How to limit current on EHU to stop tripping site fuse?

68c

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Oct 22, 2019
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MH
2001 Pilote 270
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Since 2004
My van is twenty years old so pretty outdated electric system. I am concerned I may trip the site EHU supply by using too much current. Is there a modern device I can fit that will prevent me overloading the trip should I forget and turn on too many 240v things. I suppose it would have to be adjustable to suit the varying site supplies, 6A 10A 16A etc.
 
have you thought of a plug in rcd device into the camp supply and then your van lead out of that?
 
I don't know if you already have an inverter but you could have your existing battery charger replaced with a Combi inverter charger, with this you can then set the level of supply from the hook up and the inverter will match the phase and add any extra power required, not the cheapest solution of course.

Martin
 
Just be aware of your consumption, measure with a meter your base level of consumption without any extra devices, you then know what is left and then just make a note of the current for each device and be mindful ?
 
My van is twenty years old so pretty outdated electric system. I am concerned I may trip the site EHU supply by using too much current. Is there a modern device I can fit that will prevent me overloading the trip should I forget and turn on too many 240v things. I suppose it would have to be adjustable to suit the varying site supplies, 6A 10A 16A etc.

Apart from changing to LED lights most everything in your MH will take more or less the same amount of current as a modern device. IE a 20 year old hot plate or oven rated at 2Kw will take the same current as a brand new hot plate rated at 2Kw.

Don't sweat about it, even the most modern of MHs will trip the site MCB if the owners plug in too much stuff.

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You can buy plug in current monitors, but you'd either have to get a weatherproof one which would have to be outside on your hook-up cable and hence you'd have to keep going outside to read it. Or you'd have to alter the internal 240v wiring to insert it into the wiring as the 240v enters the MH.

Don't worry about it !!!

You could get a cabinet multikey so that if you do trip the MCB you can open the cabinet and reset it yourself without bothering the site maintenance people, I do that all the time.
 
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Being plunged into the dark when it all goes off, with a visit to the outside connection when it's chucking it down with rain, is a rite of passage! You soon get to know what you can and cannot use at any one time.
 
My van is twenty years old so pretty outdated electric system. I am concerned I may trip the site EHU supply by using too much current. Is there a modern device I can fit that will prevent me overloading the trip should I forget and turn on too many 240v things. I suppose it would have to be adjustable to suit the varying site supplies, 6A 10A 16A etc.
Just use whatever the site has, sensibly, we have been on sites/aires with less than 6a, tripped and reset, learning what you can use max. Ie just about use a travel kettle but no electric boiler use. OK for lights and TV, but not kettle as well and so on. Most sites/Aires with low amps have boxes open so you can reset yourself. It's usually the higher amp connections that are locked and need resetting by management. (y)
 
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Is there a modern device I can fit that will prevent me overloading the trip should I forget and turn on too many 240v things. I suppose it would have to be adjustable to suit the varying site supplies, 6A 10A 16A etc.
The answer to the question is yes. Whether you'll like the rest of the answer I'm not so sure. A 'load shedding relay' will monitor the amps, and will switch off a power relay if the amps limit is exceeded. They are used for example to make sure only one electric shower at a time is used, to prevent overload of house circuits.

I've not heard of it being used in a motorhome. Probably because anyone who can set up such a system knows enough to not need it in the first place.:giggle:

I can imagine, like inverters, they will get better and cheaper as more people want them. The ones I've seen have adjustable amps limit, but it's using a screwdriver to turn a tiny knob in the consumer unit, not something you want to be doing every day.

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The answer to the question is yes. Whether you'll like the rest of the answer I'm not so sure. A 'load shedding relay' will monitor the amps, and will switch off a power relay if the amps limit is exceeded. They are used for example to make sure only one electric shower at a time is used, to prevent overload of house circuits.

I've not heard of it being used in a motorhome. Probably because anyone who can set up such a system knows enough to not need it in the first
I had a Yankee RV with a load shedding panel, a series of lights identifying which items were live. The selection of breaker limit was was only 3 levels. In principle it was an interesting solution but rather clunky and limited. The better solution is something like the Victron remote panel and a multiplus inverter charger, or a Mastervolt combi with their easy view.
 
Just a thought if you have a smart electric meter and remote display.

Why not use it to understand what loads are being drawn when you switch on various items of kit. Wont be super accurate but will give you an indication what's happening and make a decision along the lines of

If water heater on and the water is heating you can boil a kettle but say not have an oil radiator at the same time and so on and so forth.

Remember

Watts = Volts * Amps which is near enough true. (for the Techs Wac = V * A * Pf (Power factor)
 
If you want to see how much power you are using in real time, you could get an energy monitor. The ones that plug in, with a built-in display, are the easiest to start with.

The type I use has a sensor that clips round the incoming mains wire (no electrical connection needed, it's plastic, and just clips loosely round the wire). The sensor plugs into a small transmitter, stuck to the wall near the consumer unit. The display unit can be located anywhere.

The one I use is an OWL Micro+, but that doesn't seem to be available just now. This one is very similar:
Amazon product ASIN B001Q1G4WK
 
We have an Alde Load Monitor fitted which limits current draw from the elh .... it does this by reducing the boiler input if the system is overloaded beyond the preset amperage.
"The load monitor automatically senses and reduces the output of the boiler’s immersion heater. This will prevent the fuse from tripping when several high power electrical devices such as coffee makers, electric kettle. hair dryer or microwave are in use."

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