heavy plug and recepts?

The heaviest thing my All Phase catalog has for plug and recepts in 3 wire is 6 50R. Most larger machines I see are hard wired to a disconnect instead of plugged (as are my own). Is this the case normally or there heavier ones availiable?

 

Depends on what type of plug end you're looking for.

In a straight blade, the biggest is a 50 Amp
In a Twist lock, the biggest is also a 50 Amp
In a Pin and Sleeve you can get up to a 200Amp configuration

So, the short answer is, yes there are larger cord connectors available. But, if you've ever priced a pin and sleeve set, you'd understand why most machines are hard wired to the disconnect. (Last set I purchased was about $350 for the pair)

 

Yup, thats what I thought. Just wanted to make sure I had it straight,, thanks.

 

And for welding equipment you cannot use the plug as the disconnect. A disconnect switch is required. The only advantage of the plug becomes portability.

 

Why could you not use a plug as a disconnect? Most small machines are recept and plug wired to a breaker in the panel. No seperate disconnect. As far as I knew a plug could be a legal service disconnect for most equipment. (certainly could be wrong though)

 

most plug are useally horsepower rated and amparages but for larger plugs some case it will listed for make and break set up. but really check the manufacter for lastet listing for plugs and it will tell the hp and amprages and please do note that some plugs are not made for load and break set up. simuair rules do apply to fused or nonfused disconnet switches. for most commercal area i deal with it i useally put a disconnet switch right next to the plug because the load factor is pretty high with 480 volt system.


i did try to find the nec code my old code book did explain plenty for 15 and 20 amp plugs but not much for large industrail types

art. 422-22 and art 440-63 that is in 96 code book but i still find the answer for 02 verison as soon i get the answer i will post it here or john or cselectric can post it here also


merci marc

 

Cause the code section for welding equipment says specifically a switch must be used. If no one posts the exact call out I will put it up. Code is not at the office today.

 

NEC 2002

for ARC Welders

630.13 Disconnecting Means. A disconnecting means shall be provided in the supply circuit for each arc welder that is not equipped with a disconnect mounted as an integral part of the welder.
The disconnecting means shall be a switch or circuit breaker, and its rating shall not be less than that necessary to accomodate overcurrent protection as specified under 630.12.

for Resistance Welders

630.33 Disconnecting Means. A switch or circuit breaker shall be provided by which each resistance welder and its control equipment can be disconnected from the supply circuit. The ampere rating of this disconnecting means shall not be less than the supply conductor ampacity determined in accordance with 630.31. The supply circuit switch shall be permitted as the welder disconnecting means where the circuit supplies only one welder.

 

The other avenue of relief would be if the main switch on the unit opens both conductors for a 240 V unit. You only need to open the single hot on a 120 V of course.

 

Yes, the switches in these machines is 2 pole, now that still has nothing to do with a serevice disconnect which a plug would give. The way I am reading it and this could be wrong, but the breaker in the panel could be the disconnecting means also.??? Now, it could be that if the panel it comes from isnt visable from the machine there could be requirement for another disc. So, if breaker is turned off and the plug is disconnected it would certainly comply with the intent here. So, if the machine has a 2 pole switch, which the one in question does, that eleminates the need for a seperate disc? As I read 630.13, that seperate disc req only applies if the machine doesnt have the switch. if it does then a cord and plug would certainly be suitable for a service disc. Once it is unplugged its irrelevent.

 

For a resistance welder the breaker in the panel can be the disconnect as stated in 630.33. This permission to use the overcurrent protection for the branch circuit as the disconnect is not given for arc welders.
The interpretation I have always been given is that unless the welder has an integral switch that opens all current carrying conductors, a separate disconnect must be provided. Using the cord as the disconnect would require it to be rated at the breaker value (which can be 200% of the I1max) instead of just I1max.

 

Most modern welding machines do have a double pole switch, at least the home or small shop style machines (any of them on single phase anyway). In the old days there were a lot of owner fabricated machines that may not have. The modern ones ave the recomended recept rated fairly close to the breaker, I have one that recommends 60 brkr and comes with a 50 plug. Maybe some large industrial machines do not have big switches in them? Its been a while since I have been around them and didnt pay all that much attn to the primary wiring when I was. Seems there was a disc on big 6 packs where they fed all 6 with one cable, that must be where this applies. I assume that the NEMA rating for these small machines requires the type of switch to meet the code requirements for disc.