Switchgear and switchboards

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Strathead

Senior Member
National and international standards define the manner in which electric circuits of LV installations must be realized, and the capabilities and limitations of the various switching devices which are collectively referred to as switchgear. from http://www.electrical-installation.org/enwiki/The_basic_functions_of_LV_switchgear

In an electric power system, switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. from Wikipedia


The term switchgear, used in association with the electric power system, or grid, refers to the combination of electrical disconnects, fuses and/or circuit breakers used to isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream. http://switchgear.askdefine.com/

And best yet for me. I will stop looking now: http://www.schneider-electric.com.a...al-installation-guide/EIG-H-LV-switchgear.pdf

Regardless of what evidence you find to the contrary, the above citings are enough for me to dismiss the rude snide remarks here and use the term switchgear to represent the all emcompassing category of switchgear!
 

shamsdebout

Senior Member
Location
Macon,GA
No, I read the definition provided and I still say that a switchboard falls under the term switchgear. Even the first line says "a general term"
Does not each of the popular gear manufacturers have products labeled Switchboard separate from Switchgear? The fact that they have separate products shows they are different units.

Here is what a popular gear rep said about the matter:
In a nutshell, low voltage switchgear is a particular type of assembly that must meet several ANSI standards and tests, and it is tested to UL1558 standards. Required features include Power Circuit breakers, draw-out construction, compartmentalization of the breakers, physical separation between the breakers and the bus, 30 cycle short circuit rating and 100% current rating of the circuit breakers. The testing is much more rigorous than for switchboards.

Switchboards are tested to the UL891 standard. Any freestanding grouping of bus-connected overcurrent protective devices that does not meet the standards of switchgear (above) would be considered a switchboard. Many are very much like panelboards except they are free-standing. Others are similar to switchgear, but don't have all of the features/testing required to meet the switchgear standard. You have to be a lot more specific about the features you want when specifying a switchboard, since there is such a wide offering.

In most cases, switchgear would be more expensive than a switchboard, but if you load up a switchboard with tons of optional features (that might be standard in switchgear), there is very little difference.

That said, switchgear is usually specified for more critical applications - healthcare, continuous industrial processes, data centers, labs, water/wastewater treatment, etc. Many universities also prefer switchgear, especially in buildings where research may be taking place. Some government facilities may also require switchgear, depending on the function and criticality of the building.
 
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Strathead

Senior Member
Does not each of the popular gear manufacturers have products labeled Switchboard separate from Switchgear? The fact that they have separate products shows they are different units.

Here is what a popular gear rep said about the matter:
In a nutshell, low voltage switchgear is a particular type of assembly that must meet several ANSI standards and tests, and it is tested to UL1558 standards. Required features include Power Circuit breakers, draw-out construction, compartmentalization of the breakers, physical separation between the breakers and the bus, 30 cycle short circuit rating and 100% current rating of the circuit breakers. The testing is much more rigorous than for switchboards.

Switchboards are tested to the UL891 standard. Any freestanding grouping of bus-connected overcurrent protective devices that does not meet the standards of switchgear (above) would be considered a switchboard. Many are very much like panelboards except they are free-standing. Others are similar to switchgear, but don't have all of the features/testing required to meet the switchgear standard. You have to be a lot more specific about the features you want when specifying a switchboard, since there is such a wide offering.

In most cases, switchgear would be more expensive than a switchboard, but if you load up a switchboard with tons of optional features (that might be standard in switchgear), there is very little difference.

That said, switchgear is usually specified for more critical applications - healthcare, continuous industrial processes, data centers, labs, water/wastewater treatment, etc. Many universities also prefer switchgear, especially in buildings where research may be taking place. Some government facilities may also require switchgear, depending on the function and criticality of the building.
And I eat crow and learn something new. Reading several definitions of switchgear I quoted and hearing the term switchgear encompass all distribution equipment regularly throughout my too many years in the trade. I must have never done a job where the manufacturer distinction of switchgear and switchboard was evidently relevant, so I didn't even realize what you say is true. When I read your post, I looked in the Square D catalogue and to my surprise there they were. Since words are important to me, I will not be misusing this one again.

Still think Zog and Weressl were being jerks. Have you really never heard of the "gear package" assumed to be short fo switchgear package? And if you have then you should have had the patience to be less dismissive.
 

zog

Senior Member
Location
Charlotte, NC
Still think Zog and Weressl were being jerks. Have you really never heard of the "gear package" assumed to be short fo switchgear package? And if you have then you should have had the patience to be less dismissive.
I hear terms used improperly everyday
 
T

T.M.Haja Sahib

Guest
Nope. You have made repeated false assertions what constitutes a switchgear. Did you check with the OP if he needed assistance with asking?
You are being carried away by your imagination. The OP is asking how to distinguish a switch gear from a switch board in the field. You are simply playing with IEEE definitions instead of agreeing on a workable consistent method for the OP to distinguish a switch gear from a switch board in the field.
 
T

T.M.Haja Sahib

Guest
I was only asking you to clarify WHAT is your statement "I disagree" refers to? That qualifies - in your book - as being a jerk? Woww
Perhaps he bases his conclusion on your responses in general? :)
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
You are being carried away by your imagination. The OP is asking how to distinguish a switch gear from a switch board in the field. You are simply playing with IEEE definitions instead of agreeing on a workable consistent method for the OP to distinguish a switch gear from a switch board in the field.
That was answered in post #9.
 

iwire

Moderator
Staff member
Location
Massachusetts
Have you really never heard of the "gear package" assumed to be short fo switchgear package?
Of course, and I hear grounded conductors called neutrals when they are not.

Point being there is trade slang / common usage and there is the standards. The fact they have different listings is enough for me to accept they are not the same.
 

shamsdebout

Senior Member
Location
Macon,GA
Of course, and I hear grounded conductors called neutrals when they are not.

Point being there is trade slang / common usage and there is the standards. The fact they have different listings is enough for me to accept they are not the same.

I thought in a solidly grounded system the neutral conductor is always connected to grounded so it would be both a grounded conductor and a neutral conductor.

Is that not so?
 
You are being carried away by your imagination. The OP is asking how to distinguish a switch gear from a switch board in the field. You are simply playing with IEEE definitions instead of agreeing on a workable consistent method for the OP to distinguish a switch gear from a switch board in the field.
False again. IEEE IS the definite authority on both, by establishing standards that ARE defining the features that distinguishes each. When these Standards are matured, established in industry practice and accepted by the user community they are elevated to ANSI Standard status.

But, I will play along.

What is the practical use 'in the field' to be able to distingush between the two?
 
No, they are different. Per IEEE:

Switchgear: A general term covering switching and interrupting devices and their combination with associated control, instrumentation, metering, protective and regulating devices with associated interconnections, accessories and supporting structures used primarily in connection with the generation, transmission, distribution and conversion of electric power.

Switchboard: A large single panel, frame or assembly of panels, on which are mounted, on the face or back or both, switches, overcurrent and other protective devices, buses and usually instruments.

Switchgear and switchboard structures are built and tested to different standards: Switchgear to ANSI standard C37.20.1, UL standard 1558, and NEMA standard SG-5, switchboards to NEMA PB-2, and UL-891. Switchgear incorporates only low-voltage power circuit breakers (LVPCB) which conform with ANSI C37.13, NEMA SG-3 and are listed per UL-1066, whereas switchboards may include any combination of protective devices including insulated case (ICCB), molded-case circuit breakers (MCCB) listed per UL-489, fusible switches listed per UL-508 and 977 and power circuit breakers listed to UL-1066.

Best way to know the difference, Switchgear is designed for flexibility and maximum protection, switchgear generally costs 2x what switchboards do. Switchboards are designed to be low cost, usually use cheap MCCB's or ICCB's, and have very few features.
Yes and no MCCB's are being built that are like 'crossovers' of breakers and suitable for both switchgear AND switchboard applications:

EATON

" Magnum DS / SB

Eaton’s Magnum Low Voltage Power Circuit Breakers are designed for ultimate custom configuration, application flexibility, and performance. Choose Magnum DS breakers for ANSI rated switchgear applications and Magnum SB insulated case breakers for switchboard applications.

They are the same base with slight difference between the DS and SB models. Not interchangeable though...The distinguishing name of Insulated Case.... instead of the Molded Case.... is the clue. The basic feature difference is that one is serviceable ICCB and the other one is rebuildable MCCB.
 
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iwire

Moderator
Staff member
Location
Massachusetts
I thought in a solidly grounded system the neutral conductor is always connected to grounded so it would be both a grounded conductor and a neutral conductor.

Is that not so?
Not always


Neutral Point. The common point on a wye-connection in
a polyphase system or midpoint on a single-phase, 3-wire
system, or midpoint of a single-phase portion of a 3-phase
delta system, or a midpoint of a 3-wire, direct-current system.

The grounded conductor from corner grounded delta would not be a neutral.
 
T

T.M.Haja Sahib

Guest
False again. IEEE IS the definite authority on both, by establishing standards that ARE defining the features that distinguishes each. When these Standards are matured, established in industry practice and accepted by the user community they are elevated to ANSI Standard status.
Obsessed with so called fault finding and missing out what may help the OP?
The point is there is no intention to challenge any thing but to find out the distinguishing features as present in UL1558 and UL 891 to enable the OP to distinguish between the switch gear and switchboard in the field.

But, I will play along.

What is the practical use 'in the field' to be able to distingush between the two?
Perhaps the OP does not want to be bamboozled by a contractor stating a switchboard as a switch gear as the former is less costly.
 
Not always





The grounded conductor from corner grounded delta would not be a neutral.
That maybe what bought along the grounded conductor definition. Neutral was originally used - as I was thought in school - to indicate that is neutral in relation to the ground, eg. has no potential difference between it and the earth/ground. In that sence a corner grounded delta would have no potential difference between it and the earth/ground.
 
T

T.M.Haja Sahib

Guest
Yes and no MCCB's are being built that are like 'crossovers' of breakers and suitable for both switchgear AND switchboard applications:

EATON

" Magnum DS / SB

Eaton’s Magnum Low Voltage Power Circuit Breakers are designed for ultimate custom configuration, application flexibility, and performance. Choose Magnum DS breakers for ANSI rated switchgear applications and Magnum SB insulated case breakers for switchboard applications.

They are the same base with slight difference between the DS and SB models. Not interchangeable though...The distinguishing name of Insulated Case.... instead of the Molded Case.... is the clue. The basic feature difference is that one is serviceable ICCB and the other one is rebuildable MCCB.
But where is the MCCB shown as used in switchgear?!
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
But where is the MCCB shown as used in switchgear?!
Technically, an ICCB is like an MCCB, but it is not exactly the same because it is an "insulated case" as opposed to a "molded case". But from a UL listing standpoint, they are considered the same. I think what he is saying (if I may be so bold) is that you can get a "breaker" that uses the same basic construction as a UL1066 Power Breaker, but is UL listed under UL489 and thus is called an ICCB so as to not confuse it with a PB. That means it can only be used in a Switch BOARD, not in Switch GEAR, but you can benefit from some of the same control and protection features in the breakers normally only found in Switch GEAR.

Jeez, this entire thread keeps dragging on with people wanting to argue that well defined, established and published industry standards are not valid, but loosey-goosey street slang or far flung foreign concepts that don't apply here are.

Enough already...
 
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