Above question reads " ....... 100w Mercury Vapour fixtures ..." but
then reads "can I put in a 50w MV bulb" i.e. single bulb. So not sure
if there is one 'fixture'; or a number of 'fixtures'.
However: Per fixture:
a) At 10 cents per k.watt hour you will save 0.5 cents for each hour
the lamp is on.
b) At 20 cents per k.watt hour you will save 1.0 cent per hour lamp is
So if lamp is on every night for say 10 hours;
a) 365 x 10 x 0.5 = 1825 cents or $18.25 saving per per year.
b) $36.50 per year
If lamp is only on occasionally the saving will be much smaller.
PS. This question sounds a little phishy! Was this a troll???????????
Note: Is ransley .......@yaoo etc. not a frequent (and
knowledgeable?) contributor to this forum?
Troll? No ive cut electricity usage in every building I run 50-60% by
use of Cfls, different location of Photosensors and timers on
equipment. I am 14.25 kwh and going up again, I know of no area that
is in fact .10c kwh. 100w 24x7 for me costs about 10$ a month. 50w =
about 5 a month. At 12hrs a day I will save 2.5$ a month. Since I need
a new bulb anyway its adds up in commercial use when you have alot of
MV lights outside. With a building, waste and my profit is paying the
utility co. 30$ will get me a new Cfl and fixture and save me over the
years. Its the small things you do that add up to save on utilities.
On Feb 18, 12:21 am, firstname.lastname@example.org wrote:
Ive had good luck with HD brand Invision, and they have a 7 yr
warranty, so I might have and endless replacement supply free. I have
about 70 HD cfl bulbs in use 2 years with maybe 3 burnouts , 20 on
photocell full time. I am refering to 9-13w cfl and 15-22w cfl floods,
all light at -10f but the floods take about 10 min at -10f to be full
bright so forget the motion sensor with the floods. What was barn
Voltage when it didnt fire? I am 117-120v. Often I get the HD 9w cfl
at about 1$ each because of Com Ed subsidies through HD. Popular
Mechanics magazine rated HD Invision Soft White in the green pack as
good or better than incandesant in skin color rendition. Its an old
article in the home section. With HDs 7yr warranty, try em, and make a
copy of the reciept so you are covered.
Never do this becuase the ballast is designed to deliver a certain voltage
and current to the bulb. The ballast would attempt to drive the same current
into the smaller bulb. The bulb could fail early or even explode. The
ballast may overheat and burn out.
From what I hear, MV bulbs, ballasts and fixtures will no longer be sold in
the US. Replacing it with a CFL fixture may be a better option. MV is not
really a very efficient light source anyway.
I thought a ballast might deliver what is demanded on it, but I dont
know ballast design. A lower watt Cfl fixture is my best option, ones
I saw at HD allow in water and hold it in the lens when its in a
horizontal position, I need to shop.
On Feb 17, 8:00 pm, email@example.com (Don Klipstein) wrote:
Don I see you are quoted on Wikipedia, thats good. MV from what I see
are 55-60 LPW about the same as CFL. What is much more efficient than
that in a soft White Color for an exterior flood fixture in maybe 35w.
HP sodium? I want to keep watts consumed as low as possible.
You recommend Daylight CFL for exterior light but HDs brand show a
lower LPW rating for Daylight vs Soft White flood so I am confused and
buy Soft White, plus I like the way they lite up residential. I wonder
if the charicteristics of Daylight make it perceptably brighter even
with lower LWP rating. For security lights you recommend the
"Daylight" cfl rating, like HDs bulb?. You feel will they be
percieved as much brighter?
Do not put in a bulb other than 100W mercury. A 50 watt one will be
overpowered, probably receiving something like 90 watts. 50 watt operates
with higher mercury vapor pressure (IIRC around 6 or 7 atmospheres) than
most others, and can easily explode if seriously overpowered.
To save power, you have to replace the entire fixture, or at least the
ballast as well as the bulb.
Use only bulbs having an ANSI ballast compatibility code same as at
least one on the ballast or fixture. Violating this can lead to
overpowering or underpowering of the bulb, and/or inability to start or
unreliable starting or starting becoming unreliable after the bulb has
been broken in. Overpowering/underpowering is even possible with
mismatch between 2 different types of same wattage - such as 2 different
150 watt pulse-start high pressure sodium versions. Check the ANSI
"ballast compatibility" codes!
Also, replacing a 100 watt mercury with a 50 watt one may change the
light distribution pattern because the light source is shorter and may be
closer to the base.
- Don Klipstein ( firstname.lastname@example.org)
I can only throw this out for ppl that have HPSodium fixtures...where
I work we have 70W fixures and the guy before me bought 50W fixtures.
I have been buying 50W bulbs (as replacements in both) and they all
seem to be equally bright and no premature failures (been using them
for about 3 yrs)
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