Ordered some 8/2 mc cable for my compressor and welder. The outside diameter measures just a touch over 5/8in. Searched my local lowes for mc connectors. Every thing is either too small or too big. Is there an online option? Maybe an odd size?
8/2 mc cable connectors
- Thread starter caleb90
- Start date
wyliesdiesels
Well-known member
8/2 for a welder? whats the make and model on the welder?
whats the HP rating on the compressor? If its 5hp, #10 MC is fine.
whats the HP rating on the compressor? If its 5hp, #10 MC is fine.
wyliesdiesels
Well-known member
compressor manuals are usually pretty horrible when it comes to electrical specifications... again what is the HP rating on the motor label?
The Mc cable connectors are not glove fit. They are held in by a set screw with something like these as an example.
Were you looking at something else ?
Halex 3/8 in. Flexible Metal Conduit (FMC) Conduit Connector (5-Pack) 20581 - The Home Depot
Get the Halex 3/8 in. Conduit Connectors (5-Pack) 20581, galvanized steel, grounded connect armored cable (Ac) to a steel electrical box from The Home Depot
www.homedepot.com
Were you looking at something else ?
No. Wont fit in 3/8, and 1/2 in is to big. Can screw set screw in all the way, and pull the cable outThe Mc cable connectors are not glove fit. They are held in by a set screw with something like these as an example.
Halex 3/8 in. Flexible Metal Conduit (FMC) Conduit Connector (5-Pack) 20581 - The Home Depot
Get the Halex 3/8 in. Conduit Connectors (5-Pack) 20581, galvanized steel, grounded connect armored cable (Ac) to a steel electrical box from The Home Depotwww.homedepot.com
Were you looking at something else ?
Got home, and the motor reads 5hp 21amps. Im assuming they got there numbers from start up draw. Plus an unheated garage, even with synthetic pump oil it starts slow.. maybe i could have gotten away with 10/2. But the 8/2 was 10bucks more for a 50ft roll.
Can’t say 100% with no pics. I say in these situations, I would cut a small piece and head down to electrical supply store and ask them.
Don’t think you have a special cable, probably just choose a wrong type, make sure it is for the right cable type.
I took a piece with me to lowes. The only thing that fit good was the 1/2 conduit fittings. But they dont have much of a lip to hold the anti short bushing in place
Go to an electrical supply store specific ones not big box stores, if you have those in your area. Besides that, I get wires cheaper with them when I paid cash also. These are the places electrical contractors order from.
Zeke
Well-known member
You didn't say what type of connections. We can only assume into a box KO.
Won't this work for the bigger MC/AC cable?
wyliesdiesels
Well-known member
nope. 21a would be the FLA/run amps
wire for motor circuits is sized by NEC FLC table amps
for 5HP you need #10 THWN or #8/2 NM-b...
10/2 MC wouldve worked fine for both the welder and compressor...
but now youve violated code because the ground wire in 8/2 MC is #10. code requires you to upsize the ground wire when you increase the size of the ungrounded conductors beyond the required size.
since #10 was what was needed, and you increased it to #8, it means the ground wire should also be #8.... but 8/2 MC has a #10 ground...
Jmellc
Well-known member
Only if you are upsizing for voltage drop.
Im not upsizing for voltage drop. Manual calls for a 40 amp breaker on the compressor. 8/2 is 40 amp wire, why i went with it. Could i have run 10/2? Most likely. Welder calls for a 50amp breaker with 10/2 min wire size. So i figure if im buying 8/2 i might well just get enough for both
mike93lx
ALLIANCE MEMBER
I thought the reason is irrelevant, but I'm no sparky and use commercial electric linesmans. Could you provide a code citation for your statement?
alfredeneuman
Well-known member
Unlike AC cable MC cable isn't required to have anti-short bushings.
The mylar jacket is deemed to be sufficient.
I called a manufacturer (AFC) to verify.
rlitman
Well-known member
There are other types of MC connectors than just the normal offset set-screw type. Have you looked at a right-angle connector with the cover that has an angled dimple to engage the armor? That might fit your cable better.
Or there are take-all connectors that are rated for NM as well as MC that have a very wide range of opening size compatibility.
Or there are take-all connectors that are rated for NM as well as MC that have a very wide range of opening size compatibility.
Jmellc
Well-known member
250.122, up to 60 amp Overcurrent device allows #10.
Jmellc
Well-known member
Go to an electrical supply house in your area for connectors. They will have what you need.