Connecting to a Single 15 amp Residential Circuit

I've got a 2012 Holiday Rambler Endeavor 43 DFT that I want to connect to a single 15 amp residential circuit so that I can power the refrigerator and a few LED house lights while parked in front of our home for 12-18 hours prior to our departure.  I've got all the physical connections covered - i.e., the extension cord and necessary dogbones to make the connection from a 50amp plug on the coach - to a standard 3 prong plug that I can connect to an extension cord plugged into a standard 15 amp circuit.    My question is focused on what adjustments should I be making at the control panel (a typical Magnum ME-RC50 panel).  What parameters do I need to "tweak" to set the system to run off the 15 amp shore power source? 

You shouldn't have to make any any adjustments at all Spacenorman. Our Magnum remote auto-senses whatever we're plugged into and adjusts the load-shedding accordingly. We've plugged into a household socket a few times over the years, and just let the system do its thing. You're not going to be able to run two AC units, but it'll run our res-fridge, LED lights and TV just fine.

Kev

I suppose you could set it for 20 amp if you want, but Kev is right, in that you shouldn't need to do anything except not run too much at once. Unless, perhaps, the batteries are so low that you require a huge charging current.

Nothing.

Some people think they need to reduce the charge amps/percentage on the control panel, but that is rarely ever needful.  The main purpose of those parameters is to prevent the charger from hogging too much of the available DC power, which can happen if the batteries are extremely low and accepting a lot of charge amps. Other than that scenario, the inverter/charger won't use more than a couple amps and there will still be plenty left of that 15A for fridge heater.

If all you want to power is the Fridge and the Converter (The thing that charges the battery) no heaters of any kind (Save the fridge) no air conditioners.. You can buy an adapter at most RV'stores that will let you plug in to any standard house outlet.. You can't run much, but it will work.

If you can't find a 50-15 amp adapter. Then go 50-30 and 30-15  Even Wal-Mart can sell you those.

spacenorman said:

I've got all the physical connections covered - i.e., the extension cord and necessary dogbones to make the connection from a 50amp plug on the coach - to a standard 3 prong plug that I can connect to an extension cord plugged into a standard 15 amp circuit.

My question is focused on what adjustments should I be making at the control panel (a typical Magnum ME-RC50 panel).  What parameters do I need to "tweak" to set the system to run off the 15 amp shore power source?

Click to expand...

There is a 10:1 ratio between amps at 12 volts vs. amps at 120 volts, i.e. if you're putting 20 amps into the batteries you're only drawing 2 amps plus a small amount of conversion loss from the 120 volt line.

Like Gary said, you shouldn't have to adjust anything on your charger.

Just remember to shut down your ACs/Heatpump.  I pulled into our old storage lot, plugged in and left, and when I came back the AC was running   Our old units had 2 minute delays and I didn't hang around long enough to hear them start.  I'm surprised the breaker held and I'm surprised the storage owner didn't call and yell at me!

Thanks for the feedback on this one. The reason that I posed this question is that I've had issues powering the coach from this same 15 amp circuit previously - without making any adjustments at the control panel. Previously, when I've connected to the 15 amp circuit at home - power would occasionally drop then cycle back on. It never blew a breaker .. but power would drop in the coach for a few seconds ... then start back up on it's own. If I happened to be outside the coach - I could hear "clicking" which I associated with this issue. I was slow to realize that this was happening ... and left the coach connected to the 15 amp circuit for nearly 24 hours prior to pulling away from home for our trip to Florida last year. As luck would have it - our invertor failed on that trip and have to be replaced. The jury is out as to whether the cycling power contributed to the invertor's failure - or whether the failing invertor was behind the power cycling issue.

I tried connecting to the 15 amp circuit once since the inverter was replaced (again, without making any adjustment to settings at the controller) this past summer. This time I noticed the power cycling problem immediately - so I disconnected from the 15 amp source and simply ran off the generator for the short time I needed to.

I'm about to bring the coach home for a day to load up prior to departing for Arizona. The coach will be there for roughly 24 hours ... where I'm hoping to run the refrigerator, internal LED lights as well provide sufficient power to control the Aquahot while running on diesel. In preparation for this third attempt at powering the coach from the 15 amp source - I went back and read the ME-RC50 controller manual - and spotted reference to this setting. My plan was/is to throttle down the "Shore Power" setting to 15 amp in the hopes that it will solve my issue of repeated power cycling. I figured I'd pose the question on the forum to see what other feedback I'd get.

Thanks all!

I'd be surprised if switching that setting to 15 amps made any difference, but it wouldn't hurt anything to try. As long as you're not pulling a heavy electrical load, you should be getting steady A/C power from 15 amp service. I've never had any trouble at all running small loads when we were plugged into a standard 15-20 amp socket.

Can you tell where that clicking sound is coming from when the power cycles on and off? Could it be coming from the transfer switch? I'm also wondering if your inverter's bypass isn't working properly, but since it seems to work when you're plugged into 30 and 50 amp service, I doubt that's the problem.

Does the power-cycling occur when the inverter is switched on, off or both? You might also want to try a different set of dog bones, just in case the wires in one of them have frayed and are making poor contact.

Kev

How long a run is it from the coach to the outlet? And what are you using for a power cord to reach the outlet. You may be seeing enough voltage drop to trigger the power cut-off.

The reason that I posed this question is that I've had issues powering the coach from this same 15 amp circuit previously - without making any adjustments at the control panel.

Click to expand...

What's on this circuit other than your coach? Most 15 amp outlets in a house have other outlets on the same circuit, so you'll need to check that, too. Sounds as if there's something else on there that is cycling its power usage.

Spacenorman:  Perhaps you could tell us what ME-RC50 parameter you adjusted.  Most people tinker with Shore Max, thinking it somehow limits shore power draw (it does not). That parameter limits how many AC amps the charging function can consume but doesn't otherwise change how much total power the coach can draw from the shore cord. You could still attempt to run the roof a/c, for example, and pop a breaker.

The only power the Magnum can effect is that which flows through it. There are three things power consumption functions in the Magnum:
1. 120v-->12v power conversion (for lights, etc. and i lieu of using battery power)
2. Battery charging
3. 120vac power that flows through to the inverter-supplied circuits/outlets

The Magnum itself receives power from a 30A breaker in the main load center. All the other breakers in that load center represent amp loads that are not and cannot be managed by the Magnum. The a/c units and water heater are examples of that.

The clicking and power cycling you hear most probably is caused by low voltage on the outlet, allowing the auto transfer switch to disengage. Do you have a Surge Guard or Progressive power monitor (surge protector) installed? That would drop power out if there is any sort of problem with the incoming power.

Gary RV_Wizard said:

Spacenorman:  Perhaps you could tell us what ME-RC50 parameter you adjusted.....

Click to expand...

I haven't adjusted anything ... yet.  My first couple of attempts (with no parameter adjustments) is when I experienced the issue with the power cycling.  I've posed this question in anticipation of trying this again on Friday when I'll be parking the coach at home to unwinterize and load up in preparation for a Saturday morning departure for Arizona. 

Based on the comments and suggestions in the responses - I'm going to do a few things different this time.  First, I'm going to change the "Shore Max" parameter to 15 amps.  Second, I'm going to upgrade the extension cord that I'm running from the house to the coach from a cheap orange yard task special ... to a heavier duty contractor extension.  I'm not sure about the specs ... but the contractor extension is certainly a much beefier cable.  I'm also going to take a closer look at what else might be on the circuit that I'm plugging into ... I've been using one located near the door in living room.  As I recall there's not much plugged into it ... but, I think I'll throw the breaker and see what (if anything) else stops working. 

The typical orange outdoor extension is a 16 gauge cord, meaning its max capacity is about 13 amps if in good shape (especially the end connections).  If no more than 25 ft, that's probably OK, if not ideal. A 14 gauge cord is a better choice and readily available at Lowes, Depot, etc. 

Dialing down Shore Max can't hurt, though it is unlikely to make a difference. By itself is has no effect on the shore power draw.

Most 50A powered coaches have a 30A power management (limiting) mode and automatically engage it when the shore power connection offers 120v only. Standard 50A is 240v, so the power management uses voltage to detect 30A or less. Usually there is a pushbutton to adjust the 30A management down to 20A. You should use that if available.  If you have a panel that shows the appliances and an indicator to show power active vs shed for each, that's usually where the button is. Intellitec and Powerline are common brand names.

What else is in the shore power path? Do you have a "surge protector" device of some kind?

Gary - thanks for the suggestions!  I've got an extension cord constructed from 14 gauge cable lined up .. so that should help a little bit. 

Our coach has a power management system as well ... according to the documentation - it's made by Precision Circuits.  There is button there that will step it down to "20 amp service" (which lists everything that is apparently "disabled" when in 20 amp mode).  I'll be certain to turn that down as well.

I do use a SurgeGuard "surge protector as well.  It's one of the relatively inexpensive ($80) devices ... and is shown at the link below. 

http://www.campingworld.com/shopping/item/portable-surge-guard-protectors-50-amp/73995&utm_source=google&utm_medium=cpc&scid=scplp73995&sc_intid=73995&affiliateid=6338&gclid=Cj0KCQiAgZTRBRDmARIsAJvVWAtcq637n0ni6rPyLEc26c2sNwFUhJ1ULw-g7rI1AkIf5Kbk5_eXf4IaAgrSEALw_wcB

When all is said and done - my path to shore power in this instance will consist of 50 amp Coach plug ... into the Surge Guard "Surge Protecter" ... into a 50 amp to 30 amp "dogbone ... into a 30 amp to standard 110V 3 prong plug "dogbone" - into the extension cord. 

From what I'm piecing together out of responses I've received on this and other forums - it's possible that part of the problem the last time I tried this was the fact that my house batteries were in bad shape.  (Last time I tried this was back in early September ... upon our return from that trip I removed and tested each of the 4 UL16HC house batteries and discovered that I had a total of 3 bad cells in the bank of 4 batteries (12 cells total).  I'm thinking that perhaps the charger function may have been kicking in to try and keep my dying batteries charged - and may be the reason that I was seeing intermittent power drops.    All 4 house batteries were replaced 3 weeks ago with new UL16HCLs. 

In terms of power use in the coach - I'm looking to power the refrigerator (a Frigidaire residential unit - which according to the specs draws 8.5 amp @ 120 volts), whatever control voltage used by the Aquahot when running diesel and a handful of house lights.  The house lights run off the DC side of things - and are all LED bulbs ...so I'm guessing the power draw will be minimal.  If necessary - I can power down the refrigerator for the evening.  My bigger concern is keeping the coach interior warm throughout the night before our morning departure.    I'm unwinterizing the coach on Friday afternoon and filling the fresh tank prior to our Saturday AM departure.  The forecast calls for high temps of around 32 degrees ... with overnight lows around 24 degrees on Friday night. 

That surge protector is just that - a protection against power surges. It won't open the circuit on low/high voltage, so that eliminates one possible cause of the power drops.

The Precision Circuits power control only disables (sheds) various 120v devices if they are actively drawing current (amps) and the total of all active devices gets near the 30A or 20A limit (which ever is selected).  If you already had those devices off (a/c, Aquahot electric mode, etc) off, then the PC controller can't do anything more. Still, selecting 20A makes sure that most of them will get disabled if they are accidentally turned on.

Bad batteries will indeed cause the charger to draw more amps in an attempt to charge them up, but we are still talking a modest draw. A charge rate of 60A to the batteries draws about 7 amps from shore power. Half what you have available, though.

The residential fridge draw averages far less than that 8.5A peak. That only happens when it is self-defrosting at the same time the ice maker cycles. Most of the time it will be under 3A, but the peak draw can occur at unpredictable intervals.

None of the above explains how power could drop out and come back, or the clicking noise. That has to be the transfer switch relays kicking out and back in again.

At this point - I'm going to make the changes I mentioned (adjust Shore Max parameter, use a heavier gauge extension cord - and finally confirming that there's nothing else in the house running on the circuit that I'm going to connect to) and see what happens.  If I've got stable power - I'll know relatively quickly.  If I don't - I'll simply have to run the generator and keep an eye on it.  Fortunately, it's cold so nobody's got their windows open such that a running generator will be an annoyance.  I've only got to keep things running like this for 12-18 hours. 

Agree 100%. Do that and give it a shot to see what happens.

Note that drawing too many amps should just trip a breaker in the house. Nothing should be acting strange in the coach.