Class 1 Div 2 Alternators

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Gen Ex

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Hi trying to get some clarity on the requirements for alternators operating in Class 1 Div 2

For Zone 2 generators In Europe we use
Ex n Alternators
Built to comply with BS 5000 part 16. and EN50021: 1999 Certified Type EEx nA II T3 For use in Zone two Hazardous Areas
Automatic Voltage Regulator (AVR) is installed within an EEx d Zone 2 enclosure.

However keep coming up against IP56 TEFC alternators being used, however the manufacturers will not offer these as certificated for Haz Area use ?

My thoughts are that you should still use Ex product.

Rating range typically 10 - 150 kVA

Can anyone help clarify ??

Thanks
Jim
 
Hi There

No on this particular project we are exporting to the Asia Pacific market, where the specifications tend to move between Eurpoean ATEX Zone 2 and USA Class 1 Div 2, in this instance they are working to Class 1 Div 2.

It has been suggested that an IP56 Alternator will comply, but my experience is that the Alternator manufacturers will not provide a certificate of complaince for use in Hazardous Area.

So I guess I am looking to see what is done in the USA when you place a diesel generator with an alternator in a Hazardous Area.?

Thanks
Jim
 
I?m referring to the 2005 NEC, but with regard to motors, generators and other rotating electrical machinery the content is essentially the same in previous editions.

Section 501.125(B) is the principal text. In short, there is no requirement to identify rotating electrical equipment specifically for Division 2 applications. This pretty much gives three-phase induction equipment a ?free-pass,? since most insulation systems require machine designs with maximum temperature rises levels below those permissible for the location?s ?T-rating.? (See 500.8(B)(4) and it's primary rules)

The primary cautions are therefore that auxiliary items such as switches or in-line overcurrent devices be identified for Class I, Division 1. This would also apply to the engine driver?s electrical components.
 
Class 1 Div 2 Generators

Class 1 Div 2 Generators

Hi Bob

Thanks for the reply

Is there any requirement from an IP perspective

In the UK we are required to use IP56 termination boxes on the alternator cable terminations.

The specificaitons I am receiving for Class 1 Div 2 Generators ask for

Engine with flame protection package (See www.pyroban.com)
Which includes items such as
Air intake shut of valve
Flame Trap
Exhaust Gas cooling to below 200 Deg
Spark Arrestor
EEx d Control Panel (Circuit Breaker)
EEx e instruments. ( Control Module )

IP56 Alternator, or Ex n Alternator

I often feel that the specifications grow in content as people move from contract to contract and in some cases they are excessive so just trying to be confident in stating there is no requirement for X or Y such as alternator and Ex d Panels?

Would appreciate any further advice

Thanks
Jim
 
Bob

Forgot to add, with regard to the IP perspective, could we use a standard alternator with say IP23 rating given the temp rise and insulation class were in spec?

Jim
 
The ?basic? NEC rule for applying ?Zone? rated equipment in ?Division? classified locations is 501.5:
General The general rules of this Code shall apply to the electric wiring and equipment in locations classified as Class I in 500.5.
Exception: As modified by this article.
Equipment listed and marked in accordance with 505.9(C)(2) for use in Class I, Zone 0, 1, or 2 locations shall be permitted in Class I, Division 2 locations for the same gas and with a suitable temperature class. Equipment listed and marked in accordance with 505.9(C)(2) for use in Class I, Zone 0 locations shall be permitted in Class I, Division 1 or Division 2 locations for the same gas and with a suitable temperature class.
Click to expand...
The problem is the phrase ??listed and marked in accordance with 505.9(C)(2)?? The NEC uses ?AEx? rather than ?EEx? markings. They are marked to a similar, but nevertheless different set of Standards. In addition, the gas groupings are not entirely compatible, though close enough for most applications. The ?T-ratings? are generally compatible for insulation systems.

Having said all that, a package suitably marked and applicable for CENELEC (or one of the EU Norms) Zone 2 should be acceptable in a Class I, Division 2 location.

As an aside, we don?t typically use the ?IP? designation for enclosures.
 
Thanks again for the reply.

Sorry if I am being a bit repetitive, I guess the bottom line question is

Can I use a standard product alternator in a Class 1 Div 2 area.

If a standard alternator is not acceptable what is the minimum standard that can be used.

Thanks
Jim
 
Gen Ex said:
Thanks again for the reply.
Click to expand...
Gen Ex said:
Sorry if I am being a bit repetitive, I guess the bottom line question is

Can I use a standard product alternator in a Class 1 Div 2 area.

If a standard alternator is not acceptable what is the minimum standard that can be used.

Thanks
Jim
Click to expand...

I may sound like I?m beginning to hedge.

The following is extracted from Section 501.125(B):

In Class I, Division 2 locations, the installation of open or nonexplosionproof enclosed motors, such as squirrel-cage induction motors without brushes, switching mechanisms, or similar arc-producing devices that are not identified for use in a Class I, Division 2 location, shall be permitted.
Click to expand...
It does set a philosophical basis, but it refers specifically to motors. There is no conclusive statement that applies directly to other rotating electrical equipment. The above permits what most would call a ?standard? motor in Division 2. However, the rest of Section 501.125(B) indicates restrictions that relate to the auxiliary / ancillary equipment that may also be used.

At that point you need someone more familiar with all the specifics of the ?package? and not simply the alternator.
 
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