# Motor service factor question



## MDShunk (Jan 7, 2007)

It sounds like a lot of your company's problems can be solved by re-educating your coworker with a 2x4 across the head.


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## Wirenuting (Sep 12, 2010)

MDShunk said:


> It sounds like a lot of your company's problems can be solved by re-educating your coworker with a 2x4 across the head.


How I wish. 

Here's a picture just because everyone likes pictures.


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## MDShunk (Jan 7, 2007)

About a 30 horse Leeson?


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## Wirenuting (Sep 12, 2010)

MDShunk said:


> About a 30 horse Leeson?


25 HP Dayton that I'm sitting on. 
I just used this one as an example.


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## MDShunk (Jan 7, 2007)

A Dayton motor could be anything. I think that there's at least 2 or 3 people OEM for Grainger's motors.


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## Wirenuting (Sep 12, 2010)

MDShunk said:


> A Dayton motor could be anything. I think that there's at least 2 or 3 people OEM for Grainger's motors.


This motor runs like a champ and is protected correctly. 
The OP question was can you use the SF amperage to select your O/L's. 
A co-worker keeps doing it.


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## MDShunk (Jan 7, 2007)

Wirenuting said:


> The OP question was can you use the SF amperage to select your O/L's.
> A co-worker keeps doing it.


Oh, you wanted an answer to your original question? :laughing: nope.


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## kwired (Dec 20, 2009)

I know if you look at square D thermal overload charts for NEMA starters you must multiply FLA x .90 if the service factor is 1.0. Instructions say to use the values on the chart for SF of 1.15 or 1.25.


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## Wirenuting (Sep 12, 2010)

MDShunk said:


> Oh, you wanted an answer to your original question? :laughing: nope.


Right, I wanted someone to agree with me and give me an idea what to do with him. Also a code reference if possible as I didn't find the answer. 
The 2x4 answer is perfect. Now all I gotta do is figure out what kind of wood.


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## kwired (Dec 20, 2009)

Show your co worker 430.32(A)(1) it corresponds to what I put in previous post. Most thermal element charts are for 1.15 SF or higher and many people do not adjust for motors that are less than 1.15 they just go by values on chart.


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## Wirenuting (Sep 12, 2010)

kwired said:


> Show your co worker 430.32(A)(1) it corresponds to what I put in previous post. Most thermal element charts are for 1.15 SF or higher and many people do not adjust for motors that are less than 1.15 they just go by values on chart.


So that and 430.32(C) is the answer. 
430.43 answers the auto reseting of the electronic O/L's. 
I thank you very much.


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## Jlarson (Jun 28, 2009)

I gotta agree with the 2x4 idea.


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## MDShunk (Jan 7, 2007)

Jlarson said:


> I gotta agree with the 2x4 idea.


When I heard that he just wings IEC starters up the whole way snd sets them to auto reset, I said to myself, "Hey- I know that guy". :laughing:


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## Wirenuting (Sep 12, 2010)

MDShunk said:


> When I heard that he just wings IEC starters up the whole way snd sets them to auto reset, I said to myself, "Hey- I know that guy". :laughing:


Do you want him?
He took today off to remodel his bosses basement.

btw, his boss is an insulator & mine is an old machinist.


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## John Valdes (May 17, 2007)

MDShunk said:


> A Dayton motor could be anything. I think that there's at least 2 or 3 people OEM for Grainger's motors.


Dayton is Dayton, GE is GE and Marathon is Marathon. Last I checked these three are sold and marketed as shown above. These are the three I know Grainger sells in this market. I belive GE is the OEM for Dayton.



kwired said:


> I know if you look at square D thermal overload charts for NEMA starters you must multiply FLA x .90 if the service factor is 1.0. Instructions say to use the values on the chart for SF of 1.15 or 1.25.


NEMA heaters are not adjustable and for the end users sanity they do allow a small percentage of SF when sizing heaters. At least, thats my guess.
I never allow for service factor when sizing or setting overload relays and NEMA heaters. I use FLA every single time.
NEMA is not the one that has to replace the burned up motor. We do.


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## kwired (Dec 20, 2009)

John Valdes said:


> ..
> NEMA heaters are not adjustable and for the end users sanity they do allow a small percentage of SF when sizing heaters. At least, thats my guess.
> I never allow for service factor when sizing or setting overload relays and NEMA heaters. I use FLA every single time.
> NEMA is not the one that has to replace the burned up motor. We do.


 
NEMA heater units are not adjustable, but they are replacable with a unit with a different trip point. 

I have seen heaters replaced by unqualified people before just like I have seen adjustable overloads turned all the way up, Just like I have seen 30 amp plug fuses installed on 15 amp circuits. If there is a way to increase a trip setting people will do so if they are having problems with tripping. 

I have also seen heaters replaced with 12AWG solid copper - no more tripping.


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## Wirenuting (Sep 12, 2010)

kwired said:


> NEMA heater units are not adjustable, but they are replacable with a unit with a different trip point.
> 
> I have seen heaters replaced by unqualified people before just like I have seen adjustable overloads turned all the way up, Just like I have seen 30 amp plug fuses installed on 15 amp circuits. If there is a way to increase a trip setting people will do so if they are having problems with tripping.
> 
> I have also seen heaters replaced with 12AWG solid copper - no more tripping.


You can't stop stupid.


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## Jlarson (Jun 28, 2009)

MDShunk said:


> When I heard that he just wings IEC starters up the whole way snd sets them to auto reset, I said to myself, "Hey- I know that guy". :laughing:


I know lots and lots of those guys, mostly water operators, they do the same to breakers, if it's adjustable they will crank it up.


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## LARMGUY (Aug 22, 2010)

Wirenuting said:


> Right, I wanted someone to agree with me and give me an idea what to do with him. Also a code reference if possible as I didn't find the answer.
> The 2x4 answer is perfect. Now all I gotta do is figure out what kind of wood.


 
White pine is always good but for this instance I would use pressure treated.


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## lefleuron (May 22, 2010)

Somebody help me here.

I thought if the motor was service factor 1.0 you had to size heaters no more then name plate FLA.

If the name plate was 1.15- 1.25 AND you had tripping problems, then you could size heaters to no more then 120% of FLA.

Am I confused on that?


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## kwired (Dec 20, 2009)

lefleuron said:


> Somebody help me here.
> 
> I thought if the motor was service factor 1.0 you had to size heaters no more then name plate FLA.
> 
> ...


Read the information from the manufacturer of the heaters you are using.

As I mentioned previously square D says right on the selection table that the table is for motors with 1.15 -1.25 SF and is a trip rating of 125% of full load current. It also says to multiply full load current by .90 then use that value to select from the chart for motors with a service factor less than 1.15. 

I am mostly familiar with Square D but would guess that others are similar.


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## erics37 (May 7, 2009)

Wirenuting said:


> Right, I wanted someone to agree with me and give me an idea what to do with him. Also a code reference if possible as I didn't find the answer.
> The 2x4 answer is perfect. Now all I gotta do is figure out what kind of wood.





LARMGUY said:


> White pine is always good but for this instance I would use pressure treated.


Can't go wrong with Douglas Fir. Hell there's a Doug Fir in my neighbor's yard that wants to blow over onto my roof in the next wind storm. I can chop it down and mill up some 2x4s for your entire crew if you want. For a fee :thumbup:


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## Wirenuting (Sep 12, 2010)

erics37 said:


> Can't go wrong with Douglas Fir. Hell there's a Doug Fir in my neighbor's yard that wants to blow over onto my roof in the next wind storm. I can chop it down and mill up some 2x4s for your entire crew if you want. For a fee :thumbup:


Thank you. 
But as a federal employee I can not except a gift as large as that. The Dollar value to outfit the whole crew exceeds what is allowed. 

That being said,, one four foot piece for me would be perfect. And I know who I would want to use it with. LoL


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## Wirenuting (Sep 12, 2010)

erics37 said:


> Can't go wrong with Douglas Fir. Hell there's a Doug Fir in my neighbor's yard that wants to blow over onto my roof in the next wind storm. I can chop it down and mill up some 2x4s for your entire crew if you want. For a fee :thumbup:


I'm sorry. I didn't read your last statement. 
"For a fee."
That sounds great. Please provide a stock number and a dollar value. Make it in the 6 digit range and I'll buy it.


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## John Valdes (May 17, 2007)

lefleuron said:


> Somebody help me here.
> 
> I thought if the motor was service factor 1.0 you had to size heaters no more then name plate FLA.
> 
> ...


Tripping problems should be addressed as over current issues. You do not correct over current with overloads and heaters. You find out what is causing the over current and correct it. I do not run motors in their service factors unless its an emergency. Using FLA for sizing protects motors. We replace them, they don't.



kwired said:


> Read the information from the manufacturer of the heaters you are using.


I agree to an extent. But I can tell you if I had a 16 FLA motor, there is no way I am installing 20 amp heaters, (125%) regardless of what Square D says. I am installing 16 amp or as close to 16 amp I can find.

Much of my thinking on this subject is from years of buying, maintaining and replacing fried motors and equipment. Its not all text book to me. Some of it is old school thinking.


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## kwired (Dec 20, 2009)

John Valdes said:


> Tripping problems should be addressed as over current issues. You do not correct over current with overloads and heaters. You find out what is causing the over current and correct it. I do not run motors in their service factors unless its an emergency. Using FLA for sizing protects motors. We replace them, they don't.
> 
> 
> 
> ...


And if your 16 amp motor is normally loaded to 13 amps there is nothing wrong with providing protection at 13 or slightly above if you wish to catch an overload in the driven load sooner than if protecting at the code minimum of 20. 

The application, who maintains it and how they maintain it may dictate or change how you choose to protect it.


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