Load Testing

[allybally69]

Hi, ive been asked to carry out Load testing on a whole shop to see if the existing supply cable can take more load, now I'm familiar with working out loadings with the on site guide, but the conversation I had led me to believe this can be measured with a clamp meter, surely this way is not very accurate and it depends on what's plugged in at the time or am I completly barking up the wrong tree, some advice would be much appreciated

Thanks

 

[Besoeker]

Hi, ive been asked to carry out Load testing on a whole shop to see if the existing supply cable can take more load, now I'm familiar with working out loadings with the on site guide, but the conversation I had led me to believe this can be measured with a clamp meter, surely this way is not very accurate and it depends on what's plugged in at the time or am I completly barking up the wrong tree, some advice would be much appreciated

Thanks

Depends on what is plugged in an actually drawing power I suppose. I think you would need to record it over a 24 hour period. For industrial that's what I would do.

You could add up the power of everything connected but not all will nezccesarily run at thze same time. If by shop you mean retail then refridgeration units will cycle on an off. You would need to apply a diversity factor.

 

[allybally69]

Great thanks, the only thing that's in there is lights, fixed heaters, small undersink water heater, a computer desk and lots of sockets free for anyone to use

Thank you

 

[Octopus]

How much "more load" do they want to add?

Maybe you need to work out diversity (but don't rely on the IET / OSG calculations) AND visit at "peak times" and use a clamp meter.....

 

[Andy78]

If the job can afford it, a load monitor/data logger hired for a week or two will yield the most accurate and comprehensive picture of the actual sausage.

 

[Octopus]

Great thanks, the only thing that's in there is lights, fixed heaters, small undersink water heater, a computer desk and lots of sockets free for anyone to use

Thank you

What do they plug in?

What size is the DNO fuse?

 

[SparkyChick]

What do they plug in?

That is exactly what I was wondering.

lots of sockets free for anyone to use

What exactly is this place? A coffee shop where people can plug their laptops in and such like?

 

[allybally69]

Yeah its a coffee shop, it will just be phones and laptops id hope, I have a meeting with the client in 2 weeks time so will find out more then

 

[Andy78]

Yeah its a coffee shop, it will just be phones and laptops id hope, I have a meeting with the client in 2 weeks time so will find out more then

The large loads will be the coffee machine/s, wall heaters, and under counter water heater. I would assume that these would be the bulk of the existing loading and on pretty much all of the working day, as well as the lighting of course.
Having said that, the alterations sound quite minimal in extra load.

 

[HandySparks]

If the job can afford it, a load monitor/data logger hired for a week or two will yield the most accurate and comprehensive picture of the actual sausage.

If it's just load current you want to record, than one of the cheap domestic energy monitors will do the job. I have an Owl USB one which will allow you to download power readings at one minute intervals for a month.

 

[GMES]

Data logger every time, I shelled out for the fluke 1730 last year and although nearly 2k it has paid for itself already, Fantastic piece of kit. you can log from as little as 10 minutes up to 3 months. then just either print or email all results to customer.
https://www.google.co.uk/url?sa=t&r...AJBpzOKi16mU1CBGilnO1A&bvm=bv.148073327,d.ZGg

 

[HandySparks]

Data logger every time, I shelled out for the fluke 1730 last year and although nearly 2k it has paid for itself already, Fantastic piece of kit. you can log from as little as 10 minutes up to 3 months. then just either print or email all results to customer.
https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwj947L1uKvSAhVlK8AKHb0OCtgQFgg_MAA&url=http://www.fluke.com/fluke/uken/power-quality-tools/logging-power-meters/fluke-1730.htm?pid=77038&usg=AFQjCNGnHjRhAJBpzOKi16mU1CBGilnO1A&bvm=bv.148073327,d.ZGg

For the purposes of the OP, what would be the benefit of spending £2k rather than £50? (plus a bit for two more current clamps if three phase).

 

[Besoeker]

For the purposes of the OP, what would be the benefit of spending £2k rather than £50? (plus a bit for two more current clamps if three phase).

A record over a period of time rather than an instantaneous value.

 

[HandySparks]

A record over a period of time rather than an instantaneous value.

As I said in post #10, my cheap energy recorder stores electrical loading at one minute intervals over a one month period (which you can download to a pc and import into a spreadsheet).

Edit:
Here's a snapshot of a spreadsheet of my own electricity consumption for the second half of December:
View attachment 35621

 

[GMES]

@HandySparks Besoeker has given a good enough answer for me, At no point did I suggest the op should spend 2k, these units are for hire at 100-150 per week in fact mine is for hire for 100 a week lol, which is how it has paid for itself.
I bought mine because all we do is Ind/comm so are constantly either monitor factories for energy saving solutions or for same reason as above it is on a customers factory at the moment to see what spare he has in his 800amp supply.