What impact does low supply voltage have on consumption/bill.

[Mama Noodle]

Like the title says - what impact does low supply voltage/power have on a persons bill? 

 

The electrical supply here has steadily gone to sh*t. Today was extremely hot and my supply was fading in and out like someone was running a huge welding machine in front of my house, which of course they weren't, making my aircons struggle. I can hear it slowing down and speeding up. 

 

And it doesn't even matter what time of day it is. 3 AM the other night listening to the same thing, fade in and fade out. 

I dont have an extremely accurate way to measure my voltage, just a DVOM and it doesn't measure fast enough, but it goes from 195 to 250 volts when its really bad. 

 

Seems to me that every time the voltage drops then comes back up there's a heck of an inrush going on, similar to when you first turn an appliance on. 

[sometimewoodworker]

14 minutes ago, Mama Noodle said:

Like the title says - what impact does low supply voltage/power have on a persons bill? 

It causes premature failure of items so needing replacements.

[Mama Noodle]

14 minutes ago, sometimewoodworker said:

It causes premature failure of items so needing replacements.

 

Drifting off topic but would that apply to items that use AC adapters and wide input voltage ranges? 

[DrDave]

8 minutes ago, Mama Noodle said:

 

Drifting off topic but would that apply to items that use AC adapters and wide input voltage ranges? 

No, if the adapter is a switching power supply, (e.g. stating an input voltage range like 110-240VAC) then the downstream device should be ok.

[Mama Noodle]

What about the impact on a persons power bill? 

[Moonlover]

To answer the O/P's question directly: None. You pay for the energy consumed.

[Mama Noodle]

3 minutes ago, Moonlover said:

To answer the O/P's question directly: None. You pay for the energy consumed.

 

You don't think that low voltage/fading voltage has an impact on consumption? 

[OneeyedJohn]

It could be old faulty devices in your house, for example, when the tap on my sink is turned on and therefore the water heater is activated, I notice a dimming of the light next to my coffee machine. It concerns me, but I don't really know what I can do about it, or whether I need to do something about it.

[Mama Noodle]

10 minutes ago, OneeyedJohn said:

It could be old faulty devices in your house, for example, when the tap on my sink is turned on and therefore the water heater is activated, I notice a dimming of the light next to my coffee machine. It concerns me, but I don't really know what I can do about it, or whether I need to do something about it.

 

I dont have any old or faulty appliances, and this happens all the time, even just sitting watching TV with the air cons on I can literally hear it in the aircon fan speed (High Fan, not auto) 

[DrDave]

Strictly speaking to the impact to your power bill, your bill is based upon the number of "units" consumed (which is actually kilowatt hours).

 

Others can correct me if I'm wrong, but the following is based upon the simple mathematical relationship between Volts, Amps and Watts...

An appliance like an oven that uses 1,000 watts of power running for one hour will consume one kilowatt hour of electricity.  An appliance rated at 1,000 watts at 240V, will draw 4.17 amps (Amps = Watts/Volts).  Typically if the input voltage is reduced to say 200V, then the power consumption will also reduce to 834 watts.

Edited May 16, 2020 by DrDave

[Mama Noodle]

2 minutes ago, DrDave said:

Strictly speaking to the impact to your power bill, your bill is based upon the number of "units" consumed (which is actually kilowatt hours).

 

An appliance like an oven that uses 1,000 watts of power running for one hour will consume one kilowatt hour of electricity.  An appliance rated at 1,000 watts at 240V, will draw 4.17 amps (Amps = Watts/Volts).  Typically if the input voltage is reduced to say 200V, then the power consumption will also reduce to 834 watts.

 

I understand all of the above. Maybe im not wording my question properly. 

Take an air conditioner for example. Its running, maintaining air temp. The voltage/supply drops then comes back up again, drops and comes back up again over and over and it is significant, dimming the lights as it happens. What effect does this have on the affected appliance trying to compensate for the voltage fluctuation all the time and what would this therefore do to the consumption and thus, my bill? 

 

Is there not an inrush when the voltage rises back up again that would otherwise not happen had the supply been stable, thus creating unnecessary consumption and an unnecessary increase in my bill?

[northsouthdevide]

Don't want to sound stupid, but is it only your air con? 

Not the house lights too? 

Maybe your air con is an inverter type and is doing what it's supposed to, or maybe you have the setting on auto? 

There's a lot more people on here that know more about electrics than me, but have you ever heard of a soft start switch? 

Apparently they stop your aircon unit from using a lot of power when they kick in, and make it quieter and more efficient. 

Not sure if it's the solution to your problem, but I just thought I'd throw it in. 

[Mama Noodle]

2 minutes ago, northsouthdevide said:

Don't want to sound stupid, but is it only your air con? 

Not the house lights too? 

Maybe your air con is an inverter type and is doing what it's supposed to, or maybe you have the setting on auto? 

There's a lot more people on here that know more about electrics than me, but have you ever heard of a soft start switch? 

Apparently they stop your aircon unit from using a lot of power when they kick in, and make it quieter and more efficient. 

Not sure if it's the solution to your problem, but I just thought I'd throw it in. 

 

I addressed all of those already, lights are involved, aircon fan speed is fixed and on high, so the inverter action of the motor is not involved, and I measure the voltage at the consumer unit with a DVOM. 

[tjo o tjim]

Any motor connected to line voltage will tend to consume more energy for the same useful work.  A switching power supply like an inverter on your AC compressor (if you have one) will not be effected in efficiency, but the fans will.

 

Overall, you might see a 2-3% increase in energy consumption with an inverter AC, up to about 5% maximum for a traditional AC, across the whole house.  

[Crossy]

At the risk of repeating what's been said earlier. Domestic appliances generally fall in to one of three categories:-

 

Resistive loads - water heaters, kettles, ovens. Their power consumption is related to the square of the voltage (V²/R) and will decrease if the voltage decreases.

 

Electronic loads - Switching power supplies, electronic lighting, "inverter" appliances. These are constant-power devices, the energy consumed does not change with the voltage (until it gets too low to compensate at which point the device shuts down).

 

Induction motors - conventional aircons, fridges and freezers, water pumps, fans (fans are a bit special anyway). Induction motors try to be constant power, but as the voltage decreases outside the specified operating range they become less efficient, increasing the losses (heat) and generally getting upset. This additional heat of course adds to their power consumption and is the factor that can reduce their life if the voltage remains low for long periods.

 

Generally, a varying supply voltage won't affect your bill (the meter measures the energy used), at least not to an extent you're going to notice, but its effects can be annoying to say the least.

 

@Mama Noodle What sort of time period are these variations (length, time between) and we really need to get a better idea how deep they dip? An analog meter is actually better than a digital in this case (and you can film it to show the PEA). Once you have some evidence head off to your local PEA and ask what they can do about it. If it's staying between 195V and  245V (220V +- 11%) they will probably tell you to go away.

 

Next task will be for you to find a solution that can be implemented in your home (an AVR - Automatic Voltage Regulator). Our incoming supply varies between 180V (sometimes rather lower) and 230V but our AVR provides us with a nice constant 220V for everything except the water heaters, and they don't care anyway.

 

Pinned thread here https://forum.thaivisa.com/topic/1008193-installing-an-automatic-voltage-regulator-avr/

 

[Mama Noodle]

35 minutes ago, Crossy said:

Generally, a varying supply voltage won't affect your bill (the meter measures the energy used), at least not to an extent you're going to notice, but its effects can be annoying to say the least.

 

In my head I just can't seem to see how (and I believe you, just struggling with understanding) an air conditioner (for example) trying to cool a room in the heat of the day with varying supply voltage does not equate to an increase in consumption. I get that the consumption is what it is, thats not going to change, but what's hanging me up is that an aircon that is not operating with its required supply, and thus not cooling as well as it should, so its trying to either (non inverter) cycle alot more (increase in consumption that was unnecessary) or (inverter) operate at a higher motor speed/load to compensate because it can't cool the room as well as it can with a stable, constant supply (increase in consumption that was unnecessary). Maybe im way out in left field, but makes sense to me lol. 

 

44 minutes ago, Crossy said:

What sort of time period are these variations (length, time between) and we really need to get a better idea how deep they dip? An analog meter is actually better than a digital in this case (and you can film it to show the PEA). Once you have some evidence head off to your local PEA and ask what they can do about it. If it's staying between 195V and  245V (220V +- 11%) they will probably tell you to go away.

 

The best way to describe the frequency is to imagine a local with a stick welder - stitch welding something nearby. Bog down, speed up, bog down, speed up - kinda quickly like stitching roof metal together. Every time it happens (everyday, multiple times a day, even in the middle of the night totaling 4-5 hours a day, everyday) I picture a dude welding somewhere because it feels just like that.

 

And yea best I can measure here at the moment is 190V to 255V and fluctuating at the frequency noted above. All my stuff is digital so I know im losing accuracy when I measure. 

 

PEA was round the other day, totally agreed that we had low supply and said they would 'file a report' which I know will amount to nothing. 

 

[bankruatsteve]

If this is really bugging you, buy a 10 kVA AVR(AVS) for about B9000 and then you don't need to worry about it.

[Metropolitian]

18 hours ago, Mama Noodle said:

what impact does low supply voltage/power have on a persons bill? 

On the bill from the electric provider (mea/pea/..) nothing noticeable.

 

Electricity usage is measured in power.

If the voltage drops, most appliances would likely draw more currents (and that's where many failures starting as it means heating up the wires) but the power used (power = volt times current) are registered normal.

 

The impact would be more on other bills, from repairs and a little bit on the electricity bill from the  inrush current if the grid voltage went too low and devices turned off (fridges) and on again after a while.

And there are other 'bills' like batteries for your torch and emergency supplies.

And for buying extra protective solutions (AVR, switches,..) if you want to get rid of those issues. Costs whose people living with easy whitegoods like fans and a tv would not consider to spend.

[bankruatsteve]

1 minute ago, Metropolitian said:

 

Electricity usage is measured in power.

Actually it measures energy consumption.  Power over time.  Power is kW.  Energy (as measured by a meter) is kWh.  

[Metropolitian]

17 hours ago, OneeyedJohn said:

It could be old faulty devices in your house, for example, when the tap on my sink is turned on and therefore the water heater is activated, I notice a dimming of the light next to my coffee machine. It concerns me, but I don't really know what I can do about it, or whether I need to do something about it.

Very much voltage drop in the wiring itself caused by higher currents then the rating of the wiring. Especially if the dimming holds on and not just at the start.

A sign to not connect more peripherals in this group, advisably even not having the coffeemachine and the heater running at the same time for a while.

Do you know the amp/watt rating of those two and the cable diameter plus distance in that group going to the consumer unit?

 

[Metropolitian]

7 minutes ago, bankruatsteve said:

Actually it measures energy consumption.  Power over time.  Power is kW.  Energy (as measured by a meter) is kWh.  

I am correct, it is measured in power. At the meter calculated from both volt and current (analog you need two 'attractive mechanism' in the meter, one in series and one parallel).

 

A kW is only kilo (1000) watt, both a form of power from the derivative volt times current.

Energy is in joules, one joule is one watt in one second. Thus one hour of one watt is 3600 joule and one kW-h which is just an unit of energy.

 

For the meter outside your home it is measured as energy consumption, and the dials are in kWh but could theoretically anything made up.

The spinning wheel are mostly 400th of an unit/kWh, meaning the wheel turning 400 rounds before it's a kWh consumed(transported).

The 400 is for the 15(45) meters from Mitsubishi, their bigger brothers wheel turns 200 to complete the unit. Digital meters giving a (led)blib each 'turn of the wheel'.

 

From the solar panels or anything 'generating' it is energy generated instead of consumption and this -can- flow back to the meter outside.

Hence I am not using the term 'consumption' with meters ???? even if the net are the consumer in the way of reverse flow but a 'transport unit' .

 

 

 

[Crossy]

40 minutes ago, Metropolitian said:

I am correct, it is measured in power.

 

Nope, it is measured as energy, actually in Joules but that's not convenient so we use a horrible hybrid the kilowatt hour (kWh). The time factor converts power into energy (1 Watt = 1 Joule per second).

 

1kWh is 3.6MJ 

 

The rest of the post is spot on ????

 

 

[NCC1701A]

to make everyone feel better i took a power hit last week that was more like a long duration voltage drop, maybe five seconds. UPS relays clicking then there was a loud bang and one floor fan started making a terrible sound and one breaker for a different room trips and will not reset now. nothing to do with the fan. so some wiring in this super old house must have finally died but i can't find it.

 

i guess i will have to reroute the plasma relays on deck 12 until i can find the source of the problem.      

[RichCor]

9 hours ago, Mama Noodle said:

The best way to describe the frequency is to imagine a local with a stick welder - stitch welding something nearby. Bog down, speed up, bog down, speed up - kinda quickly like stitching roof metal together. Every time it happens (everyday, multiple times a day, even in the middle of the night totaling 4-5 hours a day, everyday) I picture a dude welding somewhere because it feels just like that.

 

And yea best I can measure here at the moment is 190V to 255V and fluctuating at the frequency noted above. All my stuff is digital so I know im losing accuracy when I measure. 

 

PEA was round the other day, totally agreed that we had low supply and said they would 'file a report' which I know will amount to nothing. 

Gotta wonder if there's a loose connection somewhere (and by somewhere I mean along the transmission route). 

 

If you were to test the voltage at several neighbors (connected the same phase as you) and they had the same erratic voltage measurements then that suggests the issue lays with PEA and their infrastructure. Or your meter. Or the way you're using the meter. Probably PEA.

 

But if the neighbors measured rather steady then I'd suggest checking ALL the screw terminals as I'd suspect something it working its way loose. There was a recent ThaiVisa electrical topic where this was the case.

 

Then again, you could be situated in a location serviced by ancient PEA infrastructure and populated by people who weld in the middle of the night  -- Looking at you, @Crossy!

[Mama Noodle]

29 minutes ago, RichCor said:

Probably PEA

Its PEA, its always been a problem. Today I went 4 hours in the heat of the day with a steady 140V that would barely even turn a fan. 

 

Getting pretty infuriating to be honest. 

[Metropolitian]

2 hours ago, Crossy said:

 

Nope, it is measured as energy, actually in Joules but that's not convenient so we use a horrible hybrid the kilowatt hour (kWh).

 

On that I stand corrected as...

 

2 hours ago, Crossy said:

The time factor converts power into energy (1 Watt = 1 Joule per second).

Right. 'Usage' is the time factor ????

 

Power (watt) * Time = Energy.

Without time, no energy, relative. 555

A angry Thai wife, with a substantial mass is very powerful, but if time stood still there would be no energy.

 

2 hours ago, Crossy said:

1kWh is 3.6MJ 

My mistake, 3600 sec in one hour but the kilo with the watt adds the three zeros with the joules.

[Mama Noodle]

8 hours ago, bankruatsteve said:

If this is really bugging you, buy a 10 kVA AVR(AVS) for about B9000 and then you don't need to worry about it.

 

Whats bugging me is the idea of spending 9k to resolve an issue that PEA should be fixing. I know, this is Thailand, but still. 

 

 

[Crossy]

Before buying anything on the AVR front, please read my pinned AVR thread.

 

[Mama Noodle]

3 hours ago, Crossy said:

The rest of the post is spot on

 

So I guess my problem won't cause any noticeable increase in consumption over having a steady supply and appliances operating at their most efficient? 

[Metropolitian]

2 hours ago, NCC1701A said:

to make everyone feel better i took a power hit last week that was more like a long duration voltage drop, maybe five seconds. UPS relays clicking then there was a loud bang and one floor fan started making a terrible sound and one breaker for a different room trips and will not reset now. nothing to do with the fan. so some wiring in this super old house must have finally died but i can't find it.

 

i guess i will have to reroute the plasma relays on deck 12 until i can find the source of the problem.      

Next time, take a arc path around the fluidic space.

Your impulse drivers don't work out pretty well there.

Ever tried to have a cardio workout under water?

 

For the time being, try bypass the main supply to the port so you can keep enjoying your TV and a mattress is universal to sleep on, even on a bridge.