240 vs 120

To the experts,
I am very new to electrical engineering so I will attempt to provide a
clear question. If further details are needed please let me know. The
situation is as follows. I have an older house that I just purchased and I
would like to convert one of the bedrooms into a laundry room. There is
currently a base board heater in the room that is serviced via a 240
circuit. There are 2 30amp breakers servicing this circuit. My question is
this. It seems that 120 volt devices need a return path back but that 240
circuits do not. Is this correct? Would I simply take each of the 2 wires
and attach a wall connector to them for servicing my dryer. Also, as I
stated earlier this is an older house and there is no ground wire in the
room. The base board heater is not connected to a ground. Is this a
potential hazard waiting to happen?
Thank you for your time,
Carl.
Reply to
Carl Lovejoy
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Running a dryer or any piece of equipment with out a ground is nuts/dangerous/crazy ( you pick the word ). Not even considering the code implications. Unless of course it is double insulated, or designed to be operated safely with out a ground.
2002 code requires 4 wires for a dryer and stove now. 2 hots, neutral and ground.
I suggest that you install an new 4 wire cable and outlet for the dryer, and disconnect the "accident looking for a place to happen".
Reply to
SQLit
Thank you very much. That brings up a further question as to why the house was wired without ground? The entire house has outlets that are just 2 prong with no ground. If I were to install a new 4 wire circuit I would have to run this all the way back to the service panel and install new breakers or is there any way to use the existing circuitry in the room? This seems like it's going to get expensive.
Thanks again for your quick reply, Carl.
Reply to
Carl Lovejoy
Are you certain that there are no return wires? Did you look in the box?
The reason that a return is not used with the heaters is that there are no 120 volt devices on either leg. However, a dryer needs 120 to run the motor and timers, therefore must have a return.
Most areas did not require ground wires until about 50 years ago.
What type of wire was used? Even 50 years ago I would have expected to see a three wire cable supplying a 240 volt load, even if the return was not simply tied back.
Of course running new 4 wire is most likely required for all renovations.
If the original was run through metal conduit that provides a ground but can't be used for return.
Carl Lovejoy wrote:
Reply to
Rich256
I'm not 100% positive on the return. I will inspect it deeper tonight after work. I can confirm that there is only 2 wires not 3. My main concern here is that the entire house is wired without ground. My natural question is why was this done? If this is truly a hazard (and I run a lot of computers) then I should have an electrician re-wire the entire house?
Thanks, Carl.
Reply to
Carl Lovejoy
I would not call it a really bad hazard. I don't think there were ground wires in any house built before about 1965
If concerned about safety install GFCIs.
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You can probably find quite a bit of discussion on that subject around the web:
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Carl Lovejoy wrote:
Reply to
Rich256
The common household electric dryer has a 240 volt heating element and a 120 volt motor. A 30 ampere 2-pole breaker with 4 wire No. 10/3 with ground NM cable is permitted to supply the dryer outlet which is required to be four wire - 240/120 volts with ground. All the circuit conductors are required to be in the same cable (or raceway). You are not permitted to use both cables to derive the necessary conductors. Not too long ago a 3 wire 10/2 with ground could be used on a 2 pole 30 ampere breaker where the grounded conductor was allowed to also serve as the grounding conductor. This is no longer allowed.
The baseboard heaters are required to be grounded using an equipment grounding conductor. If the baseboard heaters are not grounded they are a potential serious electrical hazard.
Reply to
electrician
"Carl Lovejoy" wrote in news: snipped-for-privacy@giganews.com:
Check the wire insulation. If it is braided paper or cloth (usually coated with a tar-like substance), I would definately re-wire the house. Left undisturbed, rodent-free, in a minimal-vibration environment and never overloaded, it is probably still safe, but I wouldn't bet on it. That type of insulation is so old it has broken down by now, and is a fire hazard. If you disturb the wires, you will see it usually just crumbling and falling off.
Reply to
Anthony
The NEC allows a fix for existing homes that do not have an equipment ground. You can install GFCI receptacles that give some margin of safety and meet the NEC, and some bank loan requirements. Last year I installed over 30 GFCI receptacles in my mother's home that did not have equipment grounding conductors so the she could get a pre-sell inspection approved. As far as the computer, I ran a computer for two years in an older home that did not have a grounding conductor and it worked fine, but I did use all small UPS power unit.
I wrote an article titled How to Ground a Nongrounding-type Receptacle in 1996 based on the 1996 NEC that is at
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Here are the 2005 NEC requirements:
VII. Methods of Equipment Grounding 250.130 Equipment Grounding Conductor Connections. Equipment grounding conductor connections at the source of separately derived systems shall be made in accordance with 250.30(A)(1). Equipment grounding conductor connections at service equipment shall be made as indicated in 250.130(A) or (B). For replacement of non-grounding-type receptacles with grounding-type receptacles and for branch-circuit extensions only in existing installations that do not have an equipment grounding conductor in the branch circuit, connections shall be permitted as indicated in 250.130(C). (A) For Grounded Systems. The connection shall be made by bonding the equipment grounding conductor to the grounded service conductor and the grounding electrode conductor. (B) For Ungrounded Systems. The connection shall be made by bonding the equipment grounding conductor to the grounding electrode conductor. (C) Nongrounding Receptacle Replacement or Branch Circuit Extensions. The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following: (1) Any accessible point on the grounding electrode system as described in 250.50 (2) Any accessible point on the grounding electrode conductor (3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates (4) For grounded systems, the grounded service conductor within the service equipment enclosure (5) For ungrounded systems, the grounding terminal bar within the service equipment enclosure FPN: See 406.3(D) for the use of a ground-fault circuitinterrupting type of receptacle.
Reply to
electrician
I really don't like the use of 'return'. Its a commonly misused word in electrical, used to mean various things and a misnomer in a/c no matter how you apply it.
John
Reply to
John Ray
Some houses turn of the 1900's had all exposed wire. If you had a light switch in the room you were "up town"
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Yes the wire goes from the panel to the load, the breakers would be fine, though a 2 pole common trip would be best and is required. Some ignore this and use the breaker ties.
What is a life or your home worth? Today's world of insurance if what you do causes a fire and it is determined that you violated the accepted code or practices, lets see jail, not paying the claim, and never being able to get insurance again come to mind. So what is it worth to ya. Your questions show a lack of understanding, I suggest the local public library and some reading.
More people die in the home from electricity than any other place.
Reply to
SQLit
Carl, I have never seen a 30 amp circuit used in home electric baseboard use. There is something not correct here with your wire size and or circuit breaker size. 20 amp 240 volt circuits using a 20 amp double pole breaker and number 12 gage wire is the typical way baseboard installs have always been done. I think you would be best served by installing a 10-3 with ground nonmetallic cable (4 wires) from your service box to your new electric dryer position. You will also need a 12-2 with ground nonmetallic cable (3 wires) from your service box to your electric washer. You will need a double pole 30 amp circuit breaker for the electric dryer and a single pole 20 amp circuit breaker for the electric washer. I wired about 100 new homes in the early 1960's and many of them were electric baseboard. back in those days electric cost was nearly the same as oil for home heating. You can email me directly if you like.
Reply to
Dick

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