TIP: How to check your electricity load/drain without a smart meter or monitor

Glum

Someone has probably posted this before but it is very useful if you have problems with metering, need to reduce standby drain, or you suspect someone is drawing power from your circuit.

If your electricity meter has a flashing red light:
As the consumption increases, the time between flashes gets shorter. If you see 1000 imp/kWh printed near the light, then you can simply calculate the load in kW by dividing 3.6 by the number of seconds between flashes. For high load devices like ovens or heaters, the time between flashes is very short so measure the time for ten flashes then divide by ten to give the duration of one gap in seconds.

In the example of a 2250 Watt kettle, the total time for 10 flashes is 16 seconds, which is 1.6 seconds per flash) so:
3.6 / 1.6 = 2.25 kW (2250 Watts).

Other examples:
Fridge: 20 seconds between flashes = 0.180 kW or 180 W
Small lamp: 360 seconds = 0.010 kW or 10 W
Both switched on together would be 18.95 seconds i.e. more devices gives faster flashing.

Note that this simply calculates the power in kW; if you use a 1 kW device for one hour then you have consumed 1 kWh of energy which is what you pay for.

This method is very accurate but only as accurate as your stop watch. If you fall asleep while waiting for a flash, you are probably using no electricity, or there is a power cut!

k_man

Glum said:

Someone has probably posted this before but it is very useful if you have problems with metering, need to reduce standby drain, or you suspect someone is drawing power from your circuit.

If your electricity meter has a flashing red light:
As the consumption increases, the time between flashes gets shorter. If you see 1000 imp/kWh printed near the light, then you can simply calculate the load in kW by dividing 3.6 by the number of seconds between flashes. For high load devices like ovens or heaters, the time between flashes is very short so measure the time for ten flashes then divide by ten to give the duration of one gap in seconds.

In the example of a 2250 Watt kettle, the total time for 10 flashes is 16 seconds, which is 1.6 seconds per flash) so:
3.6 / 1.6 = 2.25 kW (2250 Watts).

Other examples:
Fridge: 20 seconds between flashes = 0.180 kW or 180 W
Small lamp: 360 seconds = 0.010 kW or 10 W
Both switched on together would be 380 seconds.

Note that this simply calculates the power in kW; if you use a 1 kW device for one hour then you have consumed 1 kWh of energy which is what you pay for.

This method is very accurate but only as accurate as your stop watch. If you fall asleep while waiting for a flash, you are probably using no electricity, or there is a power cut!

Wouldn't both on (180W + 10W = 190w) be 19 (18.947s) not 380s?
(It would flash less often with more devices on)

Glum

Doh! Thanks. I added the times and not the power but with more devices it flashes more often. I will correct the original.