A question for the group - 15amp a/c on a 30 amp circuit

Hello, My house, bulit in the 1950's, has a separate 250v, 30amp circuit that goes directly to the a/c plug. and it uses standard amo carthridges
My old air cond. went doa aftder decades of use. So this was the first time I had to but a new window unit.
I bought a smaller (18,000 btu) because the graphic symbol for the plug looked the same as the old plug. but after opening the box I see that the plug is alot smaller. The new unit is a 230v 15 amp. that requirs 15 time-delay carthridges
So m questions are:
1) can I use 15 amp time delay carthridges in the old 30 amp box
2) Can I change the plug outlet to a 15 amp type
3) if I have the change the old 30 amp box, must I change the wires as well?
Thank you.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 29 Jun 2003, jlc wrote:

If they're the same physical size, sure.

-Somebody- can, if you have the know-how to do that, then sure you can. Call an electrician if you don't.

No. The wires will have extra capacity above what is being used, and that is perfectly safe and legal. If you were trying to do it the other way -- use a wire too small for the load -- then yes, you would need to change it.

No problem. Pay no attention to the leg-humping pets of mine who migt show up and critique my answer, they have this little obsession thing going on, they're harmless.
TP
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
He's right. The fuses protect the wiring, not the appliance. Although if you put a 15 amp outlet replacing the 30A outlet and leave the 30A fuses in the box, the outlet is not protected, and neither is the cord to the air conditioner.
It would be best to figure out a way to reduce the fuse size if you can't put 15A fuses in the fuse holder (which is conceivable, I guess--I'm not that familiar with cartridge fuses). As long as the circuit is fused at 15A, everything is safe.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

in
This is Turtle.
Hey are we talking about the regular 3 inch long 60 amp fuse holder box and can get a reduce to put say a 15 in it. I can get a 40 to put in the large boxes but not 30 amps down. You say they have a fuse like a 15 amp that will fit the bigger box fuse holder. Let me know about that.
TURTLE
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

can't
in
This is Turtle.
I called my Electric supply house this morning and checked on the fuse holder from the big to the small and they have them. Now i feel like a dumb ass all these years having to change the guts or box out when I went to smaller amp fuses. I haven't done very few at all but it still gets me not to know something like that.
Thank you there for the info.
TURTLE
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

1
or
fuse
or
the
If
time
You dont think it might have something to do with venting a gas heater with PVC, or using copper pipe as a fuse would it???? Its not like Tom hasnt done that, and claimed it safe..
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You've already got a bunch of good advice, the only thing I have not seen mentioned is attaching the #10 AWG to the 15 A outlet might not be so easy. I suppose you can pigtail some #14 off the #10 to get onto the terminals.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is Turtle.
# 10-2 romex will fit but you have to watch to keep it straight when putting it on there. Make the wire go all the way around the terminal before tightening it. It is a pain to do but it will work. Also the back push in for the wire will not work.
Now if you have #10-2 with ground typeTHHN or the likes. It is a breeze and use clamp on forks and just pop them on there. I'm just wishful thinking here , sorry.
TURTLE
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

A pigtail off the #10 is probably OK, but it's my understanding that the screw connectors on a common 15A receptacle are not rated for use with #10awg (or larger) wire. In fact, it may very well be a code violation in some municipalities.
Again, this is just my understanding. Perhaps one of the electricians here can correct me on this if I'm wrong.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 30 Jun 2003, Banister Stairwell wrote:

Just a slight oversight on your part, I think: The "pigtail" wire -will- be #14, exactly what should go to a 15A outlet. Each pigtail (the one for neutral and the one for hot) will have in the wire nut: 2 X #10 feed in / feed out and 1 X #14 wired to the device
HTH.
TP
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is Turtle.
Tom , if you was doing this kind of work. You would know a #10-2 with ground will fit on a 15 amp recepital any day of the week. I hook them up all the time for temperary service with #10-2 with ground for 150 to 200 feet runs of power service for electric tools used on the commercial buildings and i'm really under sizing the wire with #10-2 with ground. The #12 and the #14 will have a power draw down going that far on 15 amps of service. Up to 50 feet you can use #12-2 with ground and Up to 80 feet you can use #10-2 with gound and then at 200 feet it calls for #6-2 with ground. #6-2 with ground will not fit on the 15 amp recpitcal. You will have to drop down to atleast #10 .
Tom , Take your electric toy box out and hook a #10-2 with ground up on a 15 amp plug or recepitical and get back with us. I know it will be hard for you to do but try it you might like it.
TURTLE
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
My thanks to those who replied to my question.
1) The new 15 amp fuses were the same sizes as the old 30 amp so they fit fine.
2) It was a bear but I was able to twist the wires around the screws on the new outlet plug
3) turned the main power on and my a/c started right up!
I'm happy (and cool) now
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is Turtle.
More Power to you. keep the Amps flowing.
TURTLE
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.