I see, now what you are doing. This is very different to my first impression, my experience is with feeding flat contiuous strip into a press or cut off. The accel problem over 1 g is more of a mechanical thing than drive tunning, in that the drive/motor will do it but it kind of leaves a trail...
Don't use a photocell for registration. Use a "press" clear signal (prox or limit) that is set at the point where the press is just open enough to get the material through so you get a head start on the feed. Most mechanical presses have CAM switches on them to provide this signal which can be...
GGOSS,There is another statement in the code, that says if other devices are specifically marked with maximums that they override the selection, soit should be considered as you say.
Do others agree with aolalde ? In that the overload is going to protect the cable so the 1AWG should be...
I am looking for a litle guidance about somthing that is driving me crazy whilst trying to size a motor conductor/fuse combination (Using NEC Code).
I have a 75HP AC motor (regular NEMA frame 1.15 SF)with seperate O/L protection so the fuse is SC and GF protection only and I want Type 1...
With respect to e-stop do this and you will be safe. Position the contactor on the line side of the drive, and screw the communications, if its e-stop its e-stop and after an e-stop you can expect to follow certain procedures to get the machine going again, and normally if the drive is the fault...
I have encountered this with customers in the past who managed to destroy a number of PLC processors before their big boss came down and strictly forbid them to weld on the machine whilst under power (though I guess component damage is still possible with the power off but it seemed to do the...
How does the existing e-stop on the system work ? I would have thought you want the vibration switch in the e-stop circuit one way or another to stop the rest of the machine asap ? It sounds like you are adding this switch after you have already had a problem with the machine and i have to...
Thanks guys I like that web site too their electrical protection handbook is good to (and free) or mine was anyway but i am not sure how old it is.
I think I maybe leaning towards breakers now, however another thing i noticed was that you have to watch the rating with respect to a fault on just...
I think I am being overcautious when you look at the size of the transformer required to produce that sort of fault level, but then agin this type of equipment does go into steel plants etc. So big supplies are possible.
Thanks for your thoughts i feel more confident after this chat!
Snoogie
In North America very large supply capability equipment can be hooked up to your panel. My concern is not with the PLC /Drives pulling these sort of values but if we have a ground fault on the buss bars or cabling inside the panel then potentially the full KA fault current of the supply system...
Does anyone have any thoughts / experience with using circuit breaker type disconnects over fused switches?
I have used both in the past but always worry about fault levels when using cricuit breakers as it is often very difficult to estimate actual fault currents.
My applications are typically...
I have exactly the same problem with the same drive on a much larger system (I have two 300hp Drives) I have tried everything, adding line reactors load reactors, monitoring the supply line with chart recorders the works to avail. It still is a problem today. The customer just has to run the...
Its fine to use incremental encoders as you intend. The accuracy is not an issue as it will be as good as absolute with respect to the encoder funtions. However what you should do is put one limit / prox switch on each axis which can be used used as a permanent known position such that if any...
You know i think you are right I have had the CSA come and sticker panels here in the past and looking back at the report sheets they all have 5KA as the rating and i could never figure out why everything was 5KA !
Thanks guys i think the only practical answer is to leave it off.
Snoogie
When adding a name plate to a control panel with the voltage / current rating etc.. How should the KA of the PANEL be rated for the name plate (ie NOT how is the ka of the supply deterimined). Should it be based on the lowest KA rated device that is connected directly to the incomming supply...
