explosion proof inverter!

try mine safety equipment, and the term "intrinsically safe " +mine gives this:-

http://www.google.com/search?hl=en&q=%22intrinsically+safe%22+%2Bmine&btnG=Search

drill among these to make your inquiries/

LOL! there is no such thing as 'intrinsically safe" when it comes to inverters, unless you want an inverter for something that only requires 8VDC!

By inverters, I suppose you mean a Variable Frequency Drive. It is nearly impossible to put a VFD of any significant size into an explosion proof enclosure, they put out too much heat for the enclosure to dissipate. The largest I have ever seen is 10HP (7.5kW) in a box that was 36 inches by 60 inches by 20 inches, essentially the largest Ex. Proof box you can get. They were relying on the convection capability of the aluminum of the Ex.P enclosure walls, but because they are solid, not finned (in order to contain an explosion), they do not conduct heat as well as is necessary, hence the extreme surface area. Above 10HP you can sometimes get away with what is called a "purged" enclosure, but that requires a significant source of instrument grade compressed air and an EMO system to kill power to the enclosure should the purge system fail to maintain a certain pressure. That makes purged systems very very expensive, but sometimes that is the only option.

well, they do make many pieces conform to the intrinsically safe standard, usually by such hermetic methods with periodic inspections to make sure it is still sealed. some reference occur

drill here

http://www.google.com/search?hl=en&q=%27intrinsically+safe%22+%2B%22mine+safety+standard%22&btnG=Google+Search

As I understand it intrinsic safety is achieved by barriers (electrical, in the supply cable) outside the hazardous area, which limit the amount of energy into the hazardous area to below that needed to cause ignition. Then an explosion cannot occur.

As JRaef pointed out, it's only applicable to things like instruments, which use very low power. There's no such thing as, say an intrinsically safe 90kW motor! But motor can be explosion-proof.

Codey

try searching internet for either "hazardous location" + inverter or try "Class 1" + inverter

Have a look at the Ampcontrol website.

If a piece of equipment is classed as explosion proof [Ex d], then the method of protection refers to the enclosure and its ability to contain and withstand an internal explosion without communicating any incendive event to any flammable atmosphere outside of the enclosure. This concept will impose limits upon the configuration and operation of the inverter were it to be located in a hazardous area; one could not operate and test it with the cover removed, for example. It might be better to use a different style of inverter that can be located in a safe area and connect to the motor in the hazardous area using a longer cable.

Usually, hazardous area certification for a variable speed installation needs to look at the inverter and the motor as a combination, otherwise there is a risk of spurious frequencies being generated in an inverter appearing as heat in the windings of a motor and the motor's surface temperature exceeding its temperature classification. With this scenario, although the individual components may have individual certification, the overall system may be operating outside it.

The safe area inverter/hazardous area motor installation outlined above would still require certification as a complete system.

National requirements for hazardous area testing and certification vary slightly, though there has been effort to harmonise these across Europe.

The requirements for mines are different from the requirements for surface applications, and in a coal mine the installation will need to be certified as safe against the presence of highly explosive dusts as well as explosive gases. Coal dust is in this category.