can't be much to operate... other than the fridge.  To operate, the fridge needs the 12v power that comes through the Coach Power button.  The reason they call it the "Salesman's Switch" is so they can leave the light switches on for showing. When salesman steps into the coach and flips ON the Salesman's Switch, then the whole coach will light up.

5. It's a shame your Aladdin is not working!  Have you tried resetting it.  The reset button on my Aladdin is behind an upper cupboard door over the pilot's seat, over the left shoulder.  You should have one somewhere close to there.

6. Is your storage covered.  If so, then solar panels will be of no use for battery charging... assuming you have solar panels.  My coach has two panels and they will just barely keep the batteries going when parked outside with everything else off.

7. At the time of my "new owner's school" five years ago I also was told way too much to remember.  One thing I remember is the fridge will cool faster on propane versus 120v power.  Rich Marsden, our salesman, worked for Beaver in his younger years so is quite knowledgeable of them.  He said to quickly cool down the fridge overnight, put it on propane.

8. Can I assume your fridge is a Norcold model?  Mine is a Norcold LRIM 1200.  My knowledge is pretty much limited to that model.  If so, has the Recall Device been installed on it?  If not, then get it done.  It costs nothing because it's a recall.  But you need to get a Norcold certified technician for it to be no charge.

9. I would submit that if two motorhomes are plugged into a common 15a or 20a shore power circuit, then there will be problems.  Your coach needs most of that circuit's power, as does the other coach, and having both on a common circuit cannot be good.

[Joel Ashley]

The Aladdin Reset on an '06 Monterey, and perhaps an '05, is in the cabinet directly over the entry door.

Joel

[Stan Simpson]

The Aladdin Reset on an '06 Monterey, and perhaps an '05, is in the cabinet directly over the entry door.

Joel

That's where it is on our '05.

[Joel Ashley]

I neglected to mention there are Aladdin troubleshooting docs in the Forum's Coach Assist section...
Home > Private BAC Members Only > Link to Coach Assist

[Sherry Klumpp]

The Aladdin Reset on an '06 Monterey, and perhaps an '05, is in the cabinet directly over the entry door.

Joel

That's where it is on our '05.

Hi Stan,
  I tried the reset.  Unfortunately it didn't work.  All screens are working with exception of the electric.  But I wonder if that's because of the transfer box.

[Sherry Klumpp]

I neglected to mention there are Aladdin troubleshooting docs in the Forum's Coach Assist section...
Home > Private BAC Members Only > Link to Coach Assist

Thanks!  I'll take a look at that!

[Joel Ashley]

The transfer switch is arguably the heart of your coach and though I'm the last one to go to for expertise on that, it's very possible that's the reason the Aladdin isn't reporting electric.  The original but discontinued transfer switch on yours was probably like ours a Surge Guard 40250 or immediate predecessor, and it has alongside its output port (Lines 1, Line 2, Neutral, and Ground) a port for "Data".  That's where a data cable would plug in that goes to the Aladdin ATS Interface module.  I would guess here that that cable is dangling, tied off, or (cringe  ) cut out of the cord reel bay, and never hooked into the replacement Transfer Switch box because it has no data port... just a guess.  The cable may consist of 2 black, a red, and a white wire to a small white phone cord-like plug.

In case your tech hasn't found them yet, on ours and many others the Aladdin modules are located in a bay immediately forward of the curbside rear wheels, the door to which has swing latches underneath the door edge, hard to see without getting down on hands and knees;  your gray and black tanks are in there. 

The new Surge Guard version, as you may already have discovered is a 40350.  Getting the heart of your rig going again is a big start.

I'm still, like others here, curious about your heating configuration.  A propane furnace would necessitate ductwork installation and perhaps multiple heat exchanger and yards of tube removal, an extra space somewhere in a bay, and like the hot water heater, ports cut through bay doors.  Relying only on the roof AC heat pumps for heat is fine until mountain campground or winter park temps go sub-40.  And they won't keep the water bay(s) from freezing.  Consider also the coach resale value sans a Hydronic system.

Joel

[Sherry Klumpp]

The transfer switch is arguably the heart of your coach and though I'm the last one to go to for expertise on that, it's very possible that's the reason the Aladdin isn't reporting electric.  The original but discontinued transfer switch on yours was probably like ours a Surge Guard 40250 or immediate predecessor.  The new version, as you may already have discovered is a 40350.  Getting the heart of your rig going again is a big start.

I'm still, like others here, curious about your heating configuration.  A propane furnace would necessitate ductwork installation and perhaps multiple heat exchanger and yards of tube removal, an extra space somewhere in a bay, and like the hot water heater, ports cut through bay doors.  Relying only on the roof AC heat pumps for heat is fine until mountain campground or winter park temps go sub-40.  And they won't keep the water bay(s) from freezing.  Consider also the coach resale value sans a Hydronic system.

Joel

Joel,
  While this is all new to me, I think the transfer box may be the source of several of my problems.  I think it's why the Aladdin doesn't recognize any AC input- whether shore or generator.  I think it may explain why power has unexpectedly gone down under different circumstances.  This is from a "novice"- meaning me . but I'm more than willing to learn.  The information all of you are providing is invaluable.  I'm saving it and printing it out for the tech.  She is willing to discuss.
  Question is do I go with the 40350 replacement or another model 41260?  For the 40350 there are two models:a RVC1 or RVC2.  Which would you select?  There are two websites: TRC and Inverter Supply.  My guess is that I should order from TRC.  Would you agree?

  Concerning the hot water heater, I think that is yet to be determined.  I need to call Best PreOwned and find out what the heating system is.  For some reason, I don't have the owner manuals for the hydro-hot while I do for everything else.  The previous owner was meticulous in keeping everything in order and together.  So I didn't realize the the Hydrohot was both hot water and heater until it was brought up in this forum!!  The mobile RV tech plans to replace with Aqua-Hot.  She mentioned climbing into one of the compartments to see what was or wasn't there.  I think she plans to do that tomorrow.  Unfortunately, I have an appointment- but I hope I can get out there while she is there.  At the least, I will make sure she gets this info.  She seems to be on the ball.  So far, other than the coach power switch, she has been in agreement with everything both the forum and she has discussed with me.
 

[Sherry Klumpp]

A couple things I noted while I read your reply to me.


5. It's a shame your Aladdin is not working!  Have you tried resetting it.  The reset button on my Aladdin is behind an upper cupboard door over the pilot's seat, over the left shoulder.  You should have one somewhere close to there.

  The previous owner told me about the reset switch.  It didn't help.  Think it goes back to the transfer box, although not knowing much, that's an uneducated guess .

6. Is your storage covered.  If so, then solar panels will be of no use for battery charging... assuming you have solar panels.  My coach has two panels and they will just barely keep the batteries going when parked outside with everything else off.

I have 2 solar panels, but the unit is under a roof.  So no sun exposure to charge panels.

7. At the time of my "new owner's school" five years ago I also was told way too much to remember.  One thing I remember is the fridge will cool faster on propane versus 120v power.  Rich Marsden, our salesman, worked for Beaver in his younger years so is quite knowledgeable of them.  He said to quickly cool down the fridge overnight, put it on propane.

I'm either recording with my phone or taking notes as people explain things to me, as you are absolutely right, there is a lot to remember!!  Thankfully all of these discussions are in the same location and I can copy, paste and print!

8. Can I assume your fridge is a Norcold model?  Mine is a Norcold LRIM 1200.  My knowledge is pretty much limited to that model.  If so, has the Recall Device been installed on it?  If not, then get it done.  It costs nothing because it's a recall.  But you need to get a Norcold certified technician for it to be no charge.

It is Norcold, but I don't recall the model number.  However, someone with a Norcold looked at the unit as it stopped working, and the recalls had been addressed.  He thought, as does the mobile tech, that it may be the electrical panel.  That's yet to be determined.  It will be submitted under warranty.  She knows to call to get approval.  I've called, and I do have a warranty .

9. I would submit that if two motorhomes are plugged into a common 15a or 20a shore power circuit, then there will be problems.  Your coach needs most of that circuit's power, as does the other coach, and having both on a common circuit cannot be good.

so a 15 amp with 4 places to plug in would share the amps?  It doesn't mean each socket supplies 15 amp of electrical power- correct?  I can google that and find out!!

[Sherry Klumpp]

Stan Simpson,

  I looked you up in the directory and sent a private email.  Thanks so much for the offer.

[Joel Ashley]

As to which 40350, I couldn't say.  The website appears to show only one, so I don't know the difference.  I'd consult with TRC or Beaver Coach parts.

[David T. Richelderfer]

Regarding the wall receptacles in the storage facility (and most residences) - The way to know how many amps are available to a circuit is to check the breaker at the panel box.  In residences typically you will have one circuit per room or pair of rooms.  The kitchen though is a different animal; it will have a stove/oven circuit, and perhaps a pair of 15/20 amp circuits because of all the varied and high energy consuming devices like coffee makers, microwaves, refrigerators, toasters, etc.

I am not an electrician, but I would guess the most amperage allowed on a typical wall receptacle would be 20 amps.  If the circuit has 30 amps, then the plug would look more like a 30 amp RV plug because the wires in the cord need to be seriously larger to carry the higher amperage.  The 50 amp RV plug and cord requires even larger wires.

And yes, if a circuit has a 20 amp breaker, for example, then the sum of power used by all the receptacles on that circuit is limited to 20 amps total.  Of note, a 30 amp RV plug is good for a total amperage draw to the coach of 30 amps total on both legs- 30 amps total is available for all concurrent usage.  The 50 amp RV plug delivers 50 amps to each leg in the RV.  So there are actually 100 amps of power available;  it's just that each leg cannot exceed 50 amps of usage.

In more depth, a 30 amp cord has three wires - a 30 amp hot wire, a ground wire and a neutral wire.  A 50 amp cord has four wires - two 50 amp hot wires, a ground wire and a neutral wire.  Each 50 amp hot wire feeds a leg in your coach.  When you use a pigtail to adapt from the 30 amp plug/receptacle to your coach's 50 amp plug, the single 30 amp hot wire has a crossover built into the pigtail between the two legs so the 30 amp goes to both legs.