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grease or NO OX? Or will grease suffice for NO-OX
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Whole house weirdness...this is crazy!
- Thread starter GunsOfNavarone
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- Feb 13, 2017
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"No-Ox" is one of the many brands of interface greases available. When I stated "grease", that is what I was refering to. It is specificaly for electrical connections and has no lubricity as such. DO NOT use regular lubricating grease, wheel bearing grease, for electrical connections. The grease is formulated specifically for aluminium to copper connections and should be available at most any hardware store that carries electrical devices.
Power companys have used aluminium for transmission lines and service drops since the mid '60s. AL came into common use for residental internal wiring a few years later as copper got even more expensive. There was a moritorium placed in the late '70s-early 80s on aluminium wiring for "branch circuits". (it became 'illegal' for new work) However, it was still allowed for entrance and heavy 240 volt (range, dryer, installed AC) loads. In recent times, I have heard of a resurgance in its' use for internal wiring. I am, and always have been, using copper wiring. Period, no 'just this once'. I have lost several of jobs when I first came out of the service for such a stance. That's why I went industrial. . .
Today, the are many (most?) connectors (plugs) marked "AL/CU" or "CU/AL" that can accomodate aluminium wiring. Or so I hear, I stick with copper Romex or UF or conduit myself, so it's a non-issue. Power suppliers use such connectors even when connecting AL to AL. The crimps have that little extra 'something' that makes for better connections.
The original concern is that brass is a compound (alloy) of copper and zinc (brass) or tin. (bronze) Aluminium has a different coefficient of expansion than copper, much higher. When, for example, a receptical is loaded heavily, the AL expands more than the brass screws it is landed under. As the load is removed, the AL shrinks to its' original size but the brass doesn't. This leaves a gap of sorts. Over time, such a gap corrodes, increasing resistance in the junction and generating heat. The heat exacerbates the problem, causing the joint to further expand. Essentially positive feedback, the problem getting worse each time. Such a problem was eventually traced as the root cause of many fires, some catastrophic. That is why it was outlawed for new work.
Modern connectors can accomodate such expansion, or so I am told. I'll just stick with copper for what little I do these days.
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Power companys have used aluminium for transmission lines and service drops since the mid '60s. AL came into common use for residental internal wiring a few years later as copper got even more expensive. There was a moritorium placed in the late '70s-early 80s on aluminium wiring for "branch circuits". (it became 'illegal' for new work) However, it was still allowed for entrance and heavy 240 volt (range, dryer, installed AC) loads. In recent times, I have heard of a resurgance in its' use for internal wiring. I am, and always have been, using copper wiring. Period, no 'just this once'. I have lost several of jobs when I first came out of the service for such a stance. That's why I went industrial. . .
Today, the are many (most?) connectors (plugs) marked "AL/CU" or "CU/AL" that can accomodate aluminium wiring. Or so I hear, I stick with copper Romex or UF or conduit myself, so it's a non-issue. Power suppliers use such connectors even when connecting AL to AL. The crimps have that little extra 'something' that makes for better connections.
The original concern is that brass is a compound (alloy) of copper and zinc (brass) or tin. (bronze) Aluminium has a different coefficient of expansion than copper, much higher. When, for example, a receptical is loaded heavily, the AL expands more than the brass screws it is landed under. As the load is removed, the AL shrinks to its' original size but the brass doesn't. This leaves a gap of sorts. Over time, such a gap corrodes, increasing resistance in the junction and generating heat. The heat exacerbates the problem, causing the joint to further expand. Essentially positive feedback, the problem getting worse each time. Such a problem was eventually traced as the root cause of many fires, some catastrophic. That is why it was outlawed for new work.
Modern connectors can accomodate such expansion, or so I am told. I'll just stick with copper for what little I do these days.
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- Feb 13, 2017
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Aluminium wire is not as conductive as copper. For most applications where AL is used, the wire must be "derated" one wire size. That is to say that when a 15 amp circuit is in use, AWG 14 copper wire will carry the load. If aluminium is used, the wire size must be increased to AWG 12 with the same 15A fuse or circuit breaker.
This "rule of thumb" applies from AWG 14 copper up to at least 000-3/0 copper which becomes AWG 12 to 0000-4/0 AL. That being a service drop capable of handling 200 amps at 240 volts. There are many other factors relating to entrance cables. The AWG 4/0 I am referring to is type SER, a flat cable of two current carrying conductors and a slightly smaller wire wrapped around the other two in a spiral inside a jacket. If the entrance cable from the meter to the splice is a cable, it likely is SER. That type of cable is available as copper as well. It is available from AWG 6 and larger, maybe smaller. I never needed any so don't know. Type SER is used for branch cables of heavy 240 volt loads, although AL is commonly in use too.
Aluminium is/was used widely for industrial applications as well. When heavier wire is needed, the cost of AL far outweighs the cost of smaller copper. The installations I have touched on here are for residential uses, mostly because more readers can look at their "house power" boxes or entrances and recognize what they see.
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This "rule of thumb" applies from AWG 14 copper up to at least 000-3/0 copper which becomes AWG 12 to 0000-4/0 AL. That being a service drop capable of handling 200 amps at 240 volts. There are many other factors relating to entrance cables. The AWG 4/0 I am referring to is type SER, a flat cable of two current carrying conductors and a slightly smaller wire wrapped around the other two in a spiral inside a jacket. If the entrance cable from the meter to the splice is a cable, it likely is SER. That type of cable is available as copper as well. It is available from AWG 6 and larger, maybe smaller. I never needed any so don't know. Type SER is used for branch cables of heavy 240 volt loads, although AL is commonly in use too.
Aluminium is/was used widely for industrial applications as well. When heavier wire is needed, the cost of AL far outweighs the cost of smaller copper. The installations I have touched on here are for residential uses, mostly because more readers can look at their "house power" boxes or entrances and recognize what they see.
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So, if I wanted to clean up my connections in my breaker box and put dielectric grease in there as well, what is the safe technique for doing this?
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@Bi11Hudson may have more/better advice, but IF you have a service disconnect switch between your meter and your breaker box, then shutting that off would allow you to safely work on your breaker box. Standard safety warning would be to use a voltmeter to check that it is indeed off at the main feed into the breaker box. If the breaker box is connected directly to the meter without a separate disconnect switch, then I would advise having an electrician look at it. Even if you throw the main breaker at the top of a breaker box, the lines coming in from the meter would still be hot, and pulling wires loose around those hot terminals is hazardous.
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The "safest" method to do so is simply remove the meter. If you called an electrician, that is what he would do. That kills everything from the bottom of the meter can out. However, there are a few problems even with that. Particularly with the power supplier. If you are in GOOD STANDING with the power company, having paid your bill regularly for several years, AND code authorities are slack AND the power lineman is not an a$$, AND you have not cut the seal on the box for a while, you MIGHT get by with it. I have done so several times, but have lived here 40 plus plus years, have a rather "cum se, cum sa" power supplier, and did the original rewire under a permit myself. If you have a disconnect switch, common in some locations, just pull the switch.
What it comes down to is that when you have met all of the above, plus a few others that depend on location, and cut the seal on the meter can, the next time a meter reader or lineman comes by, the missing seal will be noted and possibly reported. A second seal, of a different color will be placed and a closer watch kept. If that seal is cut within a year or two, you will get a padlock. If that is cut, all I can say is "Good Luck" in the forthcoming court case.
Under any other conditions, the inside of the breaker box will be hot. There will be some protective panels and the general arrangement of hot wires will protect against contact, shocks, but are in no way absolute. Consider anything behind the panel as a shock hazard. A breaker can be turned off and removed from the panel. Once it is removed, it will be considered safe to touch. Unless there is a "cross feed" or other shenanigans from an inept modification. So double check after the breaker is powered off that there is no power from the terminal to ground. Only then, snap the breaker out of the panel. You are now free to do whatever is required to the breaker terminal in hand.
To apply the grease, loosen the screw and remove the wire. Squirt a little grease and and stir it around. Squirt a little on the bare wire and coat the exposed conductor. Avoid a glob that would transfer, the grease is conductive. Reinsert the wire under the terminal clamp, specificly how will depend on the breaker brand. Tighten well but not overstressed. The expression of "two snaps and a grunt" will be too tight. Replace the breaker in the panel, watching how the wire is dressed. If you encounter a double pole or "piggy back" be sure to do one wire at a time so the connections are not crossed up. Once you have done all except the mains at the top (usually), replace the panel. Do not do the mains, period. Call a licensed electrician to do them, hot or not. Remember to grease the white wires where they are located on the "neutral bus". Keep in mind that these wires will likely be hot with the power on. If the panel is not dead, simply tighten them. Do not overtighten them, same as the breaker screws.
If this sounds complicated and dangerous, that's because it is. That is one (of many) reason electricians charge such preposterous prices. Your asking how to do it leads me to think you are not competant enough to do the job. I am not saying that you are incompetant in general, but electricity is a very complex and detailed subject requiring years of apprenticeship to wire a house. Industrial knowledge and troubleshooting is even more so. I have well over 50 years in the field, and only know some aspects. The "code" is for people that know what they are doing to start with. If you want to consider this as a disclaimer, please feel free to do so. I was mastered (Fla, ~'74) for a while but now grossly out of date.
Bi11 Hudson
Master Artificer (Ret)
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With my rural co-op, if I or an electrician cut the meter seal, I'd call the power company immediately and tell them it was pulled for work on the main panel rather than waiting for them to discover it. Generally if reported they don't make a fuss, they just send someone out to replace the seal. This is especially true with more and more meters being read remotely/over the wire. Your utility company/permitting/zoning may be different, but giving them a heads up is preferable to them discovering it, as a cut seal is their indication that someone has tampered with THEIR meter and might be stealing power.
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