Proper melting alloy

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kwired said:
My reply was assuming he was using the correct selection table for the application (sounds like it was sent with the controller - so the chances of it being correct table are pretty high, but can still be factors that may dictate using a different table). Using the correct table for the application will result in compliance with NEC requirements

If using the correct table for the application and the current value needed is not in the table, you basically need a different controller with a different possible current range for the overload elements available to it.

There are many tables in the Digest, you need to look at selection information at the beginning of that section to determine what table you need to use for your application. Same overload element has different amp ratings depending on conditions at the point of use.
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The OP is answering a homework problem.
This has little to do with an actual application.
 
jim dungar said:
The OP is answering a homework problem.
This has little to do with an actual application.
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Right. My coworkers have all said 'in real life, it would work'. But we aren't dealing with real life, unfortunately. Most of my coworkers were dumbfounded by how poorly everything was worded and set up, so how do you think I feel? :?
 
StitzieJ said:
Trying to read the NEC book makes me want to bash my head into a wall.
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Don't make it more complicated that you need to.
First the answer is not really in the NEC. You found what you needed to know, that the NEC considers the motor to be protected even if the overcurrent protection is as large as 125% FLA.

Many decades ago (back in 1930's or so) Square D started just matching the starter and its thermal unit range directly to 100% motor FLA while ignoring most other information..
Some other manufacturers, like maybe everyone else, uses different methods for selecting their products, so having the proper tables become essential.
 
Smart $ said:
So ultimately he must choose a different product? :D
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NOPE! I actually just got off the phone with Square D. They did have additional options for that starter for lower currents. It's a rare item so the lead time is crazy, but it exists so I'm going with that! Thanks for the feedback everyone!

P.S. And if anyone is looking into this topic, THE MODEL NUMBER FROM SQUARE D IS A.47 FOR USING THE 2510FG1 STARTER WHEN THE MOTOR'S FLC IS AT .4 AMPS.

Thanks again!

-John
 
Hmph... in my opinion, 0.01A was not worth the phone call...
As pointed out earlier, the tolerances on those types of devices is +-10% at best anyway, so worrying about 0.01A in a range of .37 to .45 was somewhat pointless.

But you do what you do...
 
StitzieJ said:
NOPE! I actually just got off the phone with Square D. They did have additional options for that starter for lower currents. It's a rare item so the lead time is crazy, but it exists so I'm going with that! Thanks for the feedback everyone!
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There is nothing wrong with a phone call. You have learned(?) that the Digest does not list all the possible information.
 
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