Ballast for fluorescent lamp

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  #1  
Old 08-17-07, 07:53 PM
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Smile Ballast for fluorescent lamp

Is there any reason that I cannot replace the 2 F40T12 40W lamps of a fixture with 2 F32T8 32W and keep the old ballast?

Rainer
 
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  #2  
Old 08-17-07, 08:26 PM
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yes, because the old ballast is designed for 2 F40T12 40W lamps, not 2 F32T8 32W lmaps.

unless you mean keep it like in your garage of under your stairs, which you are more than welcome to do if you want.
 
  #3  
Old 08-17-07, 08:56 PM
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most 40 watts T-12 ballast useally are restricted to 40 watts only but if you open the lumiaire cover off and see the ballast label it will useally list other bulb size there as well like example 34 watts T-12 , 40watts T-10 those like example that it can use either type of bulbs.

but make a note do not run a mixure of diffrent wattage bulbs on the same ballast because it will overheat it easy or can fail to come on.

and also just want to head up most resdential ballast useally are " low power factor " it useally mean the bulbs will not be at full brightness as the commercal verison is [ kinda hard to expain all the detals and get this forum crowed up ] and typeally resdentail ballast on low powe factor useally are about 50- 70 % brightness vs oc commercal units or electronic ballast as well

if you want really save engery cost and use this lumiaire alot then change the ballast or the whole fixure depending on the cost go with T-8's they are very common nowdays and they will really kick alot of light if used right

Merci , Marc

p.s. the 32 w T-8 have just about the same lumies [ brightness] as 40 watt T-12 is
 
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Old 08-18-07, 02:27 AM
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Marc, while you are on this subject, maybe you can explain the overdrive ballasts used in the newer T-8 6 lamp high bay fixtures. I, myself, have not had a well defined answer as to what the manufacturers are doing to overdrive the lamps. You seem to be our current resident store house of knowledge of florescent lamps.
 
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Old 08-18-07, 09:49 AM
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Thanks

Originally Posted by french277V View Post
most 40 watts T-12 ballast useally are restricted to 40 watts only but if you open the lumiaire cover off and see the ballast label it will useally list other bulb size there as well like example 34 watts T-12 , 40watts T-10 those like example that it can use either type of bulbs.

but make a note do not run a mixure of diffrent wattage bulbs on the same ballast because it will overheat it easy or can fail to come on.

and also just want to head up most resdential ballast useally are " low power factor " it useally mean the bulbs will not be at full brightness as the commercal verison is [ kinda hard to expain all the detals and get this forum crowed up ] and typeally resdentail ballast on low powe factor useally are about 50- 70 % brightness vs oc commercal units or electronic ballast as well

if you want really save engery cost and use this lumiaire alot then change the ballast or the whole fixure depending on the cost go with T-8's they are very common nowdays and they will really kick alot of light if used right

Merci , Marc

p.s. the 32 w T-8 have just about the same lumies [ brightness] as 40 watt T-12 is
Marc, I appreciate your help - Thanks,

Rainer
 
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Old 08-18-07, 10:46 AM
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Fwiw.. I usually found that for the price of a new ballast you can get a whole new fixture for close to, if not cheaper.
 
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Old 08-18-07, 11:34 AM
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When i grew up, 40W was std. No 36 W is used in those old armatures.

In Norway almoast all of theese are made for 220-230 V 50 Hz with a starter.

It will probably work with 32W too. I would try, and follow the temp rise for hrs.

dsk
 
  #8  
Old 08-18-07, 09:23 PM
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Well, most magnetic T12 ballasts were rapid start ( they preheat a filament on the bulb) and most T8 electronic ballasts are instant start ( no preheat). The rapid start fixture will have more wires. Many , but not all bulbs, are rated for instant start OR rapid start, so the bulb does make a difference.

HO ( high output ) bulbs need higher starting voltage and draw more current, hence the greater light output. The bulbs and the ballasts have to be matched types.
 
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Old 08-20-07, 04:18 PM
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Nap;

sorry for a delay to answer the question anyway with highbay/lowbay appaction they used 6 lamp setup but they used very good reflector almost like polished mirror to reflect the light down and by the way the ballast is the same as the standard run of mill electronic ballast

so basically with 6 lamp the total lumines will depending on if that ran on T-8, T-8HO , T-5 , T-5HO so it have few diffrent way to set up the brightness i will give you a quick example

standard 400 watt hi/lowbay lumaire the light will crank out about 32-36,000 lumines when they are new when near end of life [ bulb itself ] will dimmed down to about 25,000 lumines or so depending how long you leave it running and how often you change the bulb

ok for the hi/lowbay floursecent lumiaire this get little tricky here what we do is add the sum total of lumines of each bulb:

typical T-8's useally run 3200 lumines each bulb X 6 bulb total = 19200 total
but dont get me wrong on this one they do shine the light downward compared to old style it shine the light almost everywhere

for other bulbs like T-5HO and T-8HO they have much higher lumines level and it will be slighty dimmer than new 400 w MH but when to get end of life the flourscent will outshine it ;


594tough:

the diffence between the HO and standard bulb on flourscent is the amparage [ current ] but to start up voltage it is the same of both of it

let me give you the quick ex, 4 footer [ 40 watt type ] will have roughly 270 volts running thru the arc tube to start up it will take up to 500 v for short duration but here the instering twist the current on 40 watts run of mill T-12 bulb is 380-400MA [ millisamp] while the HO verison of the same tube the voltage is the same only the diffrence is the current the HO is 800 MA and there is one oddball beast which most of you dont see this expect in Industrail area it have 1500 MA aka SHO or VHO verison that part we dont see it not much any more around here it getting history with some type of bulbs

the standard 400MA bulbs is 40 watts , the standard 800 MA bulbs is 60 watts and VHO high as 120 watts this based on 4 foot T-12 bulbs but genrally each manufacter have it own guideline for wattage and type etc

i hope it will help ya some of it

Merci , Marc
 
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Old 08-20-07, 11:43 PM
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Marc:
sorry for a delay to answer the question anyway with highbay/lowbay appaction they used 6 lamp setup but they used very good reflector almost like polished mirror to reflect the light down and by the way the ballast is the same as the standard run of mill electronic ballast
===========

When I went to buy a new ballast, the supply houses (more than one) claimed they are not the same ballasts as a standard T-8

The supply house has termed them an "overdrive" ballast. Not sure what they are doing different. I'll have to dig into it a bit more from here.

btw- the VHO lamps are most often used in freezers or outdoor signs in my experience.
 
  #11  
Old 08-21-07, 08:34 PM
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Nap let me fill you in few more details the HI/LOW bay floursecent lumiaire useally have T-8 HO and T-5 HO and the electronic ballast can be standard setting or" overdriven " which you have to look at the " ballast factor " anything below 1.0 is standard but if you see ballast factor like this 1.15 or 1.25 that mean it overlight by 15 or 25 % brighter with slighty more wattage

and most HI/Low bay flourscent lumiares useally have more than one ballast in there some have two some have 3 ballast depending on the setup there are few combations it can be used and also they have one nice feature that in wharehouse storarage or long asile area they can either dimmed or turn on/ off with motion sensor to save even more power

noted that when i say dimmed that mean have one or two ballast turned off depending on the conferation is also the other thing we have to consderation is the tempture limited on upper and lower end of the tempture specturm they seems little picky with it espcally that true with the T-5's

i allready installed quite few of them both t-5 and t-8 verison [ note that most used HO verison of each tube ]

if you have more question please do let me know


Merci , Marc

note that most HO is very common in cold and signage useage but the VHO is not too wide spread but still around here but the cost of each tube sometime it is not worth a [ you know what i will say here ] with it

also the 215 w VHO 8 footer cost about almost 40 buck and they have only 12K hours life
 

Last edited by french277V; 08-21-07 at 08:37 PM. Reason: add few more info
  #12  
Old 08-27-07, 09:32 AM
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T8 Lamps with T12 ballast

This is a response to the original question. I had several a single-tube fixtures with ballasts listed for F40T12 and F30T12 (among other T12s). The electrical store assured me that I could use F32T8 lamps in these fixtures.

The did work, but not very well. The lamps did not seem to last nearly as long as they should. And, were often slow to come on. I used these fixtures about 2 years.

I recently replaced the ballasts with ones labeled for F32T8. This seems to work much better, but it has not been long enough to be sure. Lamps which were coming on VERY slowly, now operate normally.

So, it seems to me that the original configuration was bad for the lamps. I think this agrees with some of the previous messages. How about the ballasts? Any reason to believe that using the T8 tubes harmed the T12 ballasts?

Willie
 
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