spark ignited engines in classified areas

[gascomp]

I am a new member to this site and have a question that often comes up on oil and gas production sites. When a compressor is located on one of these sites it is often in what is classed as a Class 1, Group D, Div II location which calls for elimination of potential sparking sources. Is it possible to locate a spark ignited gas engine in a classified area and still comply with the applicable US codes? This has also been a problem in locating compressors on offshore platforms where the entire platform is classified. In the past, ignition systems with shielded secondary wiring were often used but I'm not sure that this meets the code requirements. On most of the new engines the ignition coil connects directly to the spark plug so there is really no secondary, high voltage wiring. What is considered acceptable practice when a compressor with a spark ignited engine is located in a classified area?

On many production sites, available space may be limited which prevents the compressor from being located a long distance from any potential sources of explosive mixture.

Appreciate any comments or direction on this.
Thanks
Don

 

[catserveng]

Many gas engine manufacturers can provide engines that can operate in these areas. Newer technology puts the ignition transformer under the valve cover, with an extender connecting it to the spark plug instead of a lead wire.

Most of the systems I worked on were listed by CSA, you can check with their website.

Hope that helps.

 

[dcasto]

You can get shielded systems from the coil out all the way to the plug and the plug its self.. Altronic and Stitt are good places to start.

 

[gascomp]

Part of my question is "do shielded ignition systems fully comply with Class 1, Grp D, DivII area classifications"? Reason for asking is that I have seen photos of gas engines with shielded ignitions operating at night where you can clearly see a "corona" or blue haze around the secondary wiring that could be considered a source of ignition.

 

[dcasto]

I like to see those pictures and how they were taken. You call it a corona? if there was enough electrical energy leaking to make corona, the cylinder would not be firing.

http://www.ataengine.com/pdf/ataengine-altronic.pdf

read about their compliance with Class I div II.

 

[bcs5274]

class I div II ignition is not uncommon , i have many compressors old and new with shielded ignition running that i take care of, i have units from the 60's up to brand new with shielded ignition on all makes and models of engines,

engines in this enviroment have more cost associated with the ignition system, plugs for instance run $45 ea. on average, all the wiring from the magneto to the coils is shielded and the coils can be on the plugs or mounted on a rail, plugs are available for both. newer caterpillar 3500 series engines are currently mounting the coils under the valve cover, they are good engines but the cost is higher for these components compared to externally mounted components and of course you can only get parts from cat for these newer 3500 series engines