# Indicator light bulb 30V



## Tozguy (Dec 5, 2020)

My lathe has a small 30v bulb that keeps burning out. This is a witness light that is on while there is power to the lathe. 
The only replacement bulbs I have found so far are rated 28v but they burn out even more quickly. Apparently 30v bulbs are not very common here in North America so what to do? 
It is a minor problem but one I would like to solve permanently and move on. Any ideas on where to find the right bulb?
Would a higher voltage bulb last longer?


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## Downunder Bob (Dec 5, 2020)

Tozguy said:


> My lathe has a small 30v bulb that keeps burning out. This is a witness light that is on while there is power to the lathe.
> The only replacement bulbs I have found so far are rated 28v but they burn out even more quickly. Apparently 30v bulbs are not very common here in North America so what to do?
> It is a minor problem but one I would like to solve permanently and move on. Any ideas on where to find the right bulb?
> Would a higher voltage bulb last longer?



Yes, but it won't be as bright, see if you can get a 32V bulb, they used to be common, but not so much now.


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## Alcap (Dec 5, 2020)

What base # is it ? Reason I ask in LED bulbs seem to be a little more flexible in voltage maybe that would be another option


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## Tozguy (Dec 5, 2020)

This is the type of bulb base required.








						CEC 1.7W 14.4V 0.12A G3.5 Mini Bulb
					

CEC Industries brand automotive and indicator lamp.  1.7 Watts and 14.4 volts.  G3 size and shape, miniature bayonet base.




					www.bulbs.com
				



There seems to be a good selection of elongated bulbs but I need the small round bulb like shown in the link above. Thanks for helping.


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## foleda (Dec 5, 2020)

Tozguy said:


> This is the type of bulb base required.
> 
> 
> 
> ...



This 32 v one from McMaster will be a little dimmer but will last much longer than one rated for 30 v.


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## tq60 (Dec 5, 2020)

Google is your friend...

We needed 24 volt led replacement and was not sure of base type so just started searching and found many interesting things but finally found our base number, next, search base, voltage led and Amazon has many variants.

What we found was exact same size with led, no power supply base, assuming just resistor and led.

Was rated as dc only but works fine on a.c..

The voltage can vary greatly and you can simply add a resistor in the supply line to lower the voltage if needed.

Sent from my SAMSUNG-SM-G930A using Tapatalk


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## Tozguy (Dec 5, 2020)

Dave, checked out your link but found that the bulb is too large.
The OEM bulb is only .425'' in dia. 
There probably is a replacement available from the lathe people but that would be a last resort.
My local electrical/electronic supply has all kinds of catalogs for bulbs but was stumped for this particular lamp.
If nothing pans out I might just install a 240 volt light somewhere overhead instead.


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## markba633csi (Dec 5, 2020)

You could make an led replacement using the base from one of the burned out bulbs, an led, and a resistor of about 1500 ohms at 1/2 watt or so.
like this:  (you could tuck it in a little better than I drew it, and use some epoxy)


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## silence dogood (Dec 5, 2020)

Do you have a wiring diagram of your lathe?  By adding to the circuit a diode(might take two diodes) in series with the lamp may do the trick.  That way you can use a 28v bulb. Just a thought.


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## RJSakowski (Dec 5, 2020)

If the bulb is powered by a.c, a diode will cut the wattage by almost half.  This should provide virtually eternal life.  If it is d.c. powered addition of a series resistor will extend the life.  In both case, brightness will be cut.


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## silence dogood (Dec 5, 2020)

RJ, you are correct on losing brightness.  Since it is a witness light, it may be okay. However,  I'm wondering why 30 volts?   This is why I'd like to see a wiring diagram then we could get a much better idea on how to solve this problem.  It could be a dropping resistor which could have change in value.  In that case, replacing the resistor would solve the problem.


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## Tozguy (Dec 5, 2020)

I do not have a wiring diagram for my lathe. However the Grizzly G4003 wiring is very similar to mine as far as I can tell. But there are no specs for the indicator lamp in Grizzly literature. 

What has been your experience with the power indicator light on your lathe? What voltage is used and how long does it last?

Since the 30 volt OEM bulb burnt out maybe I will try a higher voltage bulb just out of curiosity before moving on to one of your suggestions.

Stay tuned, I will need someone to hold my hand if I start messing with wiring and resistors.


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## silence dogood (Dec 5, 2020)

My lathe does not have an indicator lamp.  My mill has a LED that is a bit on the wimpy side for brightness.  Both of my machines run on 110v.  On each machine I wired a separate box with a switch that the machine plugs into.  Lights (in this case LED) are wired into the box.  When I turn on the switch, power is sent to the machine and the lights turn on illuminating  the machine.  You still have to turn on the machine separately by the switch on the machine itself.  If I want to work on the machine where the power should be unplugged, I still have lights shining on the machine. The other advantage is if I have shut the machine quickly, there is a off switch on both sides of the machine.  Looking up the Grizzly, I assume that your machine runs on 220.  It can be done but you may have to get a friend whose knows electricity to help you.  Else you can soldier in a LED with a resistor in the old bulb stem as shown by Markba, which is the easiest and a lot less messing around.


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## Tozguy (Dec 5, 2020)

The transformer in the control box of my lathe has 244 volts ac input and 27.2 volts ac output. Kinda makes me wonder why the 28 volt lamp burnt so quickly. Next I will remove the front cover to see how much space I have to work with.
I am going to look at changing the whole socket for an LED lamp that is commonly available.


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## RJSakowski (Dec 5, 2020)

I'm looking for a panel lamp for my lathe myself.  Here is one that came up   https://www.ebay.com/itm/1x-Green-L...102305&hash=item264627c9c8:g:XIUAAOSw-0xYN~Gj


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## silence dogood (Dec 5, 2020)

Is that all the transformer do, just run the indicator light?  Then you can just bypass the transformer and wire the  wire the lamp to the 220 as RJ  just came up with or do one leg of 220 which would give you 110 and use a 110 volt indicator.   I think that you will like the LED much better. The ones now are so much brighter.


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## Flyinfool (Dec 5, 2020)

Start with the obvious. grab a volt meter and see what voltage you actually have at the socket. also check and see if it is actually AC or DC, then we will know what we are working with. As mentioned above, the burnt bulbs may be a symptom of a different issue.


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## Tozguy (Dec 5, 2020)

Thanks RJ, thats great, looks like it will run direct on 240v.
s.d., I don't know if the transformer only supplies the indicator light.....it would surprise me if it was not also used for the switches and relays.
flyin, have already checked, its 27.2vac.


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## Tozguy (Dec 6, 2020)

Flyinfool said:


> the burnt bulbs may be a symptom of a different issue.


Something has dawned on me this morning, the transformer seems to have different input possibilities if I interpret the label correctly. 



My line voltage is 244 vac. but it is connected to the 220 vac terminals (20,21) of the transformer. Seems to me that this would explain why the output is 27.2 vac.instead of 24 vac. If the line is changed to the 240 volt input terminals (20,22) would that not drop the output to the specified level and hopefully be easier on indicator bulb life.

Please let me know if this makes sense before I go ahead and f$$$ something up. This is a view of the box before I turn it into a black charred mess.


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## SLK001 (Dec 6, 2020)

Tozguy said:


> My line voltage is 244 vac. but it is connected to the 220 vac terminals (20,21) of the transformer. Seems to me that this would explain why the output is 27.2 vac.instead of 24 vac. If the line is changed to the 240 volt input terminals (20,22) would that not drop the output to the specified level and hopefully be easier on indicator bulb life.
> 
> Please let me know if this makes sense before I go ahead and f$$$ something up. This is a view of the box before I turn it into a black charred mess.



Yes, it appears that your transformer isn't properly set up.  Change the inputs to the 240V position and your output voltage should return to normal and your burned out bulbs should be a thing of the past.


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## markba633csi (Dec 6, 2020)

There you go!
-M


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## middle.road (Dec 6, 2020)

I need one also for the 1440.
Time to grab another cup of coffee and read through this again - slowly.


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## Tozguy (Dec 6, 2020)

markba633csi said:


> There you go!
> -M



You betcha, piece of cake. And I didn't have to call the fire department.
After switching the wire from the 220v input terminal (#21) to the 240v terminal (#22) the output voltage went from 27 to 24v. Put the last 28v bulb I had in the socket and it is plenty bright. Now we just have to see how long it lasts.

Dan, if I can do this then anybody can. But its a good excuse for another cuppa.

Much appreciate everyone's help.


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## markba633csi (Dec 7, 2020)

Bulb should last MUCH longer- it's a non-linear curve,  a slight change in voltage makes a big difference in bulb life


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## mksj (Dec 8, 2020)

Just switch to a 24V LED indicator bulb, should last much longer.


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## hman (Dec 8, 2020)

See posts #4 and #7.


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## Tozguy (Dec 8, 2020)

Now I'm sure that the incandescent bulb will last, cause I bought four spare 28v bulbs to have on hand just in case it does not. Usually when I buy spares of anything they are never needed. 

Seriously, since my lathe is typical of many 'hobby' lathes (ex. G4003 and G0750) where the default connection to the transformer at the factory seems to be 220v, should the installation instructions not mention something about this (or did I miss something).


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## Flyinfool (Dec 8, 2020)

220 is very common, 240 is much less common. the machines will ship set up for the majority of typical customers. I do agree that the mannual should make mention of this somewhere as it IS a saleable feature, I guess many machines do not have the transformer taps for different input voltages.


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## mksj (Dec 8, 2020)

You have not indicated the base only the bulb, I am assuming it is a BA9S. LED bulbs work over a range of voltages and also different bulb configurations, including flat with the base. This one is specified as 24-18V AC/DC, also on eBay but typically questionable quality. As far as transformers, the asian ones often have a fixed tap or two taps on the input for say 220 or 240VAC, the default is setup for 220V. In your case the 24VAC was way high, although the transformer output will vary with load. The other issue is there is a wide variation in AC line voltages and they have cheeped up higher over the years and there can be more voltage swings. Ironically most smaller Asian machine come configured as yours with a 24VAC, and I really have seen bulb failure issue on the power light. On system I build, everything is LED indicators.





						Eiko - LED-24-BA9S-W - Miniature Bayonet Base LED Light Bulb, White (Replaces 24MB, 28MB, 313, 757, 1818, 1819, 1820, 1829, 1843, 1864, 1873 Light Bulbs) - Light Bulbs - Amazon.com
					

Eiko - LED-24-BA9S-W - Miniature Bayonet Base LED Light Bulb, White (Replaces 24MB, 28MB, 313, 757, 1818, 1819, 1820, 1829, 1843, 1864, 1873 Light Bulbs) - Light Bulbs - Amazon.com



					www.amazon.com


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## Tozguy (Dec 8, 2020)

The base measures .355'' in diameter so it must be a BA9S base.

Mark, does the transformer supply 24vac for other components (and not just the power indicator lamp)? The question has already been mentioned above but not answered yet.

One of the wiring diagrams I saw showed taps for 220, 230 and 240 volts which leads me to think that there might be a good reason to understand what this is all about. 

Some of the first automotive LEDs I have used did not last long and I have wondered why ever since.


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## SLK001 (Dec 8, 2020)

Tozguy said:


> Mark, does the transformer supply 24vac for other components (and not just the power indicator lamp)? The question has already been mentioned above but not answered yet.



It probably powers a control board, but the AC is rectified, then regulated to a set voltage.  A little over on this input won't hurt the control board at all.



Tozguy said:


> Some of the first automotive LEDs I have used did not last long and I have wondered why ever since.



The LEDs didn't last long because there were too few in the package and the ones that were there were over driven.  It's like having to run a 100 HP engine at 150% output for its entire life - which will be short.


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## mksj (Dec 8, 2020)

The AC is not rectified, the contactors are AC and will not run off of DC. Low voltage 24VAC is used for the control system, power to the front panel and spindle switch that then activates the contactors. The 24VAC voltage will fluctuate based on the load, contactors closed will draw more current. I am assuming KA is the main power contactor, KM1 and KM2 are the motor run in the respective direction. Transformers do not give a fixed output, their unloaded voltage can be much higher than loaded, varies by design and also the VA of the transformer. As far as how long LED last, there is a big difference in the quality and the design of the LED's and also if there are multiple LEDs or just one. With multiple LEDs in one lamp, you often see a cascade effect, one fails and then the remainder draw more current, and then the next until they all burn out. Ironically when I buy say a Philips brand LED lamp, I have yet to have one fail, the cheaper brands, in particular the junk on eBay often fail much sooner. I have also seen similar issues with the incandescent indicator bulbs, I often will source NOS like GE and they function correctly. I have measured the current, the newer lamps draw more current and shine brighter, and do not last. Reason why I mentioned just going with a decent brand LED indicator light after all the headaches you have had.

The transformer looks like it is around 63VA so around 2.6A, but is fused for 1A (FU3).


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## Tozguy (Dec 9, 2020)

Thanks for the explanations. If I understand correctly the system is not all that sensitive to normal voltage fluctuation. The change I made to the transformer input, that likely improves the life span of the indicator lamp, would not create problems elsewhere in the system. By lowering the output voltage from 27vac to 24vac, current draw might increase proportionally but it should still be within the limits of the 24v fuse.

 I did not realize that there are fuses in the system. Are these like breakers and can be reset or would they need to be replaced if they burn?


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## mksj (Dec 9, 2020)

Your system is designed to operate at 24V AC, not the higher voltage. Cnntactors operate at a specified voltage but will operate over +/- voltage range. They will probably operate from 20-28V AC (+20%/-10%), but depends on the contactor/relay and coil. Too low a voltage and the contacts may not fully close or chatter, too high (or too low) may cause premature failure. You have three fuses (not breakers), most likely FU1 and FU2 are each leg of the 120VAC going to the transformer, and as mentioned FU3 is one leg of the 24VAC output (only one side needs to be fused). These are fuses, the fuse holder typically swing out or pull out and you would need to use a fuse of the same style an amperage (1A). Should not need to replace the fuses unless there was a wiring short/overload.


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