Switchgear: Metal-Clad vs Metal-Enclosed
Switchgear: Metal-Clad vs Metal-Enclosed
(OP)
Ok, no dramatic way to ask, so I'll just jump right in.
I have in front of me as I write copies of IEEE C37.20.3 and C37.20.2
Outside of some minor differences in ratings and the rather lengthy definition atributed to MC gear, I can not find a significant difference between the 2. So, is there any truly significant difference here? Is it just a matter of manufacturing quality (ie. MC switchgear is made to a higher standard)? Or have I completely missed the boat?
I have in front of me as I write copies of IEEE C37.20.3 and C37.20.2
Outside of some minor differences in ratings and the rather lengthy definition atributed to MC gear, I can not find a significant difference between the 2. So, is there any truly significant difference here? Is it just a matter of manufacturing quality (ie. MC switchgear is made to a higher standard)? Or have I completely missed the boat?






RE: Switchgear: Metal-Clad vs Metal-Enclosed
RE: Switchgear: Metal-Clad vs Metal-Enclosed
In short, there is a difference in construction and testing standards. And it is significant.
For one metal clad switchgear is not supposed to get deformed due to an internal fault, the metal enclosed one could.
Rafiq Bulsara
http://www.srengineersct.com
RE: Switchgear: Metal-Clad vs Metal-Enclosed
RE: Switchgear: Metal-Clad vs Metal-Enclosed
Alan
----
"It's always fun to do the impossible." - Walt Disney
RE: Switchgear: Metal-Clad vs Metal-Enclosed
RE: Switchgear: Metal-Clad vs Metal-Enclosed
RE: Switchgear: Metal-Clad vs Metal-Enclosed
For ANSI visit www.ansi.org, for UL www.ul.com
Do you want to build it or specify it?
For specifying ask the mfrs, such as GE, ABB, Square D, Eaton, Siemens or visit their websites. For getting to know what is in the standards you need to purchase them, especially ANSI and UL. UL has some requirements but not all, they are more concerned with testing to the standards claimed by the mfrs, safety and some of their own requirements.
NEC does not have requirement for construction of equipment.
Rafiq Bulsara
http://www.srengineersct.com
RE: Switchgear: Metal-Clad vs Metal-Enclosed
So taking that to a practical example, imagine a Pump Lifting Station with 6 big pumps being fed by MEIS gear. A fault happens in one pump and causes significant damage to the controller, which in turn damages adjacent controllers. If the pumps were all necessary for the lifting operation and cannot develop enough head with even one missing, then the fact that one fault took out multiple units is contextually irrelevant. However if these were water supply pumps necessary to maintain pressure that may be needed for fire fighting, having one fault take out multiple units could be disastrous, justifying the use of Metal Clad gear.
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: Switchgear: Metal-Clad vs Metal-Enclosed
Most ANSI and IEC switchgear is metalclad.
RE: Switchgear: Metal-Clad vs Metal-Enclosed
We may have different definitions of metalclad switchgear. In the U.S., I think ANSI C37.20.3 metal enclosed gear is much more common than metalclad (because it is less expensive). Metalclad is typically seen where high fault duty, high reliability, frequent operation and/or special controls are needed.
I agree the jraef, except that I would replace "will contain a fault within one cubicle" with "will be more likely to contain a fault within one cubicle".
Alan
----
"It's always fun to do the impossible." - Walt Disney