New ROMEX into old boxes
#1
11-30-14, 05:41 PM
New ROMEX into old boxes
OK so I fished all new Romex for my light circuits replacing the old cloth romex. The existing boxes are metal with (actual diameter 5/8") knockouts and a double clamp. How do you secure new wire in these boxes? I am concerned the wire will be clamped onto the sharp knock out lip. also some clamps don't hold the wire tight. Do they make something so that these old boxes can be used or must they be replaced? Below is a picture any suggestions or experience welcome. Thank You.
#3
11-30-14, 06:28 PM
I already fished all the wires not anticipating having this problem. So fighting wires is done. If I have to replace boxes I will, but want to try and avoid it so I don't mess up the plaster walls.
#5
11-30-14, 07:00 PM
I tried the push in connectors but the knock out is not a standard size measures 5/8 where the 1/2 Knock outs measure 7/8. I could not find smaller than the standard 1/2 push in connectors.
#7
11-30-14, 07:36 PM
Thanks for all the replys. Pcboss do you know if they sell the clamps to replace or add to that style box? Also when clamped some do not actually clamp the wire they diameter is too big. While others do clamp it but seems to clamp on the knock out lip which I think could puncture the Romex. Is this ok? Am I over thinking it?
#10
12-01-14, 12:11 AM
I like Ray's suggestion...1/2" push in connectors measure what? 7/8"? Are you sure...are you measuring the narrowest part?
The ones we use are thinner than Ray's pic. Also, you need a ground screw.
How are those boxes mounted? I don't see a screw inside the pic. I would replace them, as plastic boxes are cheap, and come with plastic clamps. I've gotten lucky and replaced boxes without the need for mudding...Hand sawzall with narrow metal blade can chop screws attaching box.
The ones we use are thinner than Ray's pic. Also, you need a ground screw.
How are those boxes mounted? I don't see a screw inside the pic. I would replace them, as plastic boxes are cheap, and come with plastic clamps. I've gotten lucky and replaced boxes without the need for mudding...Hand sawzall with narrow metal blade can chop screws attaching box.
#11
12-01-14, 03:59 AM
Yes I bought the smallest push ins and tried no luck hole is too small. The ground is easily added. I believe they are mounted with tab that are nailed to the studs. Starting to look like I'll be taking the multimaster to them and trying to swap for plastic ones. Thanks
#12
12-01-14, 06:34 AM
Member
Yes I bought the smallest push ins and tried no luck hole is too small.
#13
12-01-14, 06:46 AM
Forum Topic Moderator
If you replace the boxes look for the Smartbox style that screws to the stud from the inside of the box. Much more secure.
#14
12-01-14, 07:16 AM
The boxes are marked GE sp7074. The house was built in 1948 had original version of cloth romex. With using them I'm concerned with the clamp pushing the romex on the knock out edge, is this not an issue or the same way modern ones clamp also?
#15
12-01-14, 07:23 AM
Member
The house was built in 1948 had original version of cloth romex. With using them I'm concerned with the clamp pushing the romex on the knock out edge, is this not an issue or the same way modern ones clamp also?
pcboss
If you replace the boxes look for the Smartbox style that screws to the stud from the inside of the box. Much more secure.
If you replace the boxes look for the Smartbox style that screws to the stud from the inside of the box. Much more secure.
#16
12-01-14, 07:43 AM
The boxes are marked GE sp7074. The house was built in 1948 had original version of cloth romex. With using them I'm concerned with the clamp pushing the romex on the knock out edge, is this not an issue or the same way modern ones clamp also?
#17
12-01-14, 07:49 AM
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The old box looks like it's Bakelite. I doubt if the edges of knockouts are sharp enough to cut into sheathing. I would use the existing clamps and just gently tighten them against cable. It doesn't take much pressure to provide the required strain relief.
#18
12-01-14, 10:55 AM
Forum Topic Moderator
Brian, that is a black steel box. It predates Bakelite by quite a few years. One of the giveaways is the chamfer on the back of the box.
