Workshop Light Efficiency

[jedmc571]

That's interesting about older lamps, I'm a Maintenance Engineer, and recently all our aisle lights started failing, they were almost spot on for life expectancy, How do they do that ?

How long would you run a flourescent for then, I think I might get some new ones, mine were salvaged from a Dentists.

Cheers

Jed

 

[RobertMP]

I manufactured lighting rather than maintained it

Lighting maintenance contractors go to a store and replace every lamp in it in one fell swoop. There are calculations done based on light output and failure rates but the bias is towards output as failures are rare with fluorescents.

Oh and just to pick up on the point of energy efficiency... it is arguably true that the wasted power would contribute to house heating but the heat will be in the wrong place to be of any benefit so I'd suggest saving power is a good option.

T5 lamps are one of the most efficient around currently. (T5 = 5/8ths diameter.. t8 = 8/8th etc.). I have two twin enclosure fittings with 35W T5 lamps and high quality electronic gear totalling around 150W for my single garage workshop and they provide good general lighting. I use additional task lighting for any fine detail work. Lighting the task well is more efficient than trying to light everywhere to that level.

 

[RobertMP]

That's interesting about older lamps, I'm a Maintenance Engineer, and recently all our aisle lights started failing,
Cheers

Jed

usually because something went wrong with the power supply and one phase got over voltage for a while causing lamps on that phase to fail.

 

[woodbloke]

Interesting discussion. I can't contribute much to except to say that I use 4xT5's (doubles) with an older 4' tube over the bench and 60W spots in strategic areas. My 'leccy consumption hasn't noticeably increased due to lighting requirements, but I'd just offer two thoughts, the first of which is that it's an excellent idea to wipe the dust of the filaments from time to time (makes a huge difference) Secondly, if I were using too much 'leccy, SWIMBO would let me know in very short order :shock: - Rob

 

[head clansman]

hi rogers

My point was , if tom hadn't switched every thing off the reading he was getting in his workshop included everything that was running in his home at that time.Wether the meters are acurate is not important you can only go on what that meter tells you.

Now every body stop and think just what is running in the background in your home at this moment in time, Make a list and then go and switch them all off , bet most of you have overlooked and miss things , keep going till the meter wheel stops.


Maybe what tom thought was a high reading actually included many other things as well in his home , so again maybe he wont need to replace any lights at all when he has a reading that included the lights consumption only. hc

 

[Deejay]

Hello Tom

Two things. Firstly, the accuracy of the meter may vary over the range. Try turning on something to increase the 'background' load and do your test again. If you get a different result all you really prove is that the meter isn't very accurate.

Secondly, disconnect all the fittings (bar one) and reconnect them one at a time. It might be one fitting drawing most of the current. Bit of a pain, depending on your wiring, so you could just leave them on for a while and feel them to see if one is getting hotter than the others before you do that.

Cheers

Dave

 

[Racers]

Hi,

The easy way to disconect them it to take the tube out.

Pete

 

[big soft moose]

Hello Tom

Two things. Firstly, the accuracy of the meter may vary over the range. Try turning on something to increase the 'background' load and do your test again. If you get a different result all you really prove is that the meter isn't very accurate.

Secondly, disconnect all the fittings (bar one) and reconnect them one at a time. It might be one fitting drawing most of the current. Bit of a pain, depending on your wiring, so you could just leave them on for a while and feel them to see if one is getting hotter than the others before you do that.

Cheers

Dave

and also check that nothing else is kicking in at the same time - if wifey put the kettle on at the same time that would explain much.

that aside i'm with bob on this there is no way 4 flourecent light tubes should be drawing 500W - either your meter isnt very accurate (which is my feeling given that its just clipped to the outside of the cable not directly connected to the wiring) or there is something badly wrong in your workshop wiring.

edit : tom i just thought isnt the most obvious way of checking what the lights are drawing to use the actual house electricity meter - get swimbo to keep an eye on it while you turn the lights on and check what the increased load is

 

[Deejay]

Hello Pete

Hi,

The easy way to disconnect them it to take the tube out.

Pete

I agree, unless there is a fault on the fitting itself. Remove the wiring and you know that everything is disconnected.

Cheers

Dave

 

[Racers]

Hi,

There isn't much in a flouresent to cause a fault like that and it there was the light wouldn't light, I spent a good few years working on juke-boxes fruit machines etc so flouresent lights are some thing I have worked on a lot.

The problem is probbaly caused by the chokes in the lights affecting the power factor and causing the meter to miss read.
A clamp meter on one of the meter tails would be the best way of measuring the current.


Pete

 

[RobertMP]

Hi,

The easy way to disconect them it to take the tube out.

Pete

generally true but older quickstart and SRS circuits will still draw some power. Electronic ballasts (unless they are really cheap or early designs) will detect the open circuit and shut down... but still draw a little power just as a Tv on standby would. Ordinary switchstart circuits with no power factor correction will be completely disconnected. Those with normal parallel power correction will have a capacitive load with no inductive one to cancel it and hence draw near load current but consume no power.

 

[BMac]

Hi Rogers,

The 'dead leg' thing. I understand what you are saying but in my situation the washing machine is in a building behind the house and about 30 feet from the hot tank so I got a sink installed so that I could run off the cold water between the tap and the tank. There's still some cold water in the flexi pipe going to the machine from the hot pipe but a lot less than if I didn't run most off. I am interested in your solution and will investigate it because it sounds a lot more efficient than mine.

 

[TrimTheKing]

Thing is that 9fingers is spot-on and that these meters are not that accurate.

Got to disagree with Roger and 9fingers on this!

I understand the science so i'm not going to get into an argument about it, but I am using a CurrentCost device (effectively them same thing as Tom has just different manufacturer) and have been running it for 4 months now. I can give you a cast iron guarantee that it matches almost identically (to within 4%) to the readings on my meter over that whole given time period.

That tells me that it's working pretty damn well...

Mark

 

[TrimTheKing]

Hi Rogers,

The 'dead leg' thing. I understand what you are saying but in my situation the washing machine is in a building behind the house and about 30 feet from the hot tank so I got a sink installed so that I could run off the cold water between the tap and the tank. There's still some cold water in the flexi pipe going to the machine from the hot pipe but a lot less than if I didn't run most off. I am interested in your solution and will investigate it because it sounds a lot more efficient than mine.

I don't understand what you guys are saying here. Modern d/w and w/m only have a cold water feed (I have bought 2 new washing machines and 1 new dish washer for our new house and all 3 only have a single cold feed in forcing you to use the leccy device...), so how can running cold water make any difference at all???

Or are you saying you should ignore that and plumb them into the hot feed instead?

 

[RobertMP]

My dishwasher is cold feed only. manual says 'cold' water must not exceed 65 dec C... so I plumbed it into the hot feed. Keeps the cycle time down and saves electric water heating.

 

[TrimTheKing]

My dishwasher is cold feed only. manual says 'cold' water must not exceed 65 dec C... so I plumbed it into the hot feed. Keeps the cycle time down and saves electric water heating.

Ahhh, that explains it then, cheers

 

[9fingers]

Thing is that 9fingers is spot-on and that these meters are not that accurate.

Got to disagree with Roger and 9fingers on this!

I understand the science so i'm not going to get into an argument about it, but I am using a CurrentCost device (effectively them same thing as Tom has just different manufacturer) and have been running it for 4 months now. I can give you a cast iron guarantee that it matches almost identically (to within 4%) to the readings on my meter over that whole given time period.

That tells me that it's working pretty damn well...

Mark

Hi Mark,

I was not trying to say these devices are fundamentally inaccurate. The accuracy will depend on the type of appliances you have and for all I know the manufacturer could build in a factor for typical domestic set up.

They only measure current and convert that to power using a fixed conversion factor. The strength of this is that it makes it cheap and contactless to the housewiring and the weakness is that when some of us use them to draw inferences about power drawn in our workshops some inaccuracies can creep in.

Wizer is using 5 fluorescent tubes which is likely to be more than most households and they can have a particularly poor power factor. Hence the obvious error he was measuring.

Cheers

Bob

 

[TrimTheKing]

Hi Mark,

I was not trying to say these devices are fundamentally inaccurate. The accuracy will depend on the type of appliances you have and for all I know the manufacturer could build in a factor for typical domestic set up.

They only measure current and convert that to power using a fixed conversion factor. The strength of this is that it makes it cheap and contactless to the housewiring and the weakness is that when some of us use them to draw inferences about power drawn in our workshops some inaccuracies can creep in.

Wizer is using 5 fluorescent tubes which is likely to be more than most households and they can have a particularly poor power factor. Hence the obvious error he was measuring.

Cheers

Bob

Hi Bob

Sorry, I have just re-read my post and it came across a bit aggressive, not intentional

I understand what you are getting at and I too have a bit of a pet hate about the power usage of things hence the monitor. I have a Lutron lighting control system which, even with not a single light on in the house, uses the best part of 500-600w!!!! :shock:

It effectively costs me £40-50 a month just for my 'light switch'!

I worked this out by systematically going round the house with the current monitor on switching things off, with SWMBO wathching the usage change, and noting all the values down. Now I have a list of the usage of my devices, but my big issue is that even with only 'essentials' running (fridge, freezer, alarm system etc, and the Lutron) my base usage is about 750w

I really need to talk to a spark who deals in Lutron to see if I can replace this with something that uses lessa s this is ridiculous.

Cheers

Mark

 

[BMac]

Hi Mark,

The machine I have has hot and cold feed. I bought it last year so maybe it was the last of the species.

Brendan

 

[wizer]

Wow been up the hospital all day, lots of information to take in!

I installed the cheapo Screwfix Sylvania ones earlier in the year and they were well worth it.

These look good, thanks. I hope they still have them at that price after xmas.


I need to do some further tests on the house. Like Trim, I've been going round testing everything and the workshop lights are on my high offender list. I've used the meter at all different times a day to get a good idea whats what. With going in for my op next week, i'm not going to be able to do any extensive testing to find out exactly what's sucking the power. They are a mixture of units, I think 2 are new when I moved in, 2 are 2nd hand but newish and one is really old and buzzes like hell.

Our electricity bills are still high, even after cutting the plug off the tumble dryer and taking the fuse out of the underfloor heating in the bathroom. It doesn't even seem to change during summer.

Obviously I expect it to be on the high side as we both are high tech users. I thought the laptops would be a problem but they don't seem to create much activity on the meter.