Measuring electric consumption

[Buckman]

When on a site whether metered or not we would be interested in monitoring our consumption and are looking for something suitable. I came across this on another forum and wonder if anyone on here has use one? See https://www.amazon.co.uk/DollaTek-80-260V-Amperage-Voltmeter-Multimeter/dp/B092VYQ697/ref=asc_df_B092VYQ697/?tag=googshopuk-21&linkCode=df0&hvadid=535933031447&hvpos=&hvnetw=g&hvrand=8864889650277070008&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9046654&hvtargid=pla-1393600516042&psc=1

 

[littlebasher]

Reminds me, i have an identical one sat in my garage for the last 2 years that I've been meaning to fit !

 

[Gafferbill]

......I've fitted such a unit and they work well once fitted.
Finding a suitable place to site the display unit may be difficult as they need to be prominent and easy to read.
You are dealing with mains electricity so you have to know what you are doing for a safe installation.
The actual installation of the sensor unit is not straight forward as it only senses on the live (brown) wire and only that wire has to pass through the middle of the sensor.
This sensor needs to be fitted immediately after the mains supply enters the caravan.
My sensor is fitted in a sealed plastic box under one of the front seats.
The display unit is above a cupboard in the kitchen area.

 

[Jcloughie]

I fitted a similar unit. It worked very well but showed too much info, I am now sorry I didn't go for a simpler read-out something like this.

As Gafferbill says, it means passing the incoming live cable through the ring. Then also providing a live supply to the unit. Fine if you feel competent.

John

 

[SteveW]

When on a site whether metered or not we would be interested in monitoring our consumption and are looking for something suitable. I came across this on another forum and wonder if anyone on here has use one? See https://www.amazon.co.uk/DollaTek-80-260V-Amperage-Voltmeter-Multimeter/dp/B092VYQ697/ref=asc_df_B092VYQ697/?tag=googshopuk-21&linkCode=df0&hvadid=535933031447&hvpos=&hvnetw=g&hvrand=8864889650277070008&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9046654&hvtargid=pla-1393600516042&psc=1

We got driven slowly mad recently trying to use a 10A supply, it’s like juggling with a kettle, water heater and space heating. So easy to forget and trip the power! Put the heating on gas in the end. Anyway it inspired me to get a current transformer to homebuild a meter. That ‘s as far as the project has got so far. Maybe one day. Needs to display watts used so everyone can understand the available power, start to flash the display when near a set limit maybe. Finally the device needs to be able to beep and chop the power to the water heater or heating as it sees fit via a relay if needed. All good fun. The front end electronics needed is pretty easy, but caravan projects like this end up in a long queue here!

Steve

 

[Mr Plodd]

I have one, does what it says on the box.

 

[SteveW]

Looks like I might be trying to reinvent the wheel. Though auto control of the high power appliances might be a nice bonus

Steve

 

[ProfJohnL]

Looks like I might be trying to reinvent the wheel. Though auto control of the high power appliances might be a nice bonus

Steve

A company I worked for looked at trying to do this, and whilst it might seem simple, deciding which appliances to shut down , and when is not as easy as you might think. What mix of appliances might be right for one person is wrong for others.

Some appliances don't take kindly to being switched off by cutting the power, they need to be turned off in a particular way (computers for example) and if the TV goes off when you turn a light on will cause annoyance.

I'm not saying it can't be done, just that it was a lot more involved than it first looked.

 

[RogerL]

A company I worked for looked at trying to do this, and whilst it might seem simple, deciding which appliances to shut down , and when is not as easy as you might think. What mix of appliances might be right for one person is wrong for others.

Some appliances don't take kindly to being switched off by cutting the power, they need to be turned off in a particular way (computers for example) and if the TV goes off when you turn a light on will cause annoyance.

I'm not saying it can't be done, just that it was a lot more involved than it first looked.

One of our favourite sites only has a 6A supply to the pitches with the best view - we find it only a mild inconvenience - heating set to 1kw and then switched off while using the microwave or the kettle.

 

[SteveW]

A company I worked for looked at trying to do this, and whilst it might seem simple, deciding which appliances to shut down , and when is not as easy as you might think. What mix of appliances might be right for one person is wrong for others.

Some appliances don't take kindly to being switched off by cutting the power, they need to be turned off in a particular way (computers for example) and if the TV goes off when you turn a light on will cause annoyance.

I'm not saying it can't be done, just that it was a lot more involved than it first looked.

I do see the challenges. Also a big difference if trying to make a saleable product and all that entails safety wise. I envisaged just cutting heating, water heater or both, keeping it simple and unlikely to cause problems. I guess the no volt power fail etc situation would have to be considered in a commercial product. I can see it getting quite involved. For DIY one off use maybe simpler though

Steve

 

[ProfJohnL]

I do see the challenges. Also a big difference if trying to make a saleable product and all that entails safety wise. I envisaged just cutting heating, water heater or both, keeping it simple and unlikely to cause problems. I guess the no volt power fail etc situation would have to be considered in a commercial product. I can see it getting quite involved. For DIY one off use maybe simpler though

Steve

I'd venture to suggest if your on a 6A site, it would be prudent to use gas for space and water heating, including a hob top kettle rather than an electric one. whats left in most caravans would probably be less than 6A.

 

[Buckman]

We got driven slowly mad recently trying to use a 10A supply, it’s like juggling with a kettle, water heater and space heating. So easy to forget and trip the power! Put the heating on gas in the end. Anyway it inspired me to get a current transformer to homebuild a meter. That ‘s as far as the project has got so far. Maybe one day. Needs to display watts used so everyone can understand the available power, start to flash the display when near a set limit maybe. Finally the device needs to be able to beep and chop the power to the water heater or heating as it sees fit via a relay if needed. All good fun. The front end electronics needed is pretty easy, but caravan projects like this end up in a long queue here!

Steve

Our caravan does have a load monitor that can be set between 4 and 16amp and we have found this very handy on French and Spanish sites. Generally in the UK we have it set to 10amp.

Besides heating, it is the fridge that probably has the highest consumption followed by the 2000w George Foreman which we use for about 10 -15 minutes in the mornings for breakfast. Hardly ever use the microwave which I think is 800w and if we do it is only for about 10 minutes.

 

[SteveW]

I'd venture to suggest if your on a 6A site, it would be prudent to use gas for space and water heating, including a hob top kettle rather than an electric one. whats left in most caravans would probably be less than 6A.

The problem for me is not so much 6A sites when you know that the power is really only good for TV and fridge mostly, it’s pretty straightforwards regarding the decision to use gas there. It’s the more common 10A feeds where the temptation is to try to use AC for water and kettle additionally that tend to cause us accidental trips. A small electric kettle is a great plus, but the Achilles heel if using mains for anything else much,

Steve

 

[SteveW]

Our caravan does have a load monitor that can be set between 4 and 16amp and we have found this very handy on French and Spanish sites. Generally in the UK we have it set to 10amp.

Besides heating, it is the fridge that probably has the highest consumption followed by the 2000w George Foreman which we use for about 10 -15 minutes in the mornings for breakfast. Hardly ever use the microwave which I think is 800w and if we do it is only for about 10 minutes.

I guess working on 10 amps you tend to juggle a bit?

Steve

 

[Buckman]

I guess working on 10 amps you tend to juggle a bit?

Steve

Nope not at all. When on 6amp sites in Spain we had the air con running and fridge on gas. Hot water heating turned off during the day. If boiling kettle, air con turned off. You learn to manage.

 

[RogerL]

Our caravan does have a load monitor that can be set between 4 and 16amp and we have found this very handy on French and Spanish sites. Generally in the UK we have it set to 10amp.

Besides heating, it is the fridge that probably has the highest consumption followed by the 2000w George Foreman which we use for about 10 -15 minutes in the mornings for breakfast. Hardly ever use the microwave which I think is 800w and if we do it is only for about 10 minutes.

Microwaves are misleading - 800w is the output rating, the input/consumption will be 1200-1600w

 

[Buckman]

Microwaves are misleading - 800w is the output rating, the input/consumption will be 1200-1600w

Isn't that only on initial start up before settling down to 800w?

 

[ProfJohnL]

Isn't that only on initial start up before settling down to 800w?

It's largely the case, but many microwave, especially the cheaper ones modulate the heat input into the oven by continually turning the magnetron on and off, so the power surge can occur many times during the cooking cycle.

Also the surge current isn't instantaneously on and off it can be over several cycle's of mains power and in conjunction with other loads could be enough to trip an MCB.

 

[Buckman]

It's largely the case, but many microwave, especially the cheaper ones modulate the heat input into the oven by continually turning the magnetron on and off, so the power surge can occur many times during the cooking cycle.

Also the surge current isn't instantaneously on and off it can be over several cycle's of mains power and in conjunction with other loads could be enough to trip an MCB.

Thanks. The caravan has the cheap Daewoo fitted so makes sense however we hardly ever use the MW.

 

[Buckman]

......I've fitted such a unit and they work well once fitted.
Finding a suitable place to site the display unit may be difficult as they need to be prominent and easy to read.
You are dealing with mains electricity so you have to know what you are doing for a safe installation.
The actual installation of the sensor unit is not straight forward as it only senses on the live (brown) wire and only that wire has to pass through the middle of the sensor.
This sensor needs to be fitted immediately after the mains supply enters the caravan.
My sensor is fitted in a sealed plastic box under one of the front seats.
The display unit is above a cupboard in the kitchen area.

I have been looking closer at the unit again, but where do you see your actual consumption? Is this the section marked "power"? Does it reset to zero when you unplug the EHU or is this something that has to be done by yourself?

 

[Jaydug]

I have been looking closer at the unit again, but where do you see your actual consumption?

I have my meter fitted in the space where the radio once was fitted. I didn't use the radio so I removed it. A new panel was made up and the meter was fitted into that. The coil and extra wiring are housed where the radio used to sit.



Of the four groups of figures, the top left is the present voltage. The top right shows the amperage draw, the bottom left the consumption in wattage, and the bottom right, the accumulative amount in kWh. The latter figure can be set to zero at the start of a site stay and reset at the end of the stay. An alarm can be preset to sound if a given wattage draw is exceeded. All the changes are done through a tiny button within the white circle I've added.

The meter becomes particularly useful when electrical appliances are automatically switched on: eg: the water heater, the fridge and charger.

 

[Jcloughie]

I found that the one I fitted, which was similar to Jaydug’s, was good for educational purposes. OH had no idea as to what appliance consumed most. Mine did not have an alarm, that sounds a good idea.

When on low amp sites, ie France. We just got in the habbit of turning the Alde panel off whenever the kettle went on. Of course we wouldnt be using heating at that time so that system worked fine.

John