Ventilation System for CID2

[Dale001289]

Have you ever seen a motor nameplate "marked" for Class I, Division 2? Post a nameplate screen shot or vendor's cut sheet that indicates it's marked.

it’s a separate tag - not on the nameplate itself


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[Dale001289]

Have you ever seen a motor nameplate "marked" for Class I, Division 2? Post a nameplate screen shot or vendor's cut sheet that indicates it's marked.

Just reviewed over 900 induction squirrel cage motors on site - many were not clearly marked for area classification and did not have T ratings
We had to contact Baldor-Reliance, TECO, GE, Siemens and others directly to get their cutsheets showing CI D2 - GPS C and D.
A good indicator —if you see IEEE 841 anywhere on the motor you’re probably good to go.


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[rbalex]

A good indicator —if you see IEEE 841 anywhere on the motor you’re probably good to go.


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Yea, I know. I helped Ralph Haynes write the IEEE paper it was based on. So - how many of those 900 motors had such a marking?

 

[Dale001289]

Yea, I know. I helped Ralph Haynes write the IEEE paper it was based on. So - how many of those 900 motors had such a marking?

Almost all motors supplied by TECO, GE and Siemens were properly marked, but the Baldor-Reliance were not - well over half. We were especially concerned about T ratings. I had to work with the vendor in N Carolina to get paperwork - i.e. letters emails etc confirming they were constructed to meet CID2, C/D with T3.


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[rbalex]

Almost all motors supplied by TECO, GE and Siemens were properly marked, but the Baldor-Reliance were not - well over half. We were especially concerned about T ratings. I had to work with the vendor in N Carolina to get paperwork - i.e. letters emails etc confirming they were constructed to meet CID2, C/D with T3.
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BTW That IEEE 841 mark is only marketing hype, it means nothing. Any NEMA three-phase TEFC is "Suitable" [500.8(A)] for Class I, Division 2. Especially, those with a typical petrochem spec'ed Class B temperature rise which must be marked on the motor per Section 430.7(A)(5). Fifty60 did a fair analysis in Post #10. It is Class II, you really have to worry about.

 

[Dale001289]

BTW That IEEE 841 mark is only marketing hype, it means nothing. Any NEMA three-phase TEFC is "Suitable" [500.8(A)] for Class I, Division 2. Especially, those with a typical petrochem spec'ed Class B temperature rise which must be marked on the motor per Section 430.7(A)(5). Fifty60 did a fair analysis in Post #10. It is Class II, you really have to worry about.

True. But rated temp rise as defined by NEMA, i.e. Class: A=105°C,B=130°C, F=155°C, H=180°C, is not exactly the same as T rating.
To find the expected operating temperature of specific motor you’d take ambient temperature plus temperature rise at rated load. Say you have a TEFC Baldor-Reliance, ECP83665T-4, (3Ph 5Hp, 460V) installed indoors in a process-related, controlled environment @ 21.11C, (70 degrees F) ambient and a temp rise at rated load of 53C (127.4 degrees F); you’d expect only to see 74.11C (197.4 degrees F) total at the motor; this temp would have to be below the motor T rating.

 

[rbalex]

True. But rated temp rise as defined by NEMA, i.e. Class: A=105°C,B=130°C, F=155°C, H=180°C, is not exactly the same as T rating.
To find the expected operating temperature of specific motor you’d take ambient temperature plus temperature rise at rated load. Say you have a TEFC Baldor-Reliance, ECP83665T-4, (3Ph 5Hp, 460V) installed indoors in a process-related, controlled environment @ 21.11C, (70 degrees F) ambient and a temp rise at rated load of 53C (127.4 degrees F); you’d expect only to see 74.11C (197.4 degrees F) total at the motor; this temp would have to be below the motor T rating.

It is however, all that Section 501.125 requires.

 

[Dale001289]

It is however, all that Section 501.125 requires.

T-Codes are the tested CSA temperature for each motor and each motor is different. CSA started the Class and Div T-codes years ago.

 

[rbalex]

T-Codes are the tested CSA temperature for each motor and each motor is different. CSA started the Class and Div T-code yearsback and everyone just started using what they had in place instead of workingup a US version. UL does some similar things they do but not the extentof CSA.

That's a big "Yes, So?". It still isn't an NEC, UL, NEMA or FedOSHA requirement. And standard TEFC motors have been successfully used in Class I, Division 2 since long before either one of us was even in the business.

EDIT Add: And so were open drip-proof for ages.

PPS: It's interesting how the US has become wag-the-dog, like we should adopt every other country's standards, when our own are just fine.

 

[Dale001289]

That's a big "Yes, So?". It still isn't an NEC, UL, NEMA or FedOSHA requirement. And standard TEFC motors have been successfully used in Class I, Division 2 since long before either one of us was even in the business.

EDIT Add: And so were open drip-proof for ages.

PPS: It's interesting how the US has become wag-the-dog, like we should adopt every other country's standards, when our own are just fine.

Not disputing your comment - but just to clarify: A general purpose TEFC motor would not be suitable for CID2. It has to be specified for this usage. (Sources: Siemens, TECO, Baldor-Reliance.)
Went through all this last year during my motor survey on site. We had to replace 8 motors found not to be suited.


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[rbalex]

Not disputing your comment - but just to clarify: A general purpose TEFC motor would not be suitable for CID2. It has to be specified for this usage. (Sources: Siemens, TECO, Baldor-Reliance.)
Went through all this last year during my motor survey on site. We had to replace 8 motors found not to be suited.


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And what do your “sources” cite as their basis? As stated earlier, “It isn’t an NEC, UL, NEMA or FedOSHA requirement.” Basically, it is marketing. Section 501.125(B)(3) says otherwise.

Of course, not all TEFC motors are suitable, but those that are aren’t necessarily special either.

Edit add: BTW IEEE 841 motors are significantly better motors than standard; they just aren’t required.

 

[Dale001289]

And what do your “sources” cite as their basis? As stated earlier, “It isn’t an NEC, UL, NEMA or FedOSHA requirement.” Basically, it is marketing. Section 501.125(B)(3) says otherwise.

As stated earlier in order to qualify for Class I, Division 2, manufacturers must ensure the motor contains no sparking mechanisms. For example, Baldor-Reliance EM3714T-G, is a NEMA, TEFC motor, 10Hp, 460V but it contains an Aegis internal shaft ground and therefore would not be suited for CID2 since the grounding ring represents a sparking source.

https://www.baldor.com/catalog/EM3714T-G
(See sheet 3 and motor drawing at the bottom right title Block, Product Information Pack, PDF.)

 

[GoldDigger]

As stated earlier in order to qualify for Class I, Division 2, manufacturers must ensure the motor contains no sparking mechanisms. For example, Baldor-Reliance EM3714T-G, is a NEMA, TEFC motor, 10Hp, 460V but it contains an Aegis internal shaft ground and therefore would not be suited for CID2 since the grounding ring represents a sparking source.

https://www.baldor.com/catalog/EM3714T-G
(See sheet 3 and motor drawing at the bottom right title Block, Product Information Pack, PDF.)

Semantics, but in this case significant semantics.
The motor needs to be suitable. In the example you give, it does look like that means no ground ring. But that does not require any certification or "specification" from the manufacturer if the difference can be determined by the user from documentation or inspection.

If the manufacturer states that a motor is NOT intended (supported?) for CID2, then use that is prima facie evidence that it is not suitable. If the manufacturer says nothing it does not rule that motor out.

JMO

 

[rbalex]

As stated earlier in order to qualify for Class I, Division 2, manufacturers must ensure the motor contains no sparking mechanisms. For example, Baldor-Reliance EM3714T-G, is a NEMA, TEFC motor, 10Hp, 460V but it contains an Aegis internal shaft ground and therefore would not be suited for CID2 since the grounding ring represents a sparking source.

https://www.baldor.com/catalog/EM3714T-G
(See sheet 3 and motor drawing at the bottom right title Block, Product Information Pack, PDF.)

Ok, but that is already a NEC explicit requirement in 501.125(B)(3).

 

[rbalex]

Semantics, but in this case significant semantics.
The motor needs to be suitable. In the example you give, it does look like that means no ground ring. But that does not require any certification or "specification" from the manufacturer if the difference can be determined by the user from documentation or inspection.

If the manufacturer states that a motor is NOT intended (supported?) for CID2, then use that is prima facie evidence that it is not suitable. If the manufacturer says nothing it does not rule that motor out.

JMO

Well said.

 

[Dale001289]

Ok, but that is already a NEC explicit requirement in 501.125(B)(3).

Correct, but many times things like sparking fans, end plates, ground rings etc get overlooked - in spite of the good intentions of 501.125(B).
If the motor is good for CID2, the manufacturer will invariably state so in their documentation. Well over 90% of TEFC motors already have plastic fans installed as a standard. But one needs to ensure suitability prior to purchasing.

 

[don_resqcapt19]

Correct, but many times things like sparking fans, end plates, ground rings etc get overlooked - in spite of the good intentions of 501.125(B).
If the motor is good for CID2, the manufacturer will invariably state so in their documentation. Well over 90% of TEFC motors already have plastic fans installed as a standard. But one needs to ensure suitability prior to purchasing.

How does an undamaged fan create a spark?

Division 2 does not require that the equipment not be able ignite a flammable atmosphere under ALL possible conditions, just that it not do so under normal operating conditions.

 

[rbalex]

Correct, but many times things like sparking fans, end plates, ground rings etc get overlooked - in spite of the good intentions of 501.125(B).
If the motor is good for CID2, the manufacturer will invariably state so in their documentation. Well over 90% of TEFC motors already have plastic fans installed as a standard. But one needs to ensure suitability prior to purchasing.

Wow, "...in spite of the good intentions of 501.125(B)." That's a pretty unique perspective for a Standard that has been successfully in place and essentially without alteration for well over 50 years. If the items that are "overlooked" were all that great a concern in Class I, Division 2 to CMP14, they would have been specifically called out by now or at least mentioned in a IN. (Why don't you make a PI to that effect for the 2023 NEC)

I just haven't needed a motor manufacturer to hold my hand.

 

[rbalex]

How does an undamaged fan create a spark?

Division 2 does not require that the equipment not be able ignite a flammable atmosphere under ALL possible conditions, just that it not do so under normal operating conditions.

Another well said.

 

[Dale001289]

Wow, "...in spite of the good intentions of 501.125(B)." That's a pretty unique perspective for a Standard that has been successfully in place and essentially without alteration for well over 50 years. If the items that are "overlooked" were all that great a concern in Class I, Division 2 to CMP14, they would have been specifically called out by now or at least mentioned in a IN. (Why don't you make a PI to that effect for the 2023 NEC)

I just haven't needed a motor manufacturer to hold my hand.

Maybe I should write a PI. Article 501.125(B) is very poorly written and continues to be a source of confusion - as witnessed by this thread. I could make it infinitely better by simply adding a few key words. But then again, I've always excelled in logical thinking and creative writing.