solid neutral
- Thread starter tcmalker
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physis
Senior Member
Re: solid neutral
I don't have much three phase experience and SN doesn't mean anything to me outside of maybe serial number. But I think there's enough information now to get an answer from some of the engineering guys.
Edit: Like Steve.
[ June 27, 2005, 05:20 PM: Message edited by: physis ]
I don't have much three phase experience and SN doesn't mean anything to me outside of maybe serial number. But I think there's enough information now to get an answer from some of the engineering guys.
Edit: Like Steve.
[ June 27, 2005, 05:20 PM: Message edited by: physis ]
- Location
- Massachusetts
Re: solid neutral
I have never seen the term 'solid neutral' applied to a panel.
I have only seen that term applied to transfer switches and in that case it means the neutral is not switched.
When applied to a panel all I can a imagine it means is a bonded neutral.
I have never seen the term 'solid neutral' applied to a panel.
I have only seen that term applied to transfer switches and in that case it means the neutral is not switched.
When applied to a panel all I can a imagine it means is a bonded neutral.
mdshunk
Senior Member
- Location
- Right here.
Re: solid neutral
"solid neutral" is a term often used for 120 volt HVAC contactors. The hot and neutral both hook on the top and bottom of the contactor, but only the hot side has contacts. The neutral side has a solid bar. The same definition applies to transfer switches. The neutral has terminals right in line with the phase terminals, but it is not switched as the phases are. The neutral in such an ATS has a long double ended mechanical lug of sorts.
[ June 27, 2005, 05:29 PM: Message edited by: mdshunk ]
"solid neutral" is a term often used for 120 volt HVAC contactors. The hot and neutral both hook on the top and bottom of the contactor, but only the hot side has contacts. The neutral side has a solid bar. The same definition applies to transfer switches. The neutral has terminals right in line with the phase terminals, but it is not switched as the phases are. The neutral in such an ATS has a long double ended mechanical lug of sorts.
[ June 27, 2005, 05:29 PM: Message edited by: mdshunk ]
- Location
- Massachusetts
Re: solid neutral
How is that for an ambiguous answer.
Many are, many are not.
How is that for an ambiguous answer.
physis
Senior Member
Re: solid neutral
I really don't know what makes the difference between a relay and a contactor. But I know that SPDT's and SPST's are called relays. And I don't remember anything with less than "DP" being called a contactor.
[ June 27, 2005, 05:46 PM: Message edited by: physis ]
I really don't know what makes the difference between a relay and a contactor. But I know that SPDT's and SPST's are called relays. And I don't remember anything with less than "DP" being called a contactor.
[ June 27, 2005, 05:46 PM: Message edited by: physis ]
- Location
- Massachusetts
Re: solid neutral
Originally posted by physis:
Edit: And I'm only going to give you a 5.5 on ambiguity.
I must try harder.
I am not sure what separates all the terms, relays, contactors, magnetic motor starters etc.
If you look in catalogs you can get all sorts of combinations of poles, switching, aux contacts etc.
I do no think there are any standard rules here.
- Location
- Massachusetts
Re: solid neutral
Sam I often install contactors for the interface of building control systems to the building systems.
The contactors are generally labeled one of two ways.
Definite Purpose Contactor"
or
General Purpose Contactor"
Both may have what appears to me to be identical characteristics.
2 - pole
double pole, single throw
30 amp
250 - volt
24 VAC coil
Sam I often install contactors for the interface of building control systems to the building systems.
The contactors are generally labeled one of two ways.
Definite Purpose Contactor"
or
General Purpose Contactor"
Both may have what appears to me to be identical characteristics.
2 - pole
double pole, single throw
30 amp
250 - volt
24 VAC coil
Re: solid neutral
my opinion is that relays range from 0-30 amps, while contactors are generally 20+ amps. I have seen both contactors and power relays in the 20-30 amp range.
-pole configuration is not a factor
-some contactors have a shunt pole (non-switched)
-Definite Purpose Contactors have a Locked Rotor Amp rating, I wonder if all General Purpose Contactors do?
Mike
[ June 27, 2005, 07:36 PM: Message edited by: mikesorel ]
my opinion is that relays range from 0-30 amps, while contactors are generally 20+ amps. I have seen both contactors and power relays in the 20-30 amp range.
-pole configuration is not a factor
-some contactors have a shunt pole (non-switched)
-Definite Purpose Contactors have a Locked Rotor Amp rating, I wonder if all General Purpose Contactors do?
Mike
[ June 27, 2005, 07:36 PM: Message edited by: mikesorel ]
pierre
Senior Member
- Location
- Westchester County, New York
Re: solid neutral
"the panel is in fact connected to an ATS."
Because of this answer, I am going to say that a a Solid Neutral and "Solidly Grounded" ('02, pg 83 - following 230.95 ) or "Grounded, Solidly" ('05, pg 28 Art 100) would mean the same.
If the transfer switch were to switch the neutral conductor it would not be "solidly grounded", if the transfer switch was not to switch the neutral conductor, then it would be "solidly grounded".
A 3 phase system with a 3-pole transfer switch would be solidly grounded (solid neutral)
A 3 phase system with a 4-pole transfer switch wound not solidly grounded.
This would help to determine if the system is "
Separately Derived"
"the panel is in fact connected to an ATS."
Because of this answer, I am going to say that a a Solid Neutral and "Solidly Grounded" ('02, pg 83 - following 230.95 ) or "Grounded, Solidly" ('05, pg 28 Art 100) would mean the same.
If the transfer switch were to switch the neutral conductor it would not be "solidly grounded", if the transfer switch was not to switch the neutral conductor, then it would be "solidly grounded".
A 3 phase system with a 3-pole transfer switch would be solidly grounded (solid neutral)
A 3 phase system with a 4-pole transfer switch wound not solidly grounded.
This would help to determine if the system is "
Separately Derived"
Re: solid neutral
I agree with Pierre.
In my experience the SN description is just our common, garden variety neutral in a panel. No switching is involved, it is solidly connected to the neutral thru any/all panels/disconnects/switchgear to the source of the neutral where it is solidly grounded (local xfmr or poco service).
The term also makes it plain that this would not be a resistance grounded neutral.
I agree with Pierre.
In my experience the SN description is just our common, garden variety neutral in a panel. No switching is involved, it is solidly connected to the neutral thru any/all panels/disconnects/switchgear to the source of the neutral where it is solidly grounded (local xfmr or poco service).
The term also makes it plain that this would not be a resistance grounded neutral.
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