Commercial building with multiple 8 tenents. Will have one utility service drop. Have two masts (one to a 600 amp disconnect which connects to a wireway with connections to 4 meters/individual disconnects -- one to a wireway with connections to 4 meters/individual disconnects.) All equipment is grouped on exterior of building. Question: Is the 600 amp disconnect required to be fused.
Service Entrance Disconnect
- Thread starter eutaw42
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Re: Service Entrance Disconnect
Yes, the disconnect must be fused. You can have no more than 6 disconnects. It sounds like you have 8 total, so the electrician that built the service installed a MAIN DISCONNECT before the meters. Now the total disconnects is 5. This is common on strip malls and/or any service over 1000 amps. If the service is rated at 1000 amps or better it would require GFCI protection. If you break the service down with main disconnects before the meters you can avoid this costly addition.
Yes, the disconnect must be fused. You can have no more than 6 disconnects. It sounds like you have 8 total, so the electrician that built the service installed a MAIN DISCONNECT before the meters. Now the total disconnects is 5. This is common on strip malls and/or any service over 1000 amps. If the service is rated at 1000 amps or better it would require GFCI protection. If you break the service down with main disconnects before the meters you can avoid this costly addition.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Service Entrance Disconnect
The 600 amp disconnect is not a service disconnect and is not required to be fused, It is a meter disconnect that is ahead of the meters. 230.40 exception 1 allows each set of service entrance conductors to be run to each run to each occupancy or group of occupancies. then you are allowed up to 6 disconnects for each set of service entrance conductors. If you have the Analyst Of Code Changes for the 2005 put out by IAEI you will see where this has always been allowed but very mis-interpreted because of the reference to 230.2(D) in the wording which was changed for 2005.
This was discussed in this thread:
Topic: meter banks
The 600 amp disconnect is not a service disconnect and is not required to be fused, It is a meter disconnect that is ahead of the meters. 230.40 exception 1 allows each set of service entrance conductors to be run to each run to each occupancy or group of occupancies. then you are allowed up to 6 disconnects for each set of service entrance conductors. If you have the Analyst Of Code Changes for the 2005 put out by IAEI you will see where this has always been allowed but very mis-interpreted because of the reference to 230.2(D) in the wording which was changed for 2005.
This was discussed in this thread:
Topic: meter banks
pierre
Senior Member
- Location
- Westchester County, New York
Re: Service Entrance Disconnect
The disconnect in front of the meter(bank) is still a service disconnect.
Look at the definition of service and service conductors in Art 100.
[ March 06, 2005, 08:10 PM: Message edited by: pierre ]
The disconnect in front of the meter(bank) is still a service disconnect.
Look at the definition of service and service conductors in Art 100.
[ March 06, 2005, 08:10 PM: Message edited by: pierre ]
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Service Entrance Disconnect
Pierre Look at 230.82(2):
If you look at figure 230.1 at the point of just before the service entrance conductors you will see at the right it says terminal box, meter, or other enclosure, Other enclosure is what I would think it would fall under and it is ahead of the meter, service disconnect and service entrance conductors?
Pierre Look at 230.82(2):
If they are allowed to be connected ahead of the service disconnect then how can it be one in the same? Yes if there was no "fused disconects" after this point then I would say it was the service disconnect but I have seen many installs on apartments where it is ahead of the meters and does not have any OCPDs which would be required if it was a service disconnect.
If you look at figure 230.1 at the point of just before the service entrance conductors you will see at the right it says terminal box, meter, or other enclosure, Other enclosure is what I would think it would fall under and it is ahead of the meter, service disconnect and service entrance conductors?
charlie
Senior Member
- Location
- Indianapolis
Re: Service Entrance Disconnect
If it is a meter disconnect, it will be under the exclusive control of the serving electric utility.
If it is a meter disconnect, it will be under the exclusive control of the serving electric utility.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Service Entrance Disconnect
Charlie I have seen several services on apartment buildings where there was a large unprotected disconnect ahead of all the gained meters but each meter always had a breaker for each unit. and I have seen where there was a fused disconnect ahead of meters but the meters didn't have a breaker for each unit but had main breaker panels in each unit or had less than 6 breakers in each panel. Which would be called a meter disconnect?
Charlie I have seen several services on apartment buildings where there was a large unprotected disconnect ahead of all the gained meters but each meter always had a breaker for each unit. and I have seen where there was a fused disconnect ahead of meters but the meters didn't have a breaker for each unit but had main breaker panels in each unit or had less than 6 breakers in each panel. Which would be called a meter disconnect?
Re: Service Entrance Disconnect
Well folks -- I want to meet the six disconnect rule -- again have 4 beaker disconnects on one mast and need to install a main disconnect on the other mast feeding the other 4 breaker disconnects(each of which is sized for the tenant load). Flat out -- required to fuse the large main or not? The only difference between the two masts is the added main disconnect to stay within the 6 disconnect rule. 4 tenant disconnects are within 5' of the main. --- lot of good discussion -- learned some -- but there seems to be some disagreement on fuse or not -- or am I quite understanding everyone?
Well folks -- I want to meet the six disconnect rule -- again have 4 beaker disconnects on one mast and need to install a main disconnect on the other mast feeding the other 4 breaker disconnects(each of which is sized for the tenant load). Flat out -- required to fuse the large main or not? The only difference between the two masts is the added main disconnect to stay within the 6 disconnect rule. 4 tenant disconnects are within 5' of the main. --- lot of good discussion -- learned some -- but there seems to be some disagreement on fuse or not -- or am I quite understanding everyone?
physis
Senior Member
Re: Service Entrance Disconnect
Unless I'm missing something, I think you can find your answer here:
Article 100
Service Equipment. The necessary equipment, usually consisting of a circuit breaker(s) or switch(es) and fuse(s) and their accessories, connected to the load end of service conductors to a building or other structure or an otherwise designated area, and intended to constitute the main control and cutoff of the supply.
My reading of this puts no requirement for overcurrent protection of any kind on the disconnecting means.
Usually consisting of is not a requirement.
Article 230 Part VI covers Service Equipment - Disconnecting Means. And I don't see a requirement there for the disconnect to provide any overcurrent protection.
Unless I'm missing something, I think you can find your answer here:
Article 100
Service Equipment. The necessary equipment, usually consisting of a circuit breaker(s) or switch(es) and fuse(s) and their accessories, connected to the load end of service conductors to a building or other structure or an otherwise designated area, and intended to constitute the main control and cutoff of the supply.
My reading of this puts no requirement for overcurrent protection of any kind on the disconnecting means.
Usually consisting of is not a requirement.
Article 230 Part VI covers Service Equipment - Disconnecting Means. And I don't see a requirement there for the disconnect to provide any overcurrent protection.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Service Entrance Disconnect
sounds like you have the same question that was asked in this thread:
Meter Banks
From what I have been told and from what was changed in the 2005 NEC exception 1 for 230.40 would allow more than 6 disconnects as it says you are allowed 6 per each set of service entrance cables and it sounds like you only have 4 per each set? If you have the book "Analysis Of Changes (2005)" It will tell you about why they removed the referance to 230.2(D) as it wasn't supose to be in there.
Does this image look like what you have?
sounds like you have the same question that was asked in this thread:
Meter Banks
From what I have been told and from what was changed in the 2005 NEC exception 1 for 230.40 would allow more than 6 disconnects as it says you are allowed 6 per each set of service entrance cables and it sounds like you only have 4 per each set? If you have the book "Analysis Of Changes (2005)" It will tell you about why they removed the referance to 230.2(D) as it wasn't supose to be in there.
Does this image look like what you have?
charlie
Senior Member
- Location
- Indianapolis
Re: Service Entrance Disconnect
The second one is an example of a service disconnecting means with overcurrent protection and the rest is now feeders to lighting and appliance panelboards.
The first one would have likely been a meter disconnect but the Code would have been violated since more than six service disconnecting means would have been grouped together.
The second one is an example of a service disconnecting means with overcurrent protection and the rest is now feeders to lighting and appliance panelboards.
Re: Service Entrance Disconnect
In my area - inspection will not accept more than six disconnects (grouped together) for one utility service drop. The number of masts is not a factor. --- First time that I had heard of a meter disconnect except where the utility co. required one on 480 volt direct metering (they now require CT metering for this and have meter base inside switch for some 400 amp direct metering - 240 volt). -- I will just require fusing and no one can say it is not a service disconnect. -- will then have 5 disconnects grouped together. Thanks for all your info.
In my area - inspection will not accept more than six disconnects (grouped together) for one utility service drop. The number of masts is not a factor. --- First time that I had heard of a meter disconnect except where the utility co. required one on 480 volt direct metering (they now require CT metering for this and have meter base inside switch for some 400 amp direct metering - 240 volt). -- I will just require fusing and no one can say it is not a service disconnect. -- will then have 5 disconnects grouped together. Thanks for all your info.
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