Art 670.3 Alternate Max Full Load Currents

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lcrane1

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I work for a company that provides equipment that is intended for a broad range of customers. Some use it continuously near its maximum capability. Some use it continuously at far less energy levels. Right now the equipment nameplate is per article 670.3.

For the customers that use the equipment very much below its maximum capability, this is a penalty since they must provide facility support to the equipment according to its nameplate rating.

May I place upon the nameplate a full load current value that is according to how the customer will use the equipment rather than the maximum the product is capable of drawing? The wording of 670.3 seems to imply this is acceptable but I would like to make sure.

Another way of looking at this is that the specifics of "normal conditions of use" vary from customer to customer. Can I change the nameplate accordingly from customer to customer even though the absolute capability of the equipment is the same for each?

Thanks!
L.Crane
 
Re: Art 670.3 Alternate Max Full Load Currents

I've never looked at this section before but it seems pretty clear.

The full-load current shown on the nameplate shall not be less than the sum of the full-load currents required for all motors and other equipment that may be in operation at the same time under normal conditions of use.
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If it were me I might consider adaptations for specific applications if this is a real problem.
 
Re: Art 670.3 Alternate Max Full Load Currents

Physis, Thanks for the reply... but I'm not at clear as to what seems pretty clear to you.

The code says "that may be in operation at the same time". Do you think this is an idication that the highest possible currents should be summed, or the currents that would be present as the equipment is normally used (which may vary from user to user)?

For example, if I make a product that could draw 100Amps but when customer A uses the product, they use it such that it only draws 20Amps and when customer B uses it, it only draws 50Amps, can I have two different nameplates, one showing 20 and one showing 50?
 
Re: Art 670.3 Alternate Max Full Load Currents

What happens if customer A goes belly-up and sells it to customer B? (or some similar scenario)

In any case, the product is still capable of 100A.
 
Re: Art 670.3 Alternate Max Full Load Currents

L., unless there is a way to limit the current use, settable according to expected conditions, then an unexpected overload could increase the current beyond what you anticipate.

Now, if you could lock out unnecessary portions of the equipment according to each customer's needs, then you could effectively provide an honest maximum expected load current rating.
 
Re: Art 670.3 Alternate Max Full Load Currents

I've seen better written sections. But. I still think it's rather straight forward.

I've already posted the revelant portion of it.

Can it use that much?
If so, that's what the nameplate has to say.

I'm not seeing anything that's difficult to interpret.

I apologise if I seem harsh. I don't mean to be.
 
Re: Art 670.3 Alternate Max Full Load Currents

Let me respond more directly.

How much can it draw when it's working correctly?

That's what the nameplate needs to report.

Edit: User to user is meaningless.

Do you think this is an idication that the highest possible currents should be summed,
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Yes.

[ October 25, 2005, 12:16 AM: Message edited by: Physis 2 ]
 
Re: Art 670.3 Alternate Max Full Load Currents

So if I provided fast acting current limitation in my product (say, fuses), then I could limit the nameplate rating to the value of the fuse?

-L.Crane
 
Re: Art 670.3 Alternate Max Full Load Currents

Originally posted by lcrane1:
So if I provided fast acting current limitation in my product (say, fuses), then I could limit the nameplate rating to the value of the fuse?

-L.Crane
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I would think so, but you might have to come up with a way to make overfusing impossible.
 
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