4v shane
Well-known member
Connector on my air compressor! the unit requires 40 amps and my outlet is 50 using 8 guage SJOOW both the black and white leads have these connecters on them and have the black/brownish melting going on.
suggestions?
Whats causing this to happen?
- Thread starter 4v shane
- Start date
Connector on my air compressor! the unit requires 40 amps and my outlet is 50 using 8 guage SJOOW both the black and white leads have these connecters on them and have the black/brownish melting going on.
suggestions?
Charles (in GA)
Well-known member
Yes, its burning up, thats what.
As I noted in another thread, the more connections, terminals, crimps, etc, you introduce into a circuit, the more problems you will have. Most likely, those terminals are not rated for the amperage they are having to carry, or they were not properly crimped.
If this is a permanent installation without a plug on the cord, you need to eliminate the cord and go with WIRE, such as large romex or THHN in a flexible conduit. The connections at the pressure switch, motor starter, etc, are designed for WIRE, and not the fine stranded stuff used in cord, which someone circumvented by installing the terminal ends on it.
It is not acceptable per code to use cord (fine stranded wires) in terminal connections such as the connections on a pressure switch or a motor starter.
Charles
As I noted in another thread, the more connections, terminals, crimps, etc, you introduce into a circuit, the more problems you will have. Most likely, those terminals are not rated for the amperage they are having to carry, or they were not properly crimped.
If this is a permanent installation without a plug on the cord, you need to eliminate the cord and go with WIRE, such as large romex or THHN in a flexible conduit. The connections at the pressure switch, motor starter, etc, are designed for WIRE, and not the fine stranded stuff used in cord, which someone circumvented by installing the terminal ends on it.
It is not acceptable per code to use cord (fine stranded wires) in terminal connections such as the connections on a pressure switch or a motor starter.
Charles
nehog
Well-known member
What kind of terminal is it? Most crimp on terminals have a current rating, and if that is a red one (looks red) then 40 amps is way too much. If it is yellow, then 40 amps is probably too much also, though most yellow connectors are rated for about 40 amps. Also what brand terminal is it? Cheap imported ones are not going to handle the power.
awdblazer
Well-known member
should be using a ring terminal also
Gary S
Well-known member
40 amp wire with a 10 amp terminal.
Speedy Petey
Well-known member
What makes you say it is a "10 amp terminal"??
Gary S
Well-known member
The physical size of it tells you it can't handle much more than that without slowly failing. Look at the mass of the wire and compare to the mass of the connector. That terminal looks like a great fusable link for a #8 wire.
rburke65
Well-known member
We need a picture! But, it is just getting too hot and is starting to burn.
Speedy Petey
Well-known member
Seriously??? That is how you are determining this is a "10 amp terminal"??
Speedy Petey
Well-known member
Funny, I am not seeing ANY amperage rating for terminals, just wire size. And if a terminal is rated to accept #10 wire it stands to reason that it is rated for at least 30A.
porcupine73
Well-known member
Hm it looks like it's getting hot where the wire connects to the terminal. Resistance in the connection is critical to be kept low, especially as the current increases, because P=I*I*R, so it gets far worse as the current increases. If the connection is dissipating say even 10 watts what you've really got yourself there is a nice little soldering iron.
Discovered that my pressure switch contacts have also welded themselves to one another............. Hardwire this thing in? now my question is .....Obviously i have a SJOOW cable on this plugged into a 220 outlet.... Now can I just run hardwire into the box and connect to the existing wire? what gauge would you guys recommend to do so if possible?
Gary S
Well-known member
And, it still burns up. How do you explain that?
porcupine73
Well-known member
Resistance where the wire connects to the terminal, from the pics it seems to look like that's where it's 'burning'.
ddawg16
Well-known member
That crimp connector is not designed for that kind of duty. No where near enough surface area to handle a constant current like that.
You need the right sized ring terminal if your going to use a crimp connection....and you need the right crimp tool.
Chances are your pressure switch is welding because it's not designed to switch 40 amps. Most are designed for low current....you use the pres switch to energize a motor starter that is designed for the high currents.
And....if you were using a real motor starter....it would have the proper terminals to connect your line and motor to.....you wouldn't need crimp terminals.
Look on your pressure switch...I bet it says 10A or 10A max.
This is a good example of how fires start.
You need the right sized ring terminal if your going to use a crimp connection....and you need the right crimp tool.
Chances are your pressure switch is welding because it's not designed to switch 40 amps. Most are designed for low current....you use the pres switch to energize a motor starter that is designed for the high currents.
And....if you were using a real motor starter....it would have the proper terminals to connect your line and motor to.....you wouldn't need crimp terminals.
Look on your pressure switch...I bet it says 10A or 10A max.
This is a good example of how fires start.
Speedy Petey
Well-known member
Ummmm...poor termination.
I'd have to say at least 50% of crimp terminals I see are done poorly.
I agree..I believe even the heavy duty pressure switches only have an amp range up to 30 amps.
Charles (in GA)
Well-known member
At one time I had something flagged, cannot find it now. Basically it said that terminals on devices had to be listed for cord wire for it to be acceptable to use cord. Since cord wire is so fine stranded, it crushes and compresses and quite often is difficult to get it to stay under the screw or the terminal or connection, to where the terminal can properly grip the cord. Basically it said that if it isn't listed for cord, you cannot use cord.
Charles
Flexible cords are not to be used in place of perm. wiring so cord between a pressure switch & the motor or starter is not compliant anyway.
See if you can come across it as it's of some importance to me. I have never had any problems with running it to starters and motor control equipment and have never had any connection problems.
Maybe, but I use it on ALL of my machines as they are all currently plug attached. I'm also going to use it for the drops from my busway. Of course I'm of the "school" of thought that the NEC code ENDS at the outlet.
William...