Flame Proof Electrical Motor

Set fire to them. Any one that doesn't burn is flame proof.

Or is there some other info you didn't mention?

I believe "explosion proof" is a rating that some motors have. I'm not a motor expert but "flame proof" is not a rating that I have heard.

For explosion proof the answer is easy, look at the data sheet.

It will say "Ex (d)", "Ex (e)" or "Ex (n)" on the nameplate. At least it will in Europe, not sure whether this applies worldwide. These apply to varying degrees of protection, allowing the motor to be used in hazardous zones of varying ratings. You'll need to look into it to find more details.

With ref to Flame Proof and explosion proof, as far as I know they're equivalent. But neither refers to fires or explosions outside the motor, which the motor might be built to withstand. It means if a flammable gas (or dust) gets into the motor, and is ignited by an electric or friction spark, the resulting explosion is contained and cannot ignite the external flammable mixture. E.g. there might be long passages for the flame to escape, so it has cooled to below the ignition temperature before getting out.

Ex e is "increased safety", not explosion-protected.

Ex n is "non-incendive", not explosion protected.

The operating condition that any electric motor is designed to work in can only be verified by contacting the motor manufacturer. Usually the web site will provide sufficient information. There are common regional motor label designations that can mislead a novice. An E or EX on a label can mean a motor is explosion proof rated if the motor manufacturer uses that convention. Another manufacturer can also mean extended wear bearings have been installed.

It is critical to understand that explosion proof does not mean that the motor can work in an explosion. It means that it can work in an explosive atmosphere, if properly configured, without igniting an explosion.

If your design requires a motor working in a flame (flame proof) and not near a flame, then I recommend changing your design. The high temperature electrical insulation wiring needed to power this motor will not be easy to implement.

Pick one from here

Flame Proof Motors Manufacturers & Suppliers

Unless it's the one equipped with flame arrestors.

By the letters FP enclosed within a heptagon.

Now how long will it take for the Chinese to produce such an item?

They probably already do produce them. They probably produce both high quality and inferior versions. I'm fairly certain that you cannot tell the difference until it is to late.

They are producing them, for quite along time.

http://www.alibaba.com/countrysearch/CN/flameproof_motors.html

Including the symbol to which I was referring?

No, none of them use that symbol. The Chinese are incapable of producing any kind of recognizable symbol.

Do read the article in Wikipedia on the topic, entitled "electrical safety in potentially explosive atmospheres.

Identifying one is easy. It will have the label "Ex d" or "EEx d" on the rating plate, be 'built like a tank', and access to any area where electrical conductors can be exposed will be accessible by using a special tool and not a regular open-ended spanner or a screwdriver. It will have an Ex d or EEx d gland as well, if correctly installed; any Ex d motor that doesn't have a compatible gland is not explosion-protected and if located in a potentially explosive atmoshpere is an explosion waiting to happen.

Selecting, installing or maintaining one are tasks for someone who is specially trained. Make sure that suitable training is on-board before attempting any of this.

Hello

The most widely followed world standards are 1)N.E.C.(National Electric Code),followed in America and American continent 2)I.E.C.(International Electro-technical Commission), followed in most other countries including India, 3)C.S.A (Canadian Standards Association) followed in Canada and 4)CENELEC (European Committee For Electro-technical Standards), for European countries

Among these four N.E.C. and I.E.C. standards are more common than the other two because of their use in most countries.

The basic question why special type motors for hazardous areas?

It is common knowledge that oil and gas or petro-chemical industries, deal with storage, processing and manufacturing of petroleum and petro chemical substances which lead to formation of flammable gases and vapors and when combined with oxygen can form an explosive mixture.

Presence of these explosive mixture cannot be eliminated totally due to the process involved in these industries

When this explosive mixture, concentrated in the atmosphere to Lower Explosive Limit, is accidentally ignited, it leads to fire and consequent explosion.

Hence the only way to minimize fire or explosion is to select the special type enclosures, motors and devices designed to contain ignition in hazardous areas.

And electrical motors, cables, starters and other switch gear are the ones that are very much prone to short circuits, failures and are the main sources of ignition leading to fire.

And that is why understanding, the gas groups (Group I,II and III), Zones (0,1 and 2) and suitable equipment for a specific zone, is necessary for the safety officers and electrical engineers in these industries

9 specially designed devices or enclosures are there for use in hazardous areas

And there are four types of protection techniques involved with these special devices and enclosures

The nine special type of devices or enclosures are

1) Type d-Flame Proof, 2)Type e-increased safety, 3)Type i- intrinsic safety, 4)Type m - encapsulated, 5) Type n- non incendiary or non sparking, 6)Type o- oil immersed

7)Type p- purged/pressurized 8)Type q- sand or powder filled 9) Special protection

The four protection techniques are

1) Designed to prevent any means of ignition arising; Examples ; Ex e and Ex n

2) Designed to limit the ignition energy of the circuit; Examples: Ex i

3) Designed to isolate the flammable mixture reaching the source of ignition

Examples; 1) Ex m 2) Ex 0 and 3) Ex p

4) Designed to prevent the source of ignition propagating to the external flammable atmosphere Examples 1) Ex d, 2) Ex q

Hence it can be understood that these specially designed devices and enclosures work under different techniques for different hazardous zones (0, 1 and 2)

Before going to see what is Flame Proof understanding zones is must

1) Zone 0- Most highly dangerous hazardous area in an installation or to elaborate it, it is the zone in which the presence of flammable gas is present for more than 1000 hours in a year with concentration of 10% or more than the L.E.L.

2) Zone 1- Moderately highly dangerous area or to elaborate it, it is the zone in which the presence of flammable gas is more than 10 hours but less than 1000 hours in a year with 1% to 10% L.E.L concentration

3) zone 2- A dangerous area in which the concentration is between 0.1% and 1% of L.E.L for 10 hours or less in a year

Hence an enclosure designed for a particular zone, say zone 2, cannot be used in zone 1 or 0

And an enclosure for zone 1 cannot be used in zone 0 (But can be used in zone 2, because the degree of danger is lesser). FLP is designed for zone 1 and hence not suitable for zone 0

And only Type m and Type i are meant to be used in zone o and these can be used in zone 1 and 2 as well

As far as FLP motors are concerned they are made of cast iron or aluminium alloy because of their ductile (or elastic) property which helps to contain or withstand the explosion within the enclosure

And the surface of the flame path is machined and the air gap between the terminal box and the cover is designed in such a way that the flame cannot propagate or transmit via the flame path that is via the flanges, spindles and other jointed surfaces, and cannot ignite the flammable external atmosphere

I hope this gives the basics of equipment on hazardous areas and suggestions are most welcome