Class1 Div 2 Transformer

[1937chevy]

Fuel pier with electrical room has a step down transformer 480/208/120 dry type. Is this the proper equipment. What I read 501.100(B) Class 1, Div 2 location, transformers and capacitors shall comply with 450.21 through 450.27. The transformer is 30KVA dry type which falls under 450.21(A). If I am reding this right there seems to be nothing wrong with this appliction.

 

[rbalex]

Occasionally, instrumentation on larger transformers may need attention in Class I, Division 2 and all transformers should be reviewed for their ?T-Class? although it is rarely a problem in most applications. See Section 500.8. While Subsection 500.8(B)(6)(a) indicates no special marking is required, Subsection 500.8(A)(1) still requires they be ?identified? as suitable for the location.

 

[jflynn]

Occasionally, instrumentation on larger transformers may need attention in Class I, Division 2 and all transformers should be reviewed for their ?T-Class? although it is rarely a problem in most applications. See Section 500.8. While Subsection 500.8(B)(6)(a) indicates no special marking is required, Subsection 500.8(A)(1) still requires they be ?identified? as suitable for the location.

Hi- Bob,
We have a job that was just classified by the engineer class 1 div 2, we had panels & a 112kva transx in the classified area.He wants us to now install the panels on the other side of the classified area-seperated by a 2hr fire rated wall.Can we still locate the transx in the classified area?it would be about 12-15'AFF.This is a car dealership with a service bay area.

 

[rbalex]

...Can we still locate the transx in the classified area?it would be about 12-15'AFF...

Yes.

Since I don?t know the details, I assume the electrical area classification is based on Article 511 and the area classification is actually fairly limited.

In any case, depending on the installation, you may have some boundary sealing issues and a few wiring method considerations, but there is still nothing to prohibit the transformer itself from being in the Division 2 location.

The ?T-Classification? should be part of the documentation and my comments in my previous post still apply. It?s very unlikely, ?T-Class? will be a problem.

 

[jflynn]

Yes.

Since I don?t know the details, I assume the electrical area classification is based on Article 511 and the area classification is actually fairly limited.

In any case, depending on the installation, you may have some boundary sealing issues and a few wiring method considerations, but there is still nothing to prohibit the transformer itself from being in the Division 2 location.

Correct the classification is based on 511,what are some of the wiring methods that need considerations?we dont do alot of this work,our intent was to stay 24"AFF with our installs-we are being told the ceiling is vented and not classified,so we are assuming we can install standard wiring methods in the ceiling,thanks

 

[rbalex]

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...
Correct the classification is based on 511,what are some of the wiring methods that need considerations?we dont do alot of this work,our intent was to stay 24"AFF with our installs-we are being told the ceiling is vented and not classified,so we are assuming we can install standard wiring methods in the ceiling,thanks

You need to review Section 511.7. There are some restrictions on wiring and equipment above classified locations. They don?t apply to the transformer, but you need to be aware of them.