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Post by c64 on Feb 6, 2016 16:26:46 GMT
if you upgrade to a heat pump, you are potentially losing efficiency, again. How so? A heat pump can give you up to 10 times more heat energy than just "burning" the electricity it consumes. In worst case it gives you almost the heat energy it consumes as electric energy. The net efficiency compared to a resistor heater is between 300% and 700% depending on your area and the kind of pump how it harvests its energy from outside. |
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Post by GTCGreg on Feb 6, 2016 16:30:28 GMT
Here, we only use white for neutral. Blue is either one phase of a three-phase circuit or, on a single phase circuit, it's usually a switched circuit such as a wall switch controlling a ceiling light or switched outlet for a floor or table lamp.
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Post by GTCGreg on Feb 6, 2016 16:40:06 GMT
A heat pump can give you up to 10 times more heat energy than just "burning" the electricity it consumes. In worst case it gives you almost the heat energy it consumes as electric energy. The net efficiency compared to a resistor heater is between 300% and 700% depending on your area and the kind of pump how it harvests its energy from outside. they usually don't rate them in efficiency though. They usually rate their COP (coefficient of performance). I don't know why, it's much more confusing that way. |
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Post by silverdragon on Feb 6, 2016 17:30:40 GMT
Erm, since when?...
Three phase, use phase one and two to get 480v, or 2&3 or 3&1, if you just use a single phase and the "Neutral" you only get 240v.
The way streets are set out, they send a single phase up street one, then two up street two, then three up three, then start again, this evens out the demand on all the phases.
The phases used to be red yellow blue, they are now Brown Black and Grey, which is dead useful in the dark for working out which is which isnt it?..
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Post by GTCGreg on Feb 6, 2016 17:39:49 GMT
Erm, since when?... Three phase, use phase one and two to get 480v, or 2&3 or 3&1, if you just use a single phase and the "Neutral" you only get 240v. The way streets are set out, they send a single phase up street one, then two up street two, then three up three, then start again, this evens out the demand on all the phases. The phases used to be red yellow blue, they are now Brown Black and Grey, which is dead useful in the dark for working out which is which isnt it?.. |
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Post by GTCGreg on Feb 6, 2016 17:44:43 GMT
No, TLW is correct. On a 480 volt three phase system, one phase to neutral will give you 277. If you want 240/120, single phase from a 480 volt 3 phase system, they usually use a transformer that is fed by two phases (480 volts) on the primary and then drops that down to 240 with a center tap that is tied to neutral. There are some specially wound 3 phase transformers that have a 240/120 volt tap, but that's not the way it is usually done.  |
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Post by c64 on Feb 6, 2016 18:19:44 GMT
Here, we only use white for neutral. Blue is either one phase of a three-phase circuit or, on a single phase circuit, it's usually a switched circuit such as a wall switch controlling a ceiling light or switched outlet for a floor or table lamp. We don't have white,just grey and it isn't around that long. In the past we only had black and brown for live wires. A standard 5-core cable had one brown and two black so the function depended on the purpose. In case of multiple light switches, the first switch had brown as in and black for the pair of corresponding outgoing wires while the last switch had brown as out. In case of single switch plus outlet, black is often used as in for the outlet and the switch and brown as out - or brown as in and one black as out from the switch which is usually connected to the second black one near the light to prevent the need of checking which black wire was used. For rotary current, it mostly doesn't matter (heaters like stove, flash-heater, boiler) and for motors you just tried if it works. If it doesn't work at all or is wrong, just swap any two wires. Nowadays you need to connect the correct colour to the Line numbers except for the load itself where you mostly connect randomly to prevent imbalancing the grid. |
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Post by c64 on Feb 6, 2016 18:31:59 GMT
The phases used to be red yellow blue, they are now Brown Black and Grey, which is dead useful in the dark for working out which is which isnt it?.. Which is also international. The main reasonfor using those colours is that most males (>60% !!!) are colour ametropic. Most don't even know since most just have a minor red/green weakness. A true red/green blindness is rare and total colour blindness is extremely rare. For women, it is different, less than 8 percent are colour ametropic. So when arguing about colours, ask a women - at least 2 to make sure! So the neutral wire is blue since everybody who might deal with wires can see blue. The few people in the world who can't see blue shouldn't pass any tests to become an electrician or Darwinism takes care of them real soon. PE which is yellow/green can also be seen by all people since they can at least notice the stripes. And even when colour blind (remember they can still see blue), the life wires are just shades of something else. |
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Post by the light works on Feb 6, 2016 18:45:27 GMT
No, TLW is correct. On a 480 volt three phase system, one phase to neutral will give you 277. If you want 240/120, single phase from a 480 volt 3 phase system, they usually use a transformer that is fed by two phases (480 volts) on the primary and then drops that down to 240 with a center tap that is tied to neutral. There are some specially wound 3 phase transformers that have a 240/120 volt tap, but that's not the way it is usually done. it has to do with the sine wave of the electric current. the one Greg showed is what we call an open delta configuration. on that, phase A and C are 120V to neutral and any two phases are 240V phase to phase - but phase B to neutral is about 208 volts. a wye configuration has three 120V transformers each connected from a phase wire to the neutral wire. in both cases, though, the sine wave on three phase power never sees peak to peak voltage, like a single phase sine wave does. when you connect two phases of a three phase system, when one phase is at peak, the other phase, is a third of a cycle off peak.  this means your phase to phase voltage is less than twice your phase to neutral voltage, on a wye connected system. on an open delta, you have a single phase system with a "wild leg" added in for three phase loads. (or more specifically, a three phase single voltage system, with one transformer used as a stepdown transformer to allow single phase loads.) |
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Post by the light works on Feb 6, 2016 18:55:30 GMT
in the US, the grounded (neutral) conductor is white or gray. with large wires, it can be banded with white or gray. the equipment grounding conductor has green on it. - it may be yellow and green in international products, but if it has green it may ONLY be used for equipment grounding. it is permissible to band a white wire in a cable, and use it as a hot wire, but it may not be a switched wire. (this is commonly seen on water heaters and electric heaters, which use only 240V power.)
any other color is a hot wire. commonly a 120/240 or 208 system will use black, red, blue, and white; while 277/480 will use brown, orange, yellow, and gray. (systems of different voltages in the same structure are required to use different colors) a person diagnosed with color blindness may not legally be an electrician in the US. it is also common to see pink and purple wiring in complex systems - those are often used as switched wires in control systems.
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Post by the light works on Feb 6, 2016 19:02:17 GMT
if you upgrade to a heat pump, you are potentially losing efficiency, again. How so? because a conventional heater converts electricity directly into heat. - a light bulb is essentially a conventional heater that has light as a by-product. instead of converting electricity to heat, a heat pump essentially pumps heat from one area to another. think of it as the difference between manufacturing heat, and shipping heat in. |
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Post by the light works on Feb 6, 2016 19:03:58 GMT
Erm, since when?... Three phase, use phase one and two to get 480v, or 2&3 or 3&1, if you just use a single phase and the "Neutral" you only get 240v. The way streets are set out, they send a single phase up street one, then two up street two, then three up three, then start again, this evens out the demand on all the phases. The phases used to be red yellow blue, they are now Brown Black and Grey, which is dead useful in the dark for working out which is which isnt it?.. so you don't actually have three phases in an individual house? |
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Post by c64 on Feb 6, 2016 19:06:34 GMT
in the US, the grounded (neutral) conductor is white or gray. with large wires, it can be banded with white or gray. the equipment grounding conductor has green on it. - it may be yellow and green in international products, but if it has green it may ONLY be used for equipment grounding. it is permissible to band a white wire in a cable, and use it as a hot wire, but it may not be a switched wire. (this is commonly seen on water heaters and electric heaters, which use only 240V power.) any other color is a hot wire. commonly a 120/240 or 208 system will use black, red, blue, and white; while 277/480 will use brown, orange, yellow, and gray. (systems of different voltages in the same structure are required to use different colors) a person diagnosed with color blindness may not legally be an electrician in the US. it is also common to see pink and purple wiring in complex systems - those are often used as switched wires in control systems. During WW-2, one of my ancestors was almost court-martialled and shot since he confused signal flares. Fortunately there was a doctor around who knew that colour blindness exist. |
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Post by c64 on Feb 6, 2016 19:09:01 GMT
because a conventional heater converts electricity directly into heat. - a light bulb is essentially a conventional heater that has light as a by-product. instead of converting electricity to heat, a heat pump essentially pumps heat from one area to another. think of it as the difference between manufacturing heat, and shipping heat in. Most of the electric work in a heat pump comes out as heat inside your building so you get heat from outside PLUS heat from your spent electricity. I can't see how this shouldn't be efficient! |
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Post by the light works on Feb 6, 2016 19:42:49 GMT
we also have our meter separate from our breaker panel for the most part. this is a typical meter installation and one of my panels. Attachment DeletedAttachment DeletedAttachment Deletedthe four with the reflective labels are the arc fault protected general power circuits. the rest are specific circuits that don't require arc fault protection. |
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Post by the light works on Feb 6, 2016 19:48:49 GMT
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Post by wvengineer on Feb 6, 2016 21:16:52 GMT
because a conventional heater converts electricity directly into heat. - a light bulb is essentially a conventional heater that has light as a by-product. instead of converting electricity to heat, a heat pump essentially pumps heat from one area to another. think of it as the difference between manufacturing heat, and shipping heat in. Most of the electric work in a heat pump comes out as heat inside your building so you get heat from outside PLUS heat from your spent electricity. I can't see how this shouldn't be efficient! It is if you are running the system in cooling mode. |
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Post by wvengineer on Feb 6, 2016 21:26:02 GMT
Depends on the local codes. For my area, they are just required in bedroom. GFCI's are required for wet areas. Wet area includes Kitchens, bathrooms, laundry rooms, and basements. So basement bedrooms require both Arc Fault and GFCI. Those combo breakers are something like $50-70. Some people will install arc fault breakers and then put the first outlet on the circuit as a GFCI outlet, but those are more sensitive to tripping. national code requires them everywhere - local codes may choose to not recognize the national requirement. here, GFCI protection is only in unfinished basements, not living space. (if your basement bedroom is a wet location there is another code that outlaws that) the manufacturer I get breakers from only makes combination breakers. they also have indicator lights to let you know what condition led to a trip. Here all of a below grade construction is considered "wet" meaning that all outlets are required to be GFCI's at either the breaker or first outlet on the circuit. Given the problems I have had with basement moisture and I know people who have had flooding to one degree or another, it makes sense to me. One question I have is on a 240V outlet (typically clothes dryers). I don't even know if you can get a 2-pole GFCI. |
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Post by the light works on Feb 6, 2016 23:17:45 GMT
national code requires them everywhere - local codes may choose to not recognize the national requirement. here, GFCI protection is only in unfinished basements, not living space. (if your basement bedroom is a wet location there is another code that outlaws that) the manufacturer I get breakers from only makes combination breakers. they also have indicator lights to let you know what condition led to a trip. Here all of a below grade construction is considered "wet" meaning that all outlets are required to be GFCI's at either the breaker or first outlet on the circuit. Given the problems I have had with basement moisture and I know people who have had flooding to one degree or another, it makes sense to me. One question I have is on a 240V outlet (typically clothes dryers). I don't even know if you can get a 2-pole GFCI. absolutely. how do you think we protect hot tubs? |
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Post by silverdragon on Feb 7, 2016 8:08:52 GMT
The way streets are set out, they send a single phase up street one, then two up street two, then three up three, then start again, this evens out the demand on all the phases. The phases used to be red yellow blue, they are now Brown Black and Grey, which is dead useful in the dark for working out which is which isnt it?.. so you don't actually have three phases in an individual house? No, not usually, unless you ask for it and have three separate supplies, three meters, three circuit breaker fuse boxes, or ask for a 480v and show good cause to need one, and that would need to be a very large house. Domestic supply is usually 240v, they dont "trust" us with the big boys stuff. I suppose it depends on the delta wye on what you get in flavours of voltage, but I was always told that 480v "breaks down" to 240v from the substation and thats how its sent down the road, as either domestic or industrial. We never got much into other countries supplies, as this was IEE 16th edition UK (at the end) electrical supplies, as we were working in UK. |
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