Current (Amps) Problem ?

[snippit]

Help please





living near the end of a very long overhead route, the supply has been very good over the years considering.

However , recently, at odd times, when pluggin in a high power device ( 3kw heater ) the trip is activated. At other times the devices work OK.

Am I right in assuming that its a current problem, where 60amps feed to the property is being affected by high usage elsewhere (unknown) and the current to the house drops to around 15amps or so, thus inducing the trip switch activation when a higher current is required?

Is there a device that I can plug into a mains plug which measures the current amperage?

Thanks

 

[ricicle]

What is written on the device which trips?
It is voltage that drops over long distances, particularly when other loads are added by other users.Current is proportional to voltage (normally) so if the voltage does fall then so will the current but not to the figures you are quoting (unless you have a serious problem)

You would be better off, if you are competant to do it safely, measuring the voltage to your property and if it dropping significantly(>10%) when your largest load is connected (cooker/shower) then you need to speak to your DNO (local distribution company)

Have you had the wiring checked to see if you have any faults on your wiring (these could be intermittent!)A competant electrican should be able to test this for you as well as checking your incoming supply to your consumer unit.

 

[snippit]

Thanks for your informative reply ricicle

What is written on the device which trips?

Mira shower, 9.8kw's - 50 amps.
oil radiator, 2kw.
heated pan, 1kw
and a few more less than 1kw.

It is voltage that drops over long distances, particularly when other loads are added by other users.Current is proportional to voltage (normally) so if the voltage does fall then so will the current but not to the figures you are quoting (unless you have a serious problem)

I believe it is a serious problem for reasons which I'd rather not disclose

Have you had the wiring checked to see if you have any faults on your wiring (these could be intermittent!)A competant electrican should be able to test this for you as well as checking your incoming supply to your consumer unit.

An electrician left yesterday after checking all the wiring ,giving a clean bill of health for the house wiring for this very problem.

As you see form the devices I've listed, the shower is direct wired to the mcb with 10mm copper.

Most of the time, the devices work fine.


The electrician told me that the whole system would trip if more current (amps) was requested than the supply gave.... if I used the cooker whilst the shower was operational etc.

I'm not competant to measure volts like you suggest, i wish there was something I could just plug in

 

[Space cat]

What ricicle meant was "What is written on the trip that is activated?" I'm assuming that the 'trip' in question is in or around your consumer unit (fusebox).

Is there a device that I can plug into a mains plug which measures the current amperage?

Unfortunately not. You can however get a reasonable estimate of your total current consumption by watching your meter.

1) Time how long it takes to clock up one unit (kilowatt hour).

2) Convert the time into seconds and divide it into 3600 to get your power consumption in kilowatts.

3) Multiply the result by 4.3 to find your total current in amps.

That last step is only an estimate because it assumes two things: voltage = 230V and power factor = 1 but it'll be close enough.

The electrician told me that the whole system would trip if more current (amps) was requested than the supply gave.... if I used the cooker whilst the shower was operational etc.

I'm not sure exactly what (s)he meant by that but it's possible to blow the main service fuse by using too many power hungry devices at once. This will leave you with no power at all until the nice man from the Electricity Board comes to fix it.

 

[Fred_Fanackapan]

Is this of any use?
http://www.efergy.com/en/index.php

It clips onto your meter tail and measures the total current taken. It works out the wattage by assuming a given voltage and a power factor of 1.

 

[ban-all-sheds]

Am I right in assuming that its a current problem, where 60amps feed to the property is being affected by high usage elsewhere (unknown) and the current to the house drops to around 15amps or so, thus inducing the trip switch activation when a higher current is required?

No - sorry - that is complete and utter nonsense.

 

[RF Lighting]

It is voltage that drops over long distances, particularly when other loads are added by other users.Current is proportional to voltage (normally) so if the voltage does fall then so will the current but not to the figures you are quoting (unless you have a serious problem)

I believe it is a serious problem for reasons which I'd rather not disclose

Why will you not dislose it?

The more information you can give us, the more chance we have of working out what may or may not be the problem.

Even supposition. This can be seen as a possible, or ruled out. Either way it helps.

 

[Steve]

One thing the OP needs to realise is that his house is not supplied with 60 amps. It is supplied with 230 volts at 50Hz AC. The supplier determines that based on the size of their supply cables and equipment, the MAXIMUM he will be able to take from their supply is 60 amps, so they have fitted a 60 amp main fuse.

He can draw as much current as he wants, up to 60 amps. Nothing will stop him doing that, unless the combined loading of all the properties on his substation trip the substation fuses - this is VERY rare, since the substation fuses are mainly there for short circuit faults.

What may put a dent in his supply, however, is someone else on the same substation using a large appliance (think farms with large electrical equipment). A heavy load will affect voltage supply to everyone on the substation, especially where long overhead routes are concerned.

However, voltage drop normally manifests itself with the main symptom of making the lights go dim. It wont normally trip any MCBs or RCDs.

I believe it is a serious problem for reasons which I'd rather not disclose

why?