Gas Detection Control Panel

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Your question is vague.

I guess it depends, will the installation be under the NEC or another code?

Does the AHJ require equipment to have a TRTL certification regardless of what the applicable codes states?
 
clarifications...
Is a 500.7(K) Combustible Gas Detection System required to be installed:

1. in accordance with Chapter 3 Wiring Methods and Materials; or,
2. in accordance with ARTICLE 760 Fire Alarm Systems?
 
the only gas detection system we ever installed was for a gas utility, and it was required to be FM approved, and subject to approval by the utility, DOT/DOE, and the public service commission. I would adhere precisely to the specs, direction from the ahj, or qualify the items precisely in order not to hang yourself. I would say that UL approval would be the very minimum that would be required for any gas detection system IMO.
 
Merry Christmas

Okay, listed gas detection equipment is required, no problem.

Does the control panel need to be listed or certified?

Could a generic PLC be used to recieve the gas level information and have the PLC perform the shutdown criteria? Or does that approval fall on the AHJ?

I have too much Eggnog sloshing around my belly....
 
To be or not to be? To list or not to list? To certify or not to certify?

Depends on they type of facility, company standards, and the acceptable risk.

I'd say owner's risk managment program should decide. Google SIS, SIL, LOPA for some background that can help managment decide. Don't let them say "Bill said it was OK".

Be aware of new NFPA 72 (2010) Mass Notification Systems (formerly fire alarm code) now covers gas detection and coordination with fire alarm system.

Good Luck, Happy Hunting and Happy New Year!

BobG
 
We install gas detection systems for LNG and NG plants frequently. We normally bring all the gas signals into the process PLC for whatever action might be required. the signals or a combination output are retransmitted to a fire panel if it exists.

Int the past, there was no mention of connecting gas detection equipment to fire panels in NFPA 72, except that they would be considered auxiliary equipment and their installation and connection needs to meet all fire detection requirements.

This becomes more complicated and potentially costlier when you need to consider the amount of battery backup capacity. We have asked this question of several fire alarm system designers without a completely satisfactory answer, so the process PLC connection serves our purposes well.

I greatly appreciate the mention of the new requirements in 2010 NFPA 72, as it now seems that gas detection will no longer be considered "auxiliary". Have to do a little reading on this.
 
I only made a cursory review of Sections 14.4 and 17.10; but I don't see gas detection as a mandatory requirement in NFPA 72-2010. It definitely isn't what is envisioned in any of the applications recognized in NEC Section 500.7(K)
 
"500.7(K)(1), (K)(2), or (K)(3) shall be permitted.
The type of detection equipment, its listing, installation location(s), alarm and shutdown criteria, and calibration frequency shall be documented when combustible gas detectors are used as a protection technique."

What did the writers of this section mean by "its listing" ?

The detector itself? or the entire system?
 
Within context of the NEC, gas detection is only permitted to be used as protection technique for three very specific applications [500.7(K)(1), (K)(2), or (K)(3)]. Again within context and since the 2008 NEC edition, each of the permitted applications specifies listing requirements for the detection equipment.
 
Please forgive me if I am being obtuse; but other than the detectors, what combustible gas detection equipment specific for Class I, Division 1 (or Division 2 as the case may be) for the appropriate material group, and for the detection of the specific gas or vapor to be encountered do you envision within the limits of the permitted applications?
 
I am wrestling with if the equipment associated with the control of the shutdown criteria and alarm functions need a listing. The analogous equipment in a fire alarm system is the certified fire alarm control panel.
 
Toxic gas sensing

Toxic gas sensing

On several of the "micro-chip" plants I worked on in the "90's" all had gas sensing equipment, either "MDA" sniffer style, or "Gastech" electronic sensors. All were connected to a PLC arrangement which controlled the permissible exposure limit (PEL) alarms for evacuation of the workers (two levels, yellow =1/2 PEL and blue = PEL). All of this was mandated by the Fire Marshall. None to my knowledge was connected to the fire alarm panels that were present.
 
Natfuelbilll said:
I am wrestling with if the equipment associated with the control of the shutdown criteria and alarm functions need a listing. The analogous equipment in a fire alarm system is the certified fire alarm control panel.
Click to expand...
I guess we can try this again. Which of the three permitted applications are you attempting to use: 500.7(K)(1) Inadequate Ventilation, (K)(2), Interior of a Building (where the interior does not contain a source) or (K)(3) Interior of a Control Panel?

Which of those applications would require listing "...the equipment associated with the control of the shutdown criteria and alarm functions..." beyond the detectors themselves - which were already clearly required to be listed?
The type of detection equipment, its listing, installation location(s), alarm and shutdown criteria, and calibration frequency shall be documented when combustible gas detectors are used as a protection technique."(bold yours, underline mine)
Click to expand...
is simply an extension of the "properly documented" requirements in 500.4(A) to establish the basis of a classified location installation.

Note add: Other equipment may have listing requirements, but not because of 500.6(K)
 
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