Lighting, Light Fixtures, Ceiling and Exhaust Fans - lighting/ recommended wires
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hdriderjvl
03-21-07, 11:19 AM
I just purchased some new wall mount lights and inside it says to make sure to use a supply wire temp rated at a certian temp. What I have now is a medcine cabinate with a light and will be changing over to two lights. so i will be installing some new wire from a junction box. Will this be fine my house is about sixty years old and has all old wires in it. Why do are they calling for this wire? I have done quite a bit of electrical work and this is the first time I have run into any thing like this.
Thanks for any help.
B.
Thanks for any help.
B.
racraft
03-21-07, 11:35 AM
New wire rated for 90 degrees C. This is designated by the "B" in the designation (NM-B, UF-B). Older wire is only rated for 60 degrees C.
If your wiring is 60 years old, you have two problems. 60 year old cable is not rated for 90 degrees and would be a fire hazard to connect directly to the fixture. However, it can be connect further down the line and new cable run from a junction box. Remember that the junction box MUST remain permanently
accessible.
The other problem is that the cable is likely ungrounded. Code does not allow extending ungrounded circuits, and in a bathroom you certainly do not want an ungrounded light fixture that someone can reach, especially near the sink.
I recommend a new circuit from the main panel, and bringing the entire bathroom up to code. Depending on the scope of your project, this may be required anyway.
If your wiring is 60 years old, you have two problems. 60 year old cable is not rated for 90 degrees and would be a fire hazard to connect directly to the fixture. However, it can be connect further down the line and new cable run from a junction box. Remember that the junction box MUST remain permanently
accessible.
The other problem is that the cable is likely ungrounded. Code does not allow extending ungrounded circuits, and in a bathroom you certainly do not want an ungrounded light fixture that someone can reach, especially near the sink.
I recommend a new circuit from the main panel, and bringing the entire bathroom up to code. Depending on the scope of your project, this may be required anyway.
hdriderjvl
03-21-07, 11:50 AM
Is this going to be the same case for all fixtures? I have also heard that with this age home containing metallic sheathed wires going back to the breaker box along with metal outlet boxes acts as a ground as the metal sheathing takes place of the bare copper wire. Is this true? If so as long as I use a metal box for the junction box I should be fine. Correct? I have not moved in to this house yet so I can not exactly investigate everything yet I am just trying to get prepared in advance.
Thanks,
B.
Thanks,
B.
John Nelson
03-21-07, 02:02 PM
Not all fixtures require 90-degree wire, but many do.
Using a metal box does not allow you to use a 90-degree fixture on old wire. You have to join old wire to new wire somewhere, and then join new wire to the fixture, at least a foot away from the old wire. As previously noted, all splices must be in permanently accessible junction boxes.
If I were you, I wouldn't go planning a lot of electrical changes to a house this old without replacing circuit wiring first. The easiest thing to do is to run brand new circuits, with all new wiring, for your new electrical needs. If the electrical box has not yet been updated, this task should come first. These are the type of limitations you have to accept when living in an older house if you want to live there safely.
Using a metal box does not allow you to use a 90-degree fixture on old wire. You have to join old wire to new wire somewhere, and then join new wire to the fixture, at least a foot away from the old wire. As previously noted, all splices must be in permanently accessible junction boxes.
If I were you, I wouldn't go planning a lot of electrical changes to a house this old without replacing circuit wiring first. The easiest thing to do is to run brand new circuits, with all new wiring, for your new electrical needs. If the electrical box has not yet been updated, this task should come first. These are the type of limitations you have to accept when living in an older house if you want to live there safely.