NAME PLATE READING and Understanding.

[Fordean]

Curious,


A 3 phase Shrink Wrap Heater. @ 208 volt. Has a 30 amp stamped on the Tag. It came with a 30 amp 3 pole Cord end. Implying a 30 amp 3 phase circuit. Should't this be a 40 amp circuit. Due to Breaker 80 percent rule.


Question here is does the Name Plate Inscription 30A. Does this state 30 amps it DRAWS (making this a need for 40 amp wiring) or Recommends 30 amp Circuit.

Always wundered on this.

 

[MarineTech]

For me, to better bring this into context, would it be possible to get the flexible cord info?

Thanks.

 

[ron]

Since the heater will not stay on all the time (it will cycle to keep temperature), it wouldn't be continuous load (>3 hours).

If that is true, then a 30A circuit should be okay.

 

[Strathead]

Curious,


A 3 phase Shrink Wrap Heater. @ 208 volt. Has a 30 amp stamped on the Tag. It came with a 30 amp 3 pole Cord end. Implying a 30 amp 3 phase circuit. Should't this be a 40 amp circuit. Due to Breaker 80 percent rule.


Question here is does the Name Plate Inscription 30A. Does this state 30 amps it DRAWS (making this a need for 40 amp wiring) or Recommends 30 amp Circuit.

Always wundered on this.

You may find your own answer if you try to find the code reference for the "80% rule".

 

[Fordean]

Since the heater will not stay on all the time (it will cycle to keep temperature), it wouldn't be continuous load (>3 hours).

If that is true, then a 30A circuit should be okay.

Heater in the manufacturing, Tend to start and leave on all day due to its Delay into coming up to temp. They leave on probably longer then 3 hours.

 

[Fordean]

:blink:

You may find your own answer if you try to find the code reference for the "80% rule".

Going to look to see what your implying. Dont think I ever read that article fully. If you refer to the book. Give me article. So I know you know your stuff

 

[Strathead]

:blink:

Going to look to see what your implying. Don't think I ever read that article fully. If you refer to the book. Give me article. So I know you know your stuff

Well my statement was somewhat of a trick but, as someone else wrote above continuous loads is a clue. There is no 80% rule. I will narrow it down for you to Article 200 of the NEC. You will find the answer, or more accurately the lack of an answer to the allowable amperage through a 30 amp receptacle in the same article only a page past the above section. You will find the actual code requirements often referred to as the "80% rule" also. I am not being coy or condescending. I treat my guys the same way. Article 200 is one of the articles you should read and reread over and over. All the way through. Along with 100-400. You will be a better Journeyman for it.

What I am trying to do is get you to look. We can do the work for you, but you will probably learn three or four other things by doing the work yourself.

 

[suemarkp]

Also, what is the description of the nameplate current? Some heating devices have an MCA value, which already includes the 125% factor for heater branch circuits (you'll also see MCA on HVAC compressors where it also covers the 125% factor for those). Motor FLA and RLA has just the "normal" amp draw. If it just says amps, then you have to assume 30A is the worst case load of this item when all parts are active. Whether it is continuous or not is machine specific. Just because it is on all the time doesn't mean its continuous -- it has to be on for 3 hours or more at full amp load. If it cycles (which most heaters do), it is most likely not continuous.

 

[infinity]

Curious,


A 3 phase Shrink Wrap Heater. @ 208 volt. Has a 30 amp stamped on the Tag. It came with a 30 amp 3 pole Cord end. Implying a 30 amp 3 phase circuit. Should't this be a 40 amp circuit. Due to Breaker 80 percent rule.


Question here is does the Name Plate Inscription 30A. Does this state 30 amps it DRAWS (making this a need for 40 amp wiring) or Recommends 30 amp Circuit.

Always wundered on this.

Take a look at these two sections:

II. Branch-Circuit Ratings
210.19 Conductors ? Minimum Ampacity and Size.
(A) Branch Circuits Not More Than 600 Volts.
(1) General. Branch-circuit conductors shall have an am-
pacity not less than the maximum load to be served. Where
a branch circuit supplies continuous loads or any combina-
tion of continuous and noncontinuous loads, the minimum
branch-circuit conductor size, before the application of any
adjustment or correction factors, shall have an allowable am-
pacity not less than the noncontinuous load plus 125 percent
of the continuous load

210.23 Permissible Loads. In no case shall the load ex-
ceed the branch-circuit ampere rating. An individual branch
circuit shall be permitted to supply any load for which it is
rated. A branch circuit supplying two or more outlets or
receptacles shall supply only the loads specified according
to its size as specified in 210.23(A) through (D) and as
summarized in 210.24 and Table 210.24.

 

[Strathead]

Take a look at these two sections:

Shoot Rob, I was trying to get him to find the sections on his own.:slaphead: Never know what else a person will learn.

 

[Fordean]

Take a look at these two sections:

Thanks. I love how they brain twist you with the lingo



Thanks for post.!

 

[Fordean]

Shoot Rob, I was trying to get him to find the sections on his own.:slaphead: Never know what else a person will learn.

I Know code book pretty well. But I remember about ten years ago. Finding the Derating of non continous loads to a percentage. I should have dipped right into code book. Sometimes I like to Post things that may help others as well.. Guess we (I) get lazier when approaching my 50!


Thanks for response. Understand what you were doing !

 

[Strathead]

I Know code book pretty well. But I remember about ten years ago. Finding the Derating of non continous loads to a percentage. I should have dipped right into code book. Sometimes I like to Post things that may help others as well.. Guess we (I) get lazier when approaching my 50!


Thanks for response. Understand what you were doing !

54 and so do I. One of the things I do here is read code sections. It helps me to stay on top of things. Sometimes it can save me from embarrassment. Other times I forget. I got busted here recently about grounded wires. Oops :dunce:!

A few years ago I did a lot of work on a commercial garage design build. Knew that Article 511 like the back of my hand. I recently got a set of plans to bid, and thought the EE had really messed up. Just before I sent an RFI, I opened the 2011 code book for a quick look. To my surprise the entire section was different with no indication of editing. I had to then pick up the 2008 where I found that the entire section had been rewritten. We just don't know what we know!:?

 

[BPoindexter]

What is the KW rating of the heaters? Could possibly fall under 670 in which case the rating stamped on it is the rating of the OCPD supplying it. 670.3(A)(2)

 

[Fordean]

What is the KW rating of the heaters? Could possibly fall under 670 in which case the rating stamped on it is the rating of the OCPD supplying it. 670.3(A)(2)

Not sure if it had a KW. I will Relook. I usually Logged all job specs in my computer so I can reference. (Phone Pictures) Work Great.