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#1
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GFCI Circuit protection question-outdoor wiring
OK complicasted question, maybe...
I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c |
#2
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I think you are going about the project wrong. All outlets in the shed need
to be GFCI protected. There are code issues when running multiple circuits to an out building like disconnects, so probably the most sensible thing to do is install a thirty or forty amp feeder(10/3G) or (8/3G) and small panel in the shed "chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c |
#3
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RBM wrote:
I think you are going about the project wrong. All outlets in the shed need to be GFCI protected. There are code issues when running multiple circuits to an out building like disconnects, so probably the most sensible thing to do is install a thirty or forty amp feeder(10/3G) or (8/3G) and small panel in the shed "chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c All outlets in the shed WILL be GFCI protected. They will run off the GFCI outlet from the house, which will protect the whole circuit downstream. |
#4
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If you decide to connect your heater with a cord and outlet, even 240 volt,
it will require GFCI protection as well "chester" wrote in message ... RBM wrote: I think you are going about the project wrong. All outlets in the shed need to be GFCI protected. There are code issues when running multiple circuits to an out building like disconnects, so probably the most sensible thing to do is install a thirty or forty amp feeder(10/3G) or (8/3G) and small panel in the shed "chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c All outlets in the shed WILL be GFCI protected. They will run off the GFCI outlet from the house, which will protect the whole circuit downstream. |
#5
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RBM wrote:
If you decide to connect your heater with a cord and outlet, even 240 volt, it will require GFCI protection as well Yeah well, the heater will be hard-wired in, not on an outlet. I dont think it will sepcificaly require GFCI, but I am not sure. I guess this issue is that accessory structures may be limited in general to one breaker off the main panel, which is the problem now, since I want a 240V heater (not 120) and so need either two lines/breakers, or a sub-panel. I had orignially been considering a subpanel, but was steered away from that idea by some people. I suppose code could be different here (in seattle) but I dont really know. Guess I better check on it. I guess my choices are -keep it the same and not worry about it (what is the harm in having two circuits off the main panel? -change the heater to 120V, deal with smaller heating capacity, and use the two wires I have already started running (they are not underground) to one dual 20A circuit -change the wiring to 10/3 w/g and run a 30A subpanel, wasting the $44 I spent on 250ft of 12/2 w/g and the time under the house dunno what sbest All outlets in the shed WILL be GFCI protected. They will run off the GFCI outlet from the house, which will protect the whole circuit downstream. |
#6
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If the heater is hard wired, it doesn't need GFCI protection (NEC)
"chester" wrote in message ... RBM wrote: If you decide to connect your heater with a cord and outlet, even 240 volt, it will require GFCI protection as well Yeah well, the heater will be hard-wired in, not on an outlet. I dont think it will sepcificaly require GFCI, but I am not sure. I guess this issue is that accessory structures may be limited in general to one breaker off the main panel, which is the problem now, since I want a 240V heater (not 120) and so need either two lines/breakers, or a sub-panel. I had orignially been considering a subpanel, but was steered away from that idea by some people. I suppose code could be different here (in seattle) but I dont really know. Guess I better check on it. I guess my choices are -keep it the same and not worry about it (what is the harm in having two circuits off the main panel? -change the heater to 120V, deal with smaller heating capacity, and use the two wires I have already started running (they are not underground) to one dual 20A circuit -change the wiring to 10/3 w/g and run a 30A subpanel, wasting the $44 I spent on 250ft of 12/2 w/g and the time under the house dunno what sbest All outlets in the shed WILL be GFCI protected. They will run off the GFCI outlet from the house, which will protect the whole circuit downstream. |
#7
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"chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... I think that this is a mistake. I run some pretty heavy loads in my garage. Sharing the circuitry with god only know what else could cause tripping of the gfci BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c There are several critical pieces of this puzzle that are not included. What is the distance to the new loads? My calculations say that your new load (heater) must be less than 145 feet total wire length. Fixed pieces of equipment are not required to be gfci protected. That does not mean that it is not a good idea. Any flammable liquids out in the new area? Other threads seem to indicate that you already bought the wire. Was the wire UF cable? NM as far as I know is not rated for direct burial. Not knowing the path of the electrical run and the use of the area. 12 inches could be to shallow. 24 would be fine in all situations. |
#8
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SQLit wrote:
"chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... I think that this is a mistake. I run some pretty heavy loads in my garage. Sharing the circuitry with god only know what else could cause tripping of the gfci Well, the circuitry to the shed running the outlets and lighting is to be a dedicated 20a/120v circuit. the only other outlet outside the shed on this circuit will be the one outside at the house, which will rarely be in use for anything. BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c There are several critical pieces of this puzzle that are not included. What is the distance to the new loads? My calculations say that your new load (heater) must be less than 145 feet total wire length. Fixed pieces of equipment are not required to be gfci protected. That does not mean that it is not a good idea. Any flammable liquids out in the new area? The distance is about 70-80 feet. Ther ewill be no flammable liquids kept in the area. finished shed for storage/excercise, TV etc. Other threads seem to indicate that you already bought the wire. Was the wire UF cable? NM as far as I know is not rated for direct burial. The wire I bought was UF cable 12/2 w/g Not knowing the path of the electrical run and the use of the area. 12 inches could be to shallow. 24 would be fine in all situations. I am going for 18-24, with PVC conduit. Thanks for you input/questions. I was concerned with the two separate circuits, but I found NEC code online, and found there are exceptions to the rule of one circuit (including multi-branch) to an external structure. One exception is when different voltages are supplied with the two lines. This appears to apply to my situation. i feel a whole lot more comfortable with two circuits, than running one multi-brnach circuit with a 240V and 120V running off of it. |
#9
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The rule is you can only run one circuit or feeder to a second building. You will either be stuck with a sub panel (ground rods, disconnect etc) or you could run a 20a 240v (3 wire + ground) circuit and split it out into 2 multiwire 120v circuuits that also share the 250v load (hold your nose legal) and use GFCI receptacles in the shed. That will limit you to about 11a per 120v circuit since your heater pulls 8.3. If you just want a light and some occasional power tool use that may be fine. The heater and lights do not need to be GFCI but a direct bury cable would have to be 24" down. Wire in conduit can be 18". 120v 15 or 20a GFCI protected circuits can be 12" down Frost heaving might make all this moot anyway. You might need to be below the frost line. I don't know much about things that happen below freezing. I appreciate the input. I admit I didnt know about this rule. You got me stressd out a bit, so I actually found the NEC online. It doesn't let you cut and paste, but basically, rule 225.30 states that there is only to be one feeder or brnach circuit to each structure on a property, "unless permitted in 225.30(A)though(E). Subsection (D) states that "Additional feeders or branch circuits shall be permitted for different voltages, frequencies, or pahses or for different uses such as control of outside lighting from multiple locations." This would seem to apply to me, since I need 120V and 240V. I feel much more comfortable using two feeder circuits for my applications than using a multiwire branch circuit and running 120V and 240V off that same circuit, as you mentioned (I didnt know this was possible, but I guess it is always an option). Thanks. |
#10
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I might be wrong but I do not think your application would permit two
feeders under the different voltages provision since the 120 volts is derived as one leg of the 240 volts and thereby CAN be provided from one feeder. Such a provision would apply if you were supplying 480 and 120 volts, where two panels would be required. You might be more comfortable with two feeders but that is not the normal way it's done. I think the primary consideration is that in a fire or other emergency it is possible for emergency personnel to shut off all power to a structure by killing the feed without having to figure out if there might be others. Don Young "chester" wrote in message ... SQLit wrote: "chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... I think that this is a mistake. I run some pretty heavy loads in my garage. Sharing the circuitry with god only know what else could cause tripping of the gfci Well, the circuitry to the shed running the outlets and lighting is to be a dedicated 20a/120v circuit. the only other outlet outside the shed on this circuit will be the one outside at the house, which will rarely be in use for anything. BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c There are several critical pieces of this puzzle that are not included. What is the distance to the new loads? My calculations say that your new load (heater) must be less than 145 feet total wire length. Fixed pieces of equipment are not required to be gfci protected. That does not mean that it is not a good idea. Any flammable liquids out in the new area? The distance is about 70-80 feet. Ther ewill be no flammable liquids kept in the area. finished shed for storage/excercise, TV etc. Other threads seem to indicate that you already bought the wire. Was the wire UF cable? NM as far as I know is not rated for direct burial. The wire I bought was UF cable 12/2 w/g Not knowing the path of the electrical run and the use of the area. 12 inches could be to shallow. 24 would be fine in all situations. I am going for 18-24, with PVC conduit. Thanks for you input/questions. I was concerned with the two separate circuits, but I found NEC code online, and found there are exceptions to the rule of one circuit (including multi-branch) to an external structure. One exception is when different voltages are supplied with the two lines. This appears to apply to my situation. i feel a whole lot more comfortable with two circuits, than running one multi-brnach circuit with a 240V and 120V running off of it. |
#11
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Don Young wrote:
I might be wrong but I do not think your application would permit two feeders under the different voltages provision since the 120 volts is derived as one leg of the 240 volts and thereby CAN be provided from one feeder. Such a provision would apply if you were supplying 480 and 120 volts, where two panels would be required. You might be more comfortable with two feeders but that is not the normal way it's done. I think the primary consideration is that in a fire or other emergency it is possible for emergency personnel to shut off all power to a structure by killing the feed without having to figure out if there might be others. Don Young So is it legit to run a multiwire off of dual 20A, and run the outlets off of hot neutral, and run the 240V off of both hots? I mean, I can do that easily, with the current wiring. I just would think two circuits would be better/safer. But obviouosly NEC has its reasons. However, I cant help but wonder why there would be exceptions for higher voltage but not 120 and 240 circuits. For that You would have to turn off two circuits as well. ? |
#12
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#13
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SQLit wrote: I think that this is a mistake. I run some pretty heavy loads in my garage. Sharing the circuitry with god only know what else could cause tripping of the gfci And of course, you don't know what is going on in the house at the GFCI outlet. If it's the bathroom outlet and somebody plugs in the hair drier while you're using the garage door opener or something .... (see the bathroom GFCI outlet thread) |
#14
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#15
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I appreciate the input. I admit I didnt know about this rule. You got me stressd out a bit, so I actually found the NEC online. It doesn't let you cut and paste, but basically, rule 225.30 states that there is only to be one feeder or brnach circuit to each structure on a property, "unless permitted in 225.30(A)though(E). Subsection (D) states that "Additional feeders or branch circuits shall be permitted for different voltages, frequencies, or pahses or for different uses such as control of outside lighting from multiple locations." This would seem to apply to me, since I need 120V and 240V. I feel much more comfortable using two feeder circuits for my applications than using a multiwire branch circuit and running 120V and 240V off that same circuit, as you mentioned (I didnt know this was possible, but I guess it is always an option). Thanks. I don't understand the resistance to running a 3-wire, 240V, 50A run to a sub-panel, and dropping a local ground. Why put so much thought and effort into finding a safe, legal way to do it wrong? |
#16
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Goedjn wrote:
I appreciate the input. I admit I didnt know about this rule. You got me stressd out a bit, so I actually found the NEC online. It doesn't let you cut and paste, but basically, rule 225.30 states that there is only to be one feeder or brnach circuit to each structure on a property, "unless permitted in 225.30(A)though(E). Subsection (D) states that "Additional feeders or branch circuits shall be permitted for different voltages, frequencies, or pahses or for different uses such as control of outside lighting from multiple locations." This would seem to apply to me, since I need 120V and 240V. I feel much more comfortable using two feeder circuits for my applications than using a multiwire branch circuit and running 120V and 240V off that same circuit, as you mentioned (I didnt know this was possible, but I guess it is always an option). Thanks. I don't understand the resistance to running a 3-wire, 240V, 50A run to a sub-panel, and dropping a local ground. Why put so much thought and effort into finding a safe, legal way to do it wrong? Well, mostly becasue I already spent $ on the 12/2 w/g wire. I will waste $45, which isnt a big deal, and about 2-3 hours in labor. I am stillthnking subpanel, but was thinking just a 30A, using 10/3 w/g. I would think that would be sufficient for my needs, but I guess it will not give me any expandabilityy. Waht wire for 50A? 8awg? |
#17
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chester wrote:
RBM wrote: I think you are going about the project wrong. All outlets in the shed need to be GFCI protected. There are code issues when running multiple circuits to an out building like disconnects, so probably the most sensible thing to do is install a thirty or forty amp feeder(10/3G) or (8/3G) and small panel in the shed "chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c Running two branch circuits between buildings is a violation of "225.30 Number of Supplies. Where more than one building or other structure is on the same property and under single management, each additional building or other structure served that is on the load side of the service disconnecting means shall be supplied by one feeder or branch circuit..." This provision of the US NEC is meant to prevent elecctrical accident caused by multiple sources of current to a buiding. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison |
#18
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-- Tom Horne Well we aren't no thin blue heroes and yet we aren't no blackguards to. We're just working men and woman most remarkable like you. -- Tom Horne Well we aren't no thin blue heroes and yet we aren't no blackguards to. We're just working men and woman most remarkable like you.RBM wrote: I think you are going about the project wrong. All outlets in the shed need to be GFCI protected. There are code issues when running multiple circuits to an out building like disconnects, so probably the most sensible thing to do is install a thirty or forty amp feeder(10/3G) or (8/3G) and small panel in the shed "chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c RBM wrote: "chester" wrote in message ... OK complicasted question, maybe... I am wiring my (large) shed now, and have decided to do two dedicated circuits. 1 Circuit will be a single 20A/120V for all the outlets and lighting. It will be GFCI-protected at the house-when the wiring exits the house, I simply added an outdoor GFCI outlet, and put the shed load out of this outlet. So all the outlets, and lighting in the shed will run off this circuit. Easy enough... BUT, I also am wiring 240V out there-for a 240V-2000W in-wall electric heater. I am assuming I need to GFCI-protect this line as well, but maybe I don't. I know the heater itself has a breaker in it (dunno if that is GFCI or not?),but do I need to protect the line from the house (buried 12-24" down in the ground)? I would think I need to, but maybe in-wall heaters do not need to be on GFCI circuits, and/or maybe the buried cable does not need to be protected with GFCI? Thanks for the help c RBM wrote: I think you are going about the project wrong. All outlets in the shed need to be GFCI protected. There are code issues when running multiple circuits to an out building like disconnects, so probably the most sensible thing to do is install a thirty or forty amp feeder(10/3G) or (8/3G) and small panel in the shed "chester" wrote in message ... All outlets in the shed WILL be GFCI protected. They will run off the GFCI outlet from the house, which will protect the whole circuit downstream. RBM wrote: If you decide to connect your heater with a cord and outlet, even 240 volt, it will require GFCI protection as well Would you mind quoting chapter and verse for the code language you believe requires GFCI protection for 240 volt cord and plug conneccted devices? -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison |
#19
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gk wrote:
The rule is you can only run one circuit or feeder to a second building. You will either be stuck with a sub panel (ground rods, disconnect etc) or you could run a 20a 240v (3 wire + ground) circuit and split it out into 2 multiwire 120v circuuits that also share the 250v load (hold your nose legal) and use GFCI receptacles in the shed. That will limit you to about 11a per 120v circuit since your heater pulls 8.3. If you just want a light and some occasional power tool use that may be fine. The heater and lights do not need to be GFCI but a direct bury cable would have to be 24" down. Wire in conduit can be 18". 120v 15 or 20a GFCI protected circuits can be 12" down Frost heaving might make all this moot anyway. You might need to be below the frost line. I don't know much about things that happen below freezing. I appreciate the input. I admit I didnt know about this rule. You got me stressd out a bit, so I actually found the NEC online. It doesn't let you cut and paste, but basically, rule 225.30 states that there is only to be one feeder or brnach circuit to each structure on a property, "unless permitted in 225.30(A)though(E). Subsection (D) states that "Additional feeders or branch circuits shall be permitted for different voltages, frequencies, or pahses or for different uses such as control of outside lighting from multiple locations." This would seem to apply to me, since I need 120V and 240V. I feel much more comfortable using two feeder circuits for my applications than using a multiwire branch circuit and running 120V and 240V off that same circuit, as you mentioned (I didnt know this was possible, but I guess it is always an option). Thanks. I'm afraid it does not apply to you because the voltage to ground on both circuits is 120 volts. You can run a multiwire branch circuit that can carry both loads but that would still mean changing the line to three wire plus ground. If you were trying to avoid the installation of a grounding electrode system at the garage it is a bad idea even were the code permits it. A multiwire branch circuit is a single branch circuit for the purposes of the code so a building supplied by one of those circuits does not require a grounding electrode system at the building supplied. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison |
#20
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gk wrote:
Goedjn wrote: I appreciate the input. I admit I didnt know about this rule. You got me stressd out a bit, so I actually found the NEC online. It doesn't let you cut and paste, but basically, rule 225.30 states that there is only to be one feeder or brnach circuit to each structure on a property, "unless permitted in 225.30(A)though(E). Subsection (D) states that "Additional feeders or branch circuits shall be permitted for different voltages, frequencies, or pahses or for different uses such as control of outside lighting from multiple locations." This would seem to apply to me, since I need 120V and 240V. I feel much more comfortable using two feeder circuits for my applications than using a multiwire branch circuit and running 120V and 240V off that same circuit, as you mentioned (I didnt know this was possible, but I guess it is always an option). Thanks. I don't understand the resistance to running a 3-wire, 240V, 50A run to a sub-panel, and dropping a local ground. Why put so much thought and effort into finding a safe, legal way to do it wrong? Well, mostly becasue I already spent $ on the 12/2 w/g wire. I will waste $45, which isnt a big deal, and about 2-3 hours in labor. I am stillthnking subpanel, but was thinking just a 30A, using 10/3 w/g. I would think that would be sufficient for my needs, but I guess it will not give me any expandability. What wire for 50A? 8awg? What is the total length of the circuit from the service equipment to the garage? With that information I can find the voltage drop for the circuit. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison |
#21
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#22
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gk wrote:
Don Young wrote: I might be wrong but I do not think your application would permit two feeders under the different voltages provision since the 120 volts is derived as one leg of the 240 volts and thereby CAN be provided from one feeder. Such a provision would apply if you were supplying 480 and 120 volts, where two panels would be required. You might be more comfortable with two feeders but that is not the normal way it's done. I think the primary consideration is that in a fire or other emergency it is possible for emergency personnel to shut off all power to a structure by killing the feed without having to figure out if there might be others. Don Young So is it legit to run a multiwire off of dual 20A, and run the outlets off of hot neutral, and run the 240V off of both hots? I mean, I can do that easily, with the current wiring. I just would think two circuits would be better/safer. But obviouosly NEC has its reasons. However, I cant help but wonder why there would be exceptions for higher voltage but not 120 and 240 circuits. For that You would have to turn off two circuits as well. ? The higher voltages cannot be derived from the same circuit without installing a transformer so the code language permits you to avoid that bit of expense and complexity. The code language on which you are relying is meant to allow separate circuits for such purposes as powering a large item of equipment that requires a completely different voltage such as 240 volt delta three phase with one phase grounded to run a large refrigeration unit. You need the 240 / 3 phase power for the refrigeration unit and you need 120 volt power for service receptacles and lighting. Since 240 volt delta is much cheaper to install as corner grounded delta the cost effective way to provide both voltages is to run two circuits. Another example is a guard house for an industrial complex that has 480/277 volt air conditioning and lighting together with 208/120 volt power for receptacles. In short those exceptions are only intended to be applied were a single branch circuit or feeder cannot supply the needed power. -- Tom Horne Well we aren't no thin blue heroes and yet we aren't no blackguards to. We're just working men and woman most remarkable like you. |
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Well, mostly becasue I already spent $ on the 12/2 w/g wire. I will waste $45, which isnt a big deal, and about 2-3 hours in labor. I am stillthnking subpanel, but was thinking just a 30A, using 10/3 w/g. I would think that would be sufficient for my needs, but I guess it will not give me any expandabilityy. Waht wire for 50A? 8awg? You can use much of the 12-AWG for wiring inside the shed, so it's not a total loss. you said somewhere that the run was around 70', so I think that 8AWG wire will get you 40A (well, 46, but I don't think they make 45A breakers) Anyway, a 40-Amp 2-pole breaker gets you a nominal 9600 watts, to divide up into 240V and 120V circuts however you want. |
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What is the total length of the circuit from the service equipment to the garage? With that information I can find the voltage drop for the circuit. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison it is approximatley 75 feet |
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gk wrote:
What is the total length of the circuit from the service equipment to the garage? With that information I can find the voltage drop for the circuit. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison it is approximatley 75 feet #6 AWG aluminum wire carrying fifty amperes would have a voltage drop of 2.1 %. -- Tom Horne Well we aren't no thin blue heroes and yet we aren't no blackguards to. We're just working men and woman most remarkable like you. |
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Goedjn wrote
You can use much of the 12-AWG for wiring inside the shed, so it's not a total loss. you said somewhere that the run was around 70', so I think that 8AWG wire will get you 40A (well, 46, but I don't think they make 45A breakers) Anyway, a 40-Amp 2-pole breaker gets you a nominal 9600 watts, to divide up into 240V and 120V circuts however you want. OK OK I have decided to run a subpanel. BUT cripes, while the subpanels are cheap, man, 8/3 AWG is PRICY. OK so using substantially cheaper 10/3 AWG gives me a 30A subpanel. I would think this would be sufficient: 2000W heater, plus antoher 1000W for outlets and such, gives me ~15A, assuming full useage? 30A seems like it would be sufficient, and a LOT cheaper. Comments? thx |
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OK OK I have decided to run a subpanel. BUT cripes, while the subpanels are cheap, man, 8/3 AWG is PRICY. OK so using substantially cheaper 10/3 AWG gives me a 30A subpanel. I would think this would be sufficient: 2000W heater, plus antoher 1000W for outlets and such, gives me ~15A, assuming full useage? 30A seems like it would be sufficient, and a LOT cheaper. Comments? thx What are you using the shed for, again? And what's the price difference, and does that price difference change if you go to conduit and/or individual strand? 30A is probably enough for a home workshop with one user, and if you use conduit, you can always swap out the feeder and breaker(s) if you decide to upgrade. (Although if we were making stone soup, I'd observer that having a few extra amps for an arc-welder is always, good, and wouldn't it be nice to be able to put in AC and a refridgerator?...) --Goedjn |
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chester wrote:
wrote: On Mon, 26 Sep 2005 19:56:31 -0700, chester wrote: OK OK I have decided to run a subpanel. BUT cripes, while the subpanels are cheap, man, 8/3 AWG is PRICY. OK so using substantially cheaper 10/3 AWG gives me a 30A subpanel. I would think this would be sufficient: 2000W heater, plus antoher 1000W for outlets and such, gives me ~15A, assuming full useage? 30A seems like it would be sufficient, and a LOT cheaper. Comments? Get a 2/4 disconnect and install one 15a 2 pole for the heat and two 20a single pole for the 120v loads. Put a GFCI receptacle for the first receptacle on each circuit. You can put the lights on the non-GFCI side. "Diversity" will keep you out of trouble. Be sure to get the suplimental grounding bus, don't install the bonding screw, drive a rod (goes to the grounding bus). SO your thinking 30A would be sufficient to serve my needs? I mean, I could add a 3000W device(s) and still be under... I got a 100A sub-panel, the grounding bus, will NOT bond the neutral, and will eventually add a gounding rod outside. But do I really need a disconnect? The US NEC requires a disconnecting means for each separate structure. "225.31 Disconnecting Means. Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure. 225.32 Location. The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in 230.6 shall be permitted to be utilized." So as long as your panel is located "at a readily accessible location nearest the point of entrance of the conductors" all you have to do is install a double pole breaker with a breaker tie down kit and feed your supply into the breakers terminals. That breaker is then the service disconnecting means for the shed. The phrase "nearest the point of entrance of the conductors" is generally held to mean not more than five linear or ten wire feet from were the conductors enter the structure. Since, IIRC, you are in Washington State you would be under the Uniform Building Code (UBC). The UBC has no rules about whether the disconnect is inside or outside of the structure. The Southern Building Code required and exterior disconnecting means at one time. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison |
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The US NEC requires a disconnecting means for each separate structure. "225.31 Disconnecting Means. Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure. 225.32 Location. The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in 230.6 shall be permitted to be utilized." So as long as your panel is located "at a readily accessible location nearest the point of entrance of the conductors" all you have to do is install a double pole breaker with a breaker tie down kit and feed your supply into the breakers terminals. That breaker is then the service disconnecting means for the shed. The phrase "nearest the point of entrance of the conductors" is generally held to mean not more than five linear or ten wire feet from were the conductors enter the structure. Since, IIRC, you are in Washington State you would be under the Uniform Building Code (UBC). The UBC has no rules about whether the disconnect is inside or outside of the structure. The Southern Building Code required and exterior disconnecting means at one time. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison OK so just add a double pole 30A breaker as a main breaker in the panel. |
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chester wrote:
The US NEC requires a disconnecting means for each separate structure. "225.31 Disconnecting Means. Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure. 225.32 Location. The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in 230.6 shall be permitted to be utilized." So as long as your panel is located "at a readily accessible location nearest the point of entrance of the conductors" all you have to do is install a double pole breaker with a breaker tie down kit and feed your supply into the breakers terminals. That breaker is then the service disconnecting means for the shed. The phrase "nearest the point of entrance of the conductors" is generally held to mean not more than five linear or ten wire feet from were the conductors enter the structure. Since, IIRC, you are in Washington State you would be under the Uniform Building Code (UBC). The UBC has no rules about whether the disconnect is inside or outside of the structure. The Southern Building Code required and exterior disconnecting means at one time. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison OK so just add a double pole 30A breaker as a main breaker in the panel. Yes with a breaker tie down kit provided that the panel is mounted "nearest the point of entrance of the conductors." -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison |
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HorneTD wrote:
"This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison Edison must have known AMUN... |
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Goedjn wrote:
OK OK I have decided to run a subpanel. BUT cripes, while the subpanels are cheap, man, 8/3 AWG is PRICY. OK so using substantially cheaper 10/3 AWG gives me a 30A subpanel. I would think this would be sufficient: 2000W heater, plus antoher 1000W for outlets and such, gives me ~15A, assuming full useage? 30A seems like it would be sufficient, and a LOT cheaper. Comments? thx What are you using the shed for, again? And what's the price difference, and does that price difference change if you go to conduit and/or individual strand? Well, it is actually more like a backyard "cabin". About 250 sq feet, with one indoor light fixture, one outdoor motion-activated light. it willl have a couch, a table and a desk. It is like adding a room on to a house I figure. Electrical load will be TV, heater, maybe a tredmill, light, etc. Light electircal load, I think. Occaisonally I willl be running a miter saw or skill saw, or some other power tool. One at a time, always. I think 30A is enogh, but I will run conduit, in case I want to change. I wonder, if I run conduit, the whole way out, even if it is underground, do I need UF cable? 30A is probably enough for a home workshop with one user, and if you use conduit, you can always swap out the feeder and breaker(s) if you decide to upgrade. (Although if we were making stone soup, I'd observer that having a few extra amps for an arc-welder is always, good, and wouldn't it be nice to be able to put in AC and a refridgerator?...) --Goedjn |
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gk wrote:
Goedjn wrote: OK OK I have decided to run a subpanel. BUT cripes, while the subpanels are cheap, man, 8/3 AWG is PRICY. OK so using substantially cheaper 10/3 AWG gives me a 30A subpanel. I would think this would be sufficient: 2000W heater, plus antoher 1000W for outlets and such, gives me ~15A, assuming full useage? 30A seems like it would be sufficient, and a LOT cheaper. Comments? thx What are you using the shed for, again? And what's the price difference, and does that price difference change if you go to conduit and/or individual strand? 30A is probably enough for a home workshop with one user, and if you use conduit, you can always swap out the feeder and breaker(s) if you decide to upgrade. (Although if we were making stone soup, I'd observer that having a few extra amps for an arc-welder is always, good, and wouldn't it be nice to be able to put in AC and a refridgerator?...) --Goedjn Well, it is actually more like a backyard "cabin". About 250 sq feet, with one indoor light fixture, one outdoor motion-activated light. it will have a couch, a table and a desk. It is like adding a room on to a house I figure. Electrical load will be TV, heater, maybe a treadmill, light, etc. Light electrical load, I think. Occasionally I will be running a miter saw or skill saw, or some other power tool. One at a time, always. I think 30A is enough, but I will run conduit, in case I want to change. I wonder, if I run conduit, the whole way out, even if it is underground, do I need UF cable? No you do not need UF or any other form of cable in conduit. You can run individual conductors that are suitable for wet locations such as very commonly available THWN. T = Thermoplastic, H = High temperature @ 75 degree centigrade temperature rating of the insulation, W = Wet locations, N = Nylon coated. -- Tom Horne "This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison |
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HorneTD wrote:
Most Firefighters do not pull meters because they can fail explosively when that is improperly done. What we do is to open all of the utility disconnects we can find. Could you describe how it is "improperly done"? [I'm not challenging what you said.] Bud-- |
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