Another useful thing I have always used for aquariums is a titanium grounding rod. This will protect the fish and everyone from any unwanted current flowing in the pond from any equipment that is not in good condition. But since most ponds use a liner one has to be very careful that the location of this grounding rod does not puncture the liner. This has save my live a few times where I was doing aquarium maintenance. Specially useful if one is using a submerged pump.
ELECTRICAL CONSIDERATIONS -- 2
- Thread starter Mmathis
- Start date
If an electrician suggested a whole house GFI, first make sure you understood them correctly, and if true, find another electrician. If Uncle Ernie suggested it, hand him a beer and pat him on the head.
It would be against code to have a whole house GFI. Some devices like a washing machine or a refrigerator can trip GFIs which leads people to do unsafe things like run an extension cord to another outlet. Today those devices require their own circuit and cannot be GFI according to code I believe. I'm not sure if other outlets, like a bedroom can have a GFI, but I'd check code before doing it.
If you wanted to upgrade something you could consider adding Arc Fault Circuit Interrupter (AFCI) where allowed. These can help prevent fires.
Or maybe they were talking about whole house surge protector? Sounds good doesn't it. They're find, do offer some protection. But they only protect against surges coming into the house. A lighting strike that gets to a water pipe, to a ground wire, no protection. It's possible for the surge to go from the ground wire to the panel before getting to a computer, TV, whatever, but that's just luck. Sometimes appliances can cause surges too. So even with a whole house protector devices still have to be plugged directly into a surge protector for true protection. That makes a whole house protector less helpful than the name may sound. But then they're not expensive so worth consideration. I personally wouldn't. One more thing to go wrong, I like simple.
It would be against code to have a whole house GFI. Some devices like a washing machine or a refrigerator can trip GFIs which leads people to do unsafe things like run an extension cord to another outlet. Today those devices require their own circuit and cannot be GFI according to code I believe. I'm not sure if other outlets, like a bedroom can have a GFI, but I'd check code before doing it.
If you wanted to upgrade something you could consider adding Arc Fault Circuit Interrupter (AFCI) where allowed. These can help prevent fires.
Or maybe they were talking about whole house surge protector? Sounds good doesn't it. They're find, do offer some protection. But they only protect against surges coming into the house. A lighting strike that gets to a water pipe, to a ground wire, no protection. It's possible for the surge to go from the ground wire to the panel before getting to a computer, TV, whatever, but that's just luck. Sometimes appliances can cause surges too. So even with a whole house protector devices still have to be plugged directly into a surge protector for true protection. That makes a whole house protector less helpful than the name may sound. But then they're not expensive so worth consideration. I personally wouldn't. One more thing to go wrong, I like simple.
Jneg,
I am sure that you do not mean a "titanium" grounding rod. You mean copper, solid copper or maybe a slightly harder alloy of high percentage copper. But, not titanium. A 5/8" copper rod, at least eight feet long is usually about the norm for a grounding rod.
For all who read this, the main point here is accurate. If your pump shorts out internally for some unknown reason, the electrical current will be shunted to the ground rod instead of your body because the copper ground rod offers a much less resistive path to earth ground and that takes the electrical current away from you.
However, a grounding rod of this sort is not a fool proof solution. They won't always protect a person from electical shock. They are necessary and do their job very well, but they are not exactly intended for personal prtection.
Circuit breakers are meant to protect your refrigerator, outlets and your oven or water heater and your other electical devices from total burn-out or fire if something bad should occur, but circuit breakers won't trip fast enough to save your life. GFCI's are what you truly want as they shut the current off so very quickly when a problem is detected that your life and limb are spared. Grounding rods do nothing but shunt electical current to earth ground, but you cannot stand in a pool of water and rely upon a ground rod to protect you. It doesn't work quite that nicely.
Gordy
I agree with you on this subject, I think that some folk are confusing whole house surge protectors with the operation of a GFCI. Hey, that is understandable, not everyone knows all about electrical systems and such. They don't work with this stuff daily and it isn't suprising that they have misconceptions in certain areas and on certain topics.
But, as long as they understand that if they don't understand it, that they shouldn't touch it, then they are safe.
Hire someone to do the things that you are not familiar with. Always play it safe! "When in doubt. get the hell out".
Gordy
Here is a link to a GFI Circuit Breaker from GE:
http://www.geindustrial.com/cwc/Dispatcher?REQUEST=PRODUCTS&famid=8&catid=36&id=cb-qgfci
You are right on some of the things you are saying but the circuit breakers are not for protecting equipment they are there just to prevent fires. You are correct in saying that circuit breakers are not there to protect people. No, I mean a Titanium probe one that goes directly into the water. All houses use a grounding rod like the one you describe but I'm not suggesting that type of grounding even though it could be helpful but not necessary. Besides if you install another grounding rod (copper one) you would have to bond it to the house one to only have one ground reference or else you risk causing lots of trouble. This is what I mean, maybe I used the wrong wording, so sorry for the confusion.
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=3946
No knowledge is safe. Solid knowledge if fairly safe (I have a rule, if I know I'm right, I'm probably wrong and I'd better double check). A little bit of knowledge will screw you every time.
Grounding a pond or tank does have a benefit. With a plastic liner most ponds are not grounded. A short in a pump can just sit there until you reach into the water and you get to be the ground. Hand to foot path could go right across your heart. So even if you're a poor ground, standing on dry soil or concrete in sneakers, you could still be in trouble. Hence the GFI. If the pond is grounded a short should trip any breaker because the current would flow fast.
jneg, not sure why you provided a link to a GFI breaker? That doesn't protect a whole house, just a single circuit, like to the bathroom outlets.
Grounding rods to not have to be tied into the house. Their only purpose is to give shorts a good path so all of sudden the current shoots way up which any breaker can detect.
Grounding rods to not have to be tied into the house. Their only purpose is to give shorts a good path so all of sudden the current shoots way up which any breaker can detect.
Ciruit breakers ARE designed to protect equipment.
If you have a motor that drives a shaft to turn a pump, and the pump mechanism is locked up or the bearings are seized, one of two things may happen. The motor may have an internally provided thermal overload protection circuit which will "trip" if the motor becomes overheated due to excessive load, but this usually comes into play when there is a heavy load on the output shaft of the motor, not so much if it is completely seized.
When it is seized, the motor will draw excessive current because it cannot build up rotary speed to click off its starter circuit. Starter circuits usually allow for a short period of high in rush current until the motor's rotor acquires sufficient speed, then a centrifugal switch disengages the start circuit and switches over to the run mode circuit. A properly designed circuit breaker system will trip out if the motor remains in the start mode for too long. Thus, it protects the windings of the motor from overheating and breaking down the winding insulation, which could cause in the long term, a short and eventually a fire. So, a CB's first duty is to protect the equipment from such overloads. Fire suppression is just a sort of byproduct and second stage protection. Protecting the motor or the device, whatever it may be from damage, hopefully protects you from fire. But the latter is an indirect operation and a secondary advantage or perk.
In quick, a motor failure could result in a fire if the internal thermal overload does not engage and cut power first. If that fails, then the circuit breaker takes over and if it protects the motor from failure, a fire hopefully will not occur. The motor may just become quite HOT.
Gordy
If you have a motor that drives a shaft to turn a pump, and the pump mechanism is locked up or the bearings are seized, one of two things may happen. The motor may have an internally provided thermal overload protection circuit which will "trip" if the motor becomes overheated due to excessive load, but this usually comes into play when there is a heavy load on the output shaft of the motor, not so much if it is completely seized.
When it is seized, the motor will draw excessive current because it cannot build up rotary speed to click off its starter circuit. Starter circuits usually allow for a short period of high in rush current until the motor's rotor acquires sufficient speed, then a centrifugal switch disengages the start circuit and switches over to the run mode circuit. A properly designed circuit breaker system will trip out if the motor remains in the start mode for too long. Thus, it protects the windings of the motor from overheating and breaking down the winding insulation, which could cause in the long term, a short and eventually a fire. So, a CB's first duty is to protect the equipment from such overloads. Fire suppression is just a sort of byproduct and second stage protection. Protecting the motor or the device, whatever it may be from damage, hopefully protects you from fire. But the latter is an indirect operation and a secondary advantage or perk.
In quick, a motor failure could result in a fire if the internal thermal overload does not engage and cut power first. If that fails, then the circuit breaker takes over and if it protects the motor from failure, a fire hopefully will not occur. The motor may just become quite HOT.
Gordy
The purpose of grounding rods are two fold, at least.
One, to direct a lightning strike directly to ground OUTSIDE of the home. Provide the lightning bolt with the least resistant path to ground, rather than having it make its way through your internal house wiring to locate a good ground connection. If the lightning can make its way into the home, it can ignite the would and other materials along the way and start a fire almost instantaneously.
Second, if you lose the neutral leg from your electrical circuit, the ground rod will hopefully supply a path of least resistance for the hot line power if a short or some other failure should occur. Normally, that current or electrical power would return to the source via the neutral leg of the circuit. However, if the neutral leg is somehow broken and the hot lead contacts the metal frame of an appliance, the frame of the appliance shoud be connected to the ground rod and shunt the current through that pathway, rather than through anyone who happens to touch the equipment.
It is meant to be a backup safety feature.
Gordy
One, to direct a lightning strike directly to ground OUTSIDE of the home. Provide the lightning bolt with the least resistant path to ground, rather than having it make its way through your internal house wiring to locate a good ground connection. If the lightning can make its way into the home, it can ignite the would and other materials along the way and start a fire almost instantaneously.
Second, if you lose the neutral leg from your electrical circuit, the ground rod will hopefully supply a path of least resistance for the hot line power if a short or some other failure should occur. Normally, that current or electrical power would return to the source via the neutral leg of the circuit. However, if the neutral leg is somehow broken and the hot lead contacts the metal frame of an appliance, the frame of the appliance shoud be connected to the ground rod and shunt the current through that pathway, rather than through anyone who happens to touch the equipment.
It is meant to be a backup safety feature.
Gordy
GFCIs are very sensitive circuit breakers. But they do not operate on the same principle. Circuit breakers detect a current overload and trip to cut the circuit off.
GFCIs monitor the outgoing and return current and if even a very small imbalance of current is detected, it cuts the circuit off immediately. This action hopefully protects people from life threatening current shocks. i.e. if you grabbed a hot wire and began to get electrocuted, the GFCI breaker would sense that some of the current going into that circuit is not returning (because it is going through you to ground). It therefore knows that there is a fault and opens the circuit to shut off the power. It does it at such a low current value and so fast the you might not even realize that you had been shocked, If you do, it would be over so fast that it would nto harm you.
Gordy
GFCIs monitor the outgoing and return current and if even a very small imbalance of current is detected, it cuts the circuit off immediately. This action hopefully protects people from life threatening current shocks. i.e. if you grabbed a hot wire and began to get electrocuted, the GFCI breaker would sense that some of the current going into that circuit is not returning (because it is going through you to ground). It therefore knows that there is a fault and opens the circuit to shut off the power. It does it at such a low current value and so fast the you might not even realize that you had been shocked, If you do, it would be over so fast that it would nto harm you.
Gordy
Yes a breaker protects equipment, but to say they were designed for that purpose is an interesting opinion.
If we're now talking about any type of grounding rod I should imagine there are many uses. I was referring to the context of the thread.
If we're now talking about any type of grounding rod I should imagine there are many uses. I was referring to the context of the thread.
I did take quite a large margin of license to state that this was the absolute design principle for CBs. It is one of a CBs primary duties, if not their main purpose, but to say that they were originally designed for that alone is stretching it. I always use the same analogy, however, because when we have safety meetings at work, some people have the misconception that general purpose CBs will protect them from electrocution. This is certainly not true. A person would be dead long before that CB tripped.
No offense to Jneg, but I didn't quite understand how he was utlizing such a grounding rod in the pond application. I know of only one approved type of grounding rod application. He may have just used some wording that elluded me, but I really got thrown off by the titanium rod. It truly should be copper or at least some alloy of copper. Maybe the rules in Peurto Rico are different, but we have to use copper rods here.
Jneg is very correct when it comes to bonding the ground rod to the house grounding system. Grounding electrical circuits with multiple grounds can be a very complex notion and you can end up with what is called a "ground loop" and create all sorts of trouble. I can tell by just how he phrased the statement that he is aware of that troublesome concern. Grounding is almost an industry in itself because it can act so strange if not done correctly.
Gordy
Titanium is used because the rod goes into the aquarium, not the ground. Copper in the aquarium isn't considered a good idea.
By code ground rods can be made of anything that conducts electric. The result just has to be 25 ohms or less. Code allows multiple grounding rods.
Ground loop has to do with the difference between "earth grounding" and "equipment grounding". Has nothing to do with multiple grounding rods.
By code ground rods can be made of anything that conducts electric. The result just has to be 25 ohms or less. Code allows multiple grounding rods.
Ground loop has to do with the difference between "earth grounding" and "equipment grounding". Has nothing to do with multiple grounding rods.
Yeah, stretching it. That's an interesting way to spin it. Especially since the circuit breaker was invented before electrical equipment was used much and was crude. The patent said its purpose was to protect lighting circuit wiring from accidental short-circuits and overloads. You'll have to forgive me, I tend to believe the inventor. A habit I picked up awhile back after getting into internet forums.
OK, I can bite on the idea of not using copper in an aquarium or a pond in that regard. But, does anyone really think that it is safe? Regardless if it were copper or titanium or silver or even gold for that matter? Sorry, I just have this cartoonish vision like the "ZAP" X-Ray view of all the bones in the body with the outline of the body in black shading.
The problem here is not the fact of multiple grounding rods, it is the notion of difference in the potential between the two. This is due most often to the bonding between them and not because there is any difference in the ground connection of the rod itself. I have chased many grounding problems down in the past and they are extremely illusive. They are not always what you think they would be caused from and they can create all manners of weird behavior in electronic or electrical circuits. It is really beyon the scope of most electricians and even electronic engineers. I absolutely don't know a great deal about it because to me, it seems like chasing ghosts.
Instead of measuring amperes, volts and ohms, you need to measure microamps, microvolts and siemens. You wouldn't think they would have any effect at all, but they can and do.
But Waterbug, isn't electrical wiring, switches and lighting also considered to be "electrical equipment"? Just because we have advanced our electrical equipment over the years to include motors and computers and televisions, that does not make the electrical equipment of their day, way back then, any less unique or immune to the same problems and defects.
None of us are incorrect here, it is just the manner in which we are looking at it that is different. The main theme or purpose is the same irregardless and that is to shut the circuit OFF if a fault exists in order to protect either that one faulty device and/or the rest of the system from total failure. It doesn't matter if it is a motor or a stove or a computer or just a wire and a switch and a porch lamp.
OK, you can put in the last word and we will tie this one up so that we don't detract from the original subject any further.
I really enjoyed this discussion with you, Waterbug! I am from a semi-large family and we used to all get together and talk like this. Have some coffee or a beer around the kitchen table and talk all day or night. Now, my brothers and sister are getting old and have slowed down, have their own grown up families to contend with and I don't have anyone to discuss "shop" with very often. I miss that. So, I am not arguing with you, I am just very fond of the opportunity to discuss the subject with you. I have to just say thank you for this one.
Gordy
Why wouldn't it be safe? They're UL listed. They think they're safe. Good enough for me.
Yes. That's why a ground rod has nothing to do with a ground loop. It's purely an issue in the connection between the "earth grounding" and "equipment grounding".
Oh you magnificent spin doctor....Yes, you are absolutely 100% correct. Ever think of being a campaign manager? I guess it would also be true to say circuit breakers were invented to protect magazines. Because if the house burned down the magazines would be destroyed. Perfect logic, I guess.
I somehow doubt that. I'd bet serious cash I've made at least several mistakes. I'm more into the learning end of things than the everyone is always right type deal. I like my mistakes to be pointed out. I enjoyed the discussion as well.