Temperature Code for Haz Loc installation

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Temperature Code for Haz Loc installation

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H

HECEngineering

Member
Location
Livonia, Michigan
My electrical inspector always brings up that the temperature code rating must be 80% of the AIT of the gas. I do not see that in the NEC, found some reference to 500.8(c) in the 2011 code book that percentage is not mentioned. Do not see any inferences to ANSI or ISA. Is this a percentage a real requirement or a shirt pocket code? I found it in the CEC but this project is in USA. I want to make sure of the accuracy of such a claim before I make my boss (Cheimical engineer) order the proper motor.
 
H

HECEngineering

Member
Location
Livonia, Michigan
T code

T code

He showed it to me before, I believe it is inferred to with an ANSI/ISA standard. Want to buy the standard for my reference. Just do not see it in the NEC or CEC. I have a current project that requires a third party NRTL inspection, so i am sure I can make them choke it up.


DEW202001 said:
You should ask the inspector to show you where he found his info.


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H

HECEngineering

Member
Location
Livonia, Michigan
jumper

jumper

Sorry if i came a crossed wrong, I fight this every now and then and T codes are one of the most missed critical parameters. Just trying to see if there is a inferred specification/standard that calls it out.

My inspector (from two different NRTL's) both demand T code to be 80% of the AIT. Just trying to find the specification and do due diligence myself.

Thank you responding.


HECEngineering said:
Those are referencing heaters, space heaters and luminaries.
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rbalex

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
If these are NRTL inspectors, they may be dealing with product standards which may be why they are citing ANSI/ISA.

The general NEC rule is Section 500.8(B)(1). Note is says nothing about 80% AIT as a general requirement. Also see Sections 500.8(D)(1) & (2).

There are some specific NEC rules in Section 501.15(A)(1)(1) and sprinkled in Article 501 Part III [starting in Section 501.100] that limit surface temperatures t0 80% AIT.

In general the 80 percent rule applies to Division 2 installations unless the equipment is suitable for Division 1.
 
H

HECEngineering

Member
Location
Livonia, Michigan
80 percent issue on T codes

80 percent issue on T codes

I appreciate everyone's comments, trying to have a sanity check and all the references are making me read the NEC closely once again. I did find the reference to 80% of AIT in article 501.125, I have the 2011 handbook and on page 748 in states the following:

"Totally enclosed motors of the types specified in article 500.125 (a)(2) or (a)(3) shall have no surface with an operating temperature in degrees Celsius in excess of 80 percent of the ignition temperature of the gas or vapor involved." The two mentioned references are talking about pressurized (purge) motors/enclosures and not to motors identified for Class I, Division 1 locations.

PS: I must have my head examined as I love this stuff, thanks again for all your comments.

rbalex said:
If these are NRTL inspectors, they may be dealing with product standards which may be why they are citing ANSI/ISA.

The general NEC rule is Section 500.8(B)(1). Note is says nothing about 80% AIT as a general requirement. Also see Sections 500.8(D)(1) & (2).

There are some specific NEC rules in Section 501.15(A)(1)(1) and sprinkled in Article 501 Part III [starting in Section 501.100] that limit surface temperatures t0 80% AIT.

In general the 80 percent rule applies to Division 2 installations unless the equipment is suitable for Division 1.
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