Fireproof fluorescent tube ballast
- Thread starter Rogue5861
- Start date
Help Support Aussie Pythons & Snakes Forum:
- Status
B
Bluetongue1
Guest
I suspect you’ll find that the ballast does not get any hotter than say a 100W light globe or a 60W CHE – way too hot for the fingers but given space and air flow around it, not a fire hazard. Light globes in boxes made primarily of peg board used to heat snake cages before other heating devices were available.
Water with any solutes in it is the biggest danger in producing an electrical fault. Exposed wiring, even inside electrical connectors, if accessible to dust can be a problem. In particularly humid weather, atmospheric humidity can condense around the dust particles. If their is a continuous layer of water between different connections or something metal, then an electric current can flow if there are solutes in that water. Salt from air that has travelled over oceans is not insignificant over time. Rainfall annually deposits from 20 kg/ha inland up to 300 kg/ha in coastal areas.
The earth wire is so called because it runs from an electrical appliance directly into the earth. Where copper water pipes are used, the earth wire is often attached where they go into the ground. If plastic pipes are used, then the earth is usually attached to a star picket driven halfway or more into the ground. The earth is like a big sink that will readily absorb free electrons without building up a charge or any resistance to more. When a lightening bolt hits the earth, there is no charge remaining at the point of entry, despite the massive electrical charge involved.
Electricity takes the path of least resistance. So if it had a choice between 3 units of resistance and 1 unit, ¼ of the current would go the 3 unit path and ¾ of it the 1 unit path. A faulty electrical device allows electricity to flow to its casing. If you touch the casing, electricity will flow through your body into the earth. An earth wire provides much less resistance than the human body and so more current will flow via the earth wire and less through you.
In a sentence: Earth wires take most of any leaking current directly to earth.
Blue
PS. You should also have an RCD = Residual Current Device. “Residual” in maths is the amount remaining when you take one number away from another i.e. the difference. An RCD measures the current going into a house and the current coming out. They should be equal. If there is a difference (a residual) it means current is leaking out of the electrical circuits within the house and all electrical power is immediately cut. The speed with which these work has saved many lives.
How’s that for a layman’s explanation Snowman? (apart from long-winded LOL)
Water with any solutes in it is the biggest danger in producing an electrical fault. Exposed wiring, even inside electrical connectors, if accessible to dust can be a problem. In particularly humid weather, atmospheric humidity can condense around the dust particles. If their is a continuous layer of water between different connections or something metal, then an electric current can flow if there are solutes in that water. Salt from air that has travelled over oceans is not insignificant over time. Rainfall annually deposits from 20 kg/ha inland up to 300 kg/ha in coastal areas.
The earth wire is so called because it runs from an electrical appliance directly into the earth. Where copper water pipes are used, the earth wire is often attached where they go into the ground. If plastic pipes are used, then the earth is usually attached to a star picket driven halfway or more into the ground. The earth is like a big sink that will readily absorb free electrons without building up a charge or any resistance to more. When a lightening bolt hits the earth, there is no charge remaining at the point of entry, despite the massive electrical charge involved.
Electricity takes the path of least resistance. So if it had a choice between 3 units of resistance and 1 unit, ¼ of the current would go the 3 unit path and ¾ of it the 1 unit path. A faulty electrical device allows electricity to flow to its casing. If you touch the casing, electricity will flow through your body into the earth. An earth wire provides much less resistance than the human body and so more current will flow via the earth wire and less through you.
In a sentence: Earth wires take most of any leaking current directly to earth.
Blue
PS. You should also have an RCD = Residual Current Device. “Residual” in maths is the amount remaining when you take one number away from another i.e. the difference. An RCD measures the current going into a house and the current coming out. They should be equal. If there is a difference (a residual) it means current is leaking out of the electrical circuits within the house and all electrical power is immediately cut. The speed with which these work has saved many lives.
How’s that for a layman’s explanation Snowman? (apart from long-winded LOL)
S
Snowman
Guest
Very good 
andynic07
Very Well-Known Member
Blue, you are mostly correct in what you are saying but in Queensland and possibly most other states all electrical installations are to have their own dedicated earth electrode and sometimes there can be a bond (equipotential) to the copper water pipes. The earth electrode and its position has a set of rules that determine it is suitable for purpose. The earth electrode is in place as a path for electricity to return to is source as all electricity will try and get back to its place of origin and this stake does not aid in the operation of an RCD but your explanation of of the RCD is very good. As another little fact to add to your repertoire is that when a power line falls to the ground mainly high voltage you can receive an electric shock without touching the wire, this is because of phenomenon called step potential and it is due to the poor connection (high resistance) to the general mass of earth. At the point of contact there will be full line voltage and it will not reach 0 volts until a certain distance away (depending on the voltage and ground material) , as you walk towards the wire there will be a voltage difference from one foot to another providing a possible second path for electrons to flow.
S
Snowman
Guest
In the cbd of Melbourne I've been told an urban legend that if you drive two earth electrodes into the ground 50m apart you can get a light globe to glow. Something to do with leaked current and difference in potential. Can't recall the full specifics, but an electrical inspector I used to work with swore it was true.
andynic07
Very Well-Known Member
Sounds like an urban myth to me, the mass of ground is said to have zero resistance and it is the connection to earth that is of high resistance. I know practically that it can't be zero and different materials have different resistivity but generally for calculation they call it zero.
S
Snowman
Guest
That was my thinking too. But apparently the different depths of earth stakes creates a potential and a wire and light between them is less resistance. We all had money bet on the outcome. But no one ever did the experiment.
andynic07
Very Well-Known Member
I will have to try and get my mind around that one a bit more. Once the NBN is built we could try it between WA and Queensland, as long as it is the same across Australia as here(fibre inside and aluminium outside).
Rogue5861
Very Well-Known Member
Spoke to a mate from work, worked an electrical apprentice (drop out yr 4 as company went under). He said as an unqualified electrician he could still give advice in what im doing.
He suggested that i crimp the earth wire (from wall plug) and screw it into the ballast mounting plate/casing, said this would be a sufficient way of grounding it. Im guessing no one qualified can answer this question but i will ask my sparky and see what he says.
Some of you guys really know your fields, its good to see that you are willing to provide direction for us trying to wrap our heads around it.
Rick
He suggested that i crimp the earth wire (from wall plug) and screw it into the ballast mounting plate/casing, said this would be a sufficient way of grounding it. Im guessing no one qualified can answer this question but i will ask my sparky and see what he says.
Some of you guys really know your fields, its good to see that you are willing to provide direction for us trying to wrap our heads around it.
Rick
andynic07
Very Well-Known Member
Anyone even those without any training can give advice but whether that advice is sound or not is another story. You are best to just leave it for the sparky that you intend on getting since he will be there anyway.
Rogue5861
Very Well-Known Member
Apparently a qualifed sparky cant give exact answers on whether it is right or wrong, ethics maybe?
Mounted ballasts and put everything in the right spots, just need to mount heat lamps and im all set ready for him to finish off.
Temps of the ballast was around 70c, about 150f so i was just reading wrong temp on my gun. I dont think this should be a drama but will insert a tile between ballasts and melamine just incase.
Thanks all for the help, next time i will know.
Rick
Rogue5861
Very Well-Known Member
Yep, thats what im saying. It really is crazy the amount of people that understimate electricity and end up with a fire or get shocked.
Rick
Skeptic
Well-Known Member
I've electrocuted myself twice through DIY. One time I was literally hanging onto two purlins in an industrial shed about 6 metres off the ground. Thank god for circuit breakers You're always better off leaving it to the professionals when it comes to stuff that can kill you.
You're always better off leaving it to the professionals when it comes to stuff that can kill you.
B
Bluetongue1
Guest
Sorry but I consider that “mostly correct” is not an accurate appraisal. It was quite deliberate That I did not mention multiple earth electrodes or equipotential bonding or earthing networks etc. I could also have talked about the need for thermal throw out switches / fuses or the effects of different soles on footwear or the hazards of working in wet areas ect. I kept the example given purposely simple, and avoided use of technical terms where possible, to provide an overall uncomplicated explanation.
This is not correct. Take lightening for example. It originates in the atmosphere and can flow back into the atmosphere (cloud to cloud discharge) or into the earth (cloud to earth discharge). RWhat What I have previously said about an “electrical sink” can be found on the net and in texts
I do not know why you made this comment. I did not link the two, even though they are linked. An RCD is essentially an earth leakage circuit breaker that works by detecting the fault current.
Thanks for the info on Step Potential. I was aware of the danger of high voltages at a distance. I knew that current from downed high tension wire would travel some distance due to the very high emf. What I did not understand was why it entered the body. With the rate of voltage drop-off and the high voltages involved, the potential difference involved in the distance of one step could result in a fatal level of voltage. Thanks again for that.
Blue
Rogue5861
Very Well-Known Member
Please check title of thread and direct mod to the exact post you are refering to, no one has suggesting diy wiring at all and it was all installed by a licenced electrician.
Thread can be closed/deleted as i have my answer, ballasts are not hot enough to cause a fire (70c).
Rick
Last edited by a moderator:
J-A-X
Very Well-Known Member
The only reason this is still going is to help educate people of the potential dangers of Electrical wiring gone wrong. No where does it state that the OP should be doing it himself and the OP has said that a qualified electrician will be doing the wiring so we can only hope they stick to that statement.
Snowman and AndyNic are qualified. So their statements stay.
@ Spongebob.
Your public comments against the moderation of the thread is in itself an infractable offence, but because you're trying to protect others I will not infract but just delete the post. Any objections should be submitted via a ticket to the support centre
Snowman and AndyNic are qualified. So their statements stay.
@ Spongebob.
Your public comments against the moderation of the thread is in itself an infractable offence, but because you're trying to protect others I will not infract but just delete the post. Any objections should be submitted via a ticket to the support centre
andynic07
Very Well-Known Member
Blue, I thought you did do a very good job in layman's terms but the particular sentence that I was trying to correct was "Where copper water pipes are used, the earth wire is often attached where they go into the ground. If plastic pipes are used, then the earth is usually attached to a star picket driven halfway or more into the ground" and the reason I tried to correct it was that to me this sentence suggests that it is the copper water pipe that is used for the primary earth electrode and if unavailable then a star picket is to be used? I can understand that you were possibly using a star picket to represent the earth electrode so people would visually get a good idea of what is trying to be achieved but my main objection was that whether a copper water pipe entering the ground is available or not an earth electrode must be present by law in Queensland and possibly other states. As for your point about lightning , this is static and acts quite similar but also quite differently to the generated electricity. With generated electricity ( and I know static is also generated and electricity) it will always try to get back to its source of supply, I will give you some examples that you can google that may show you this. Firstly in rural areas of Queensland they use a type of high voltage transmission system called S.W.E.R. and this stands for single wire earth return and it is exactly as it sounds , it uses a single wire out to a transformer and uses the earth as the return path. Secondly I will use our three wire high voltage system that we use in most other parts of Queensland, most of the power transformers at our substations (33KV to 11KV) will have a winding configuration called delta/star meaning the primary windings are connected in a delta style and the secondary windings are connected in a star style. What this means is the secondary windings will be given an earth reference and this is done so we can put a protection system into place to shut off supply if a wire falls down to earth. What this does is uses the earth to provide a path back to the transformer where it comes from and this current flow can then be measured and circuit breakers tripped. Without this reference to earth at the power transformer a wire would be able to fall to the ground and nothing happen.
B
Bluetongue1
Guest
The specific requirements in NSW, Vic and WA are not the same as those of Queensland. I don’t know about the rest as I got tired of looking. This statement comes from the Western Power website: “The earth wires from power points join to a main earth wire, which is attached to a metal pipe and/or special metal electrode (metal stake) driven into the ground.” Western Power: Earth wireshttp://www.westernpower.com.au/safety/Earth_Wires.html. Clearly there are difference requirements in different states, something that neither of us were aware of.
The earth electrode is in place as a path for electricity to return to is source as all electricity will try and get back to its place of origin. Our electricity originates from power stations above ground, not the earth. I don’t dispute that electricity will readily enter and leave the earth. It does because of the nature of the earth’s surface layer not because it is wants to return to its origins. I have yet to hear of rounded electricity entering the earth wires below power stations or even transformers. I understand that the current from the secondary coil in the step-down transformer can be effectively short-circuited by grounding it, thereby allowing work on power lines. The electricity does not return to coil, in which it was induced, not the earth. Being AC, current will flow in and out of the earth.
I believe our different perspectives are related to the language used to describe electricity. The notions of a closed “circuit” and a “return path” are a hangover from Edison and direct current days. We say that an earth wire provides a “return path”. What it really means is that electricity requires somewhere to flow or all current in the given wiring will stop. The earth’s surface layer is able to provide that “somewhere to flow” and can therefore “complete circuits”.
Blue
The earth electrode is in place as a path for electricity to return to is source as all electricity will try and get back to its place of origin. Our electricity originates from power stations above ground, not the earth. I don’t dispute that electricity will readily enter and leave the earth. It does because of the nature of the earth’s surface layer not because it is wants to return to its origins. I have yet to hear of rounded electricity entering the earth wires below power stations or even transformers. I understand that the current from the secondary coil in the step-down transformer can be effectively short-circuited by grounding it, thereby allowing work on power lines. The electricity does not return to coil, in which it was induced, not the earth. Being AC, current will flow in and out of the earth.
I believe our different perspectives are related to the language used to describe electricity. The notions of a closed “circuit” and a “return path” are a hangover from Edison and direct current days. We say that an earth wire provides a “return path”. What it really means is that electricity requires somewhere to flow or all current in the given wiring will stop. The earth’s surface layer is able to provide that “somewhere to flow” and can therefore “complete circuits”.
Blue
- Status
Similar threads
