7th disconnect ever allowed?

[sparkycoog]

I have run across this question a couple of times now and I'm pretty sure I have missed it each time, but can there ever be a 7th disconnect? 230.2A 1-6 does allow for a second service (like for fire pumps parallel power, etc) but sections 230.71 and 230.72 are very strict in the wording that a max of 6 shoukd exist and out of the 2 to 6 only one of the can be located remotely. So again, is there any room for interpretation to allow for one more? The reason I ask is because in Mike Holt's exam prep book, on page 133 figure 5-24 he has a 7th disconnect which is a PV disconnect and I'm sure it's not an accident.What's the good word?

 

[GoldDigger]

I have run across this question a couple of times now and I'm pretty sure I have missed it each time, but can there ever be a 7th disconnect? 230.2A 1-6 does allow for a second service (like for fire pumps parallel power, etc) but sections 230.71 and 230.72 are very strict in the wording that a max of 6 shoukd exist and out of the 2 to 6 only one of the can be located remotely. So again, is there any room for interpretation to allow for one more? The reason I ask is because in Mike Holt's exam prep book, on page 133 figure 5-24 he has a 7th disconnect which is a PV disconnect and I'm sure it's not an accident.What's the good word?

My guess is that it is because the PV is considered a source and not a load, so it would not be a service disconnect?
The rules for line-side taps for PV are somewhat different, and without looking at Mike's guide I cannot tell whether that is the situation or not.

 

[Smart $]

The requirement is no more than six grouped in any one location, not six total, period... though six total would be the case if there is only one set of service entrance conductors.

Note the requirement is for each service or each set of service entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5.

 

[kwired]

The requirement is no more than six grouped in any one location, not six total, period... though six total would be the case if there is only one set of service entrance conductors.

Note the requirement is for each service or each set of service entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5.

:thumbsup:

I would like to emphasize your note at the end: each service or each ....set .....permitted by...

Since this is an alternate source, it really has nothing to do with the service... until we want to tie it into the same system supplied by the service. Same thing goes for any other alternate source that we want to tie into the same system, in case some forgot there is more alternate sources out there besides PV that could be tied in similar fashion to your distribution system.

 

[Smart $]

:thumbsup:

I would like to emphasize your note at the end: each service or each ....set .....permitted by...

Since this is an alternate source, it really has nothing to do with the service... until we want to tie it into the same system supplied by the service. Same thing goes for any other alternate source that we want to tie into the same system, in case some forgot there is more alternate sources out there besides PV that could be tied in similar fashion to your distribution system.

Agreed on the alternate source issue. I just wanted to point out more than six [actual] service disconnecting means total is possible, because disconnecting means appears to be more the subject while the PV disconnect in MH exam prep just happened to be the example creating the confusion.

 

[sparkycoog]

The requirement is no more than six grouped in any one location, not six total, period... though six total would be the case if there is only one set of service entrance conductors.

Note the requirement is for each service or each set of service entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5.

I understand that it's 6 grouped in one location and not 6 total, but the picture I was referencing in the Mike Holt book has 7 disconnects grouped together with the PV disconnect being the 7th.

Is it then correct to assume that if we have an approved 2nd (or multiple) services (or sources of power), per 230.2 which supply the following: Fire pumps, Emergency systems, Legally required standby systems, Optional standby systems, Parallel power production system, or Systems designed for connection to multiple sources ofsupply for the purpose of enhanced reliability, then the exceptions in 230.40 allow us to keep the above service disconnects grouped with the 6 main service disconnects?

So really, Can we have the following grouped together:

Main1 Main2 Main3 Main4 Main5 Main6 PV Disconnect, Firepump disconnect, Generator disconnect?



If you have another source of power coming in (whether it's a generator, PV system, etc), does that somehow become an exeption?

 

[Smart $]

I understand that it's 6 grouped in one location and not 6 total, but the picture I was referencing in the Mike Holt book has 7 disconnects grouped together with the PV disconnect being the 7th.

Is it then correct to assume that if we have an approved 2nd (or multiple) services (or sources of power), per 230.2 which supply the following: Fire pumps, Emergency systems, Legally required standby systems, Optional standby systems, Parallel power production system, or Systems designed for connection to multiple sources ofsupply for the purpose of enhanced reliability, then the exceptions in 230.40 allow us to keep the above service disconnects grouped with the 6 main service disconnects?

So really, Can we have the following grouped together:

Main1 Main2 Main3 Main4 Main5 Main6 PV Disconnect, Firepump disconnect, Generator disconnect?



If you have another source of power coming in (whether it's a generator, PV system, etc), does that somehow become an exeption?

Not an exception if it is a grid-tied parallel power production source, which is not the same as a fire pump that is service supplied or an emergency or standby system (i.e. switched manually or automatically on loss of normal service).

IMO the "7th disconnect" we are discussing should be remotely located... but current Code does not support that as a requirement.

 

[kwired]

I understand that it's 6 grouped in one location and not 6 total, but the picture I was referencing in the Mike Holt book has 7 disconnects grouped together with the PV disconnect being the 7th.

Is it then correct to assume that if we have an approved 2nd (or multiple) services (or sources of power), per 230.2 which supply the following: Fire pumps, Emergency systems, Legally required standby systems, Optional standby systems, Parallel power production system, or Systems designed for connection to multiple sources ofsupply for the purpose of enhanced reliability, then the exceptions in 230.40 allow us to keep the above service disconnects grouped with the 6 main service disconnects?

So really, Can we have the following grouped together:

Main1 Main2 Main3 Main4 Main5 Main6 PV Disconnect, Firepump disconnect, Generator disconnect?



If you have another source of power coming in (whether it's a generator, PV system, etc), does that somehow become an exeption?

If you have two voltage systems supplying one building, you can have six disconnects for each, plus any mentioned exceptions, they can all be in one location or AFAIK in separate locations. The generator would depend how it is tied in. If it is connected as a parallel power production source then it is not considered a separate source just like PV connected in this way. If PV is not connected as parallel power production it also would be a separate source and could have up to six disconnecting means. I think so anyway, someone will jump all over this if it is wrong

The fire pump disconnect is allowed to be in addition to the six disconnect rule, but it is not supposed to be grouped with the other disconnecting means, I believe this is to help prevent turning off fire pump in the case you are disconnecting all other facility power.

 

[sparkycoog]

Not an exception if it is a grid-tied parallel power production source, which is not the same as a fire pump that is service supplied or an emergency or standby system (i.e. switched manually or automatically on loss of normal service).

IMO the "7th disconnect" we are discussing should be remotely located... but current Code does not support that as a requirement.

I think I see what you mean, but how is a firepump allowed since it IS a grid tied source? Is it because it doesn't actually tie into the rest of the building? I know if it's part of the same service then it still counts as one of the 6 though it can be connected remotely, but if it has its own service, it can be the 7th disconnect?

 

[kwired]

I think I see what you mean, but how is a firepump allowed since it IS a grid tied source? Is it because it doesn't actually tie into the rest of the building? I know if it's part of the same service then it still counts as one of the 6 though it can be connected remotely, but if it has its own service, it can be the 7th disconnect?

A fire pump can tie to the "usual" service conductors or it can have totally separate service. Either way it is not counted as one of the allowed six disconnecting means per service. It also is not permitted to be grouped with the normal power service disconnecting means, they don't want someone disconnecting power to the facility to turn off the fire pump. Kind of worst case scenario: you don't want fire department showing up and one of first standard procedures for them is to shut off all electrical power, gas, or any other energy source to the facility, but the one thing in that situation you don't want energy removed from is the fire pump, putting that disconnect remote from the others helps a lot to prevent this from happening.

 

[shortcircuit2]

I have run across this question a couple of times now and I'm pretty sure I have missed it each time, but can there ever be a 7th disconnect? 230.2A 1-6 does allow for a second service (like for fire pumps parallel power, etc) but sections 230.71 and 230.72 are very strict in the wording that a max of 6 shoukd exist and out of the 2 to 6 only one of the can be located remotely. So again, is there any room for interpretation to allow for one more? The reason I ask is because in Mike Holt's exam prep book, on page 133 figure 5-24 he has a 7th disconnect which is a PV disconnect and I'm sure it's not an accident.What's the good word?

IMO...a line side connection to existing service entrance (for...Solar photovoltaic systems, fuel cell systems, or interconnected electric power production sources.) just creates an additional service disconnect and is subject to the 6-switch rule with respect to the existing service. The addition of the new service switch must be grouped with the other service disconnects.

I base my reasoning on the basis that there is only one SERVICE POINT, thereby it is one service and must adhere to the laundry list applying to services. If an additional service point were added to the building, then we could consider the new equipment a 2nd additional service and could have up to 6 switches.

There has been much debate on this subject. In the interest of safety for first responders to a building that is on fire, it is best to have all disconnects of a service grouped(except the fire pump disco), thereby allowing speedy shutdown without confusion.

 

[kwired]

IMO...a line side connection to existing service entrance (for...Solar photovoltaic systems, fuel cell systems, or interconnected electric power production sources.) just creates an additional service disconnect and is subject to the 6-switch rule with respect to the existing service. The addition of the new service switch must be grouped with the other service disconnects.

I base my reasoning on the basis that there is only one SERVICE POINT, thereby it is one service and must adhere to the laundry list applying to services. If an additional service point were added to the building, then we could consider the new equipment a 2nd additional service and could have up to 6 switches.

There has been much debate on this subject. In the interest of safety for first responders to a building that is on fire, it is best to have all disconnects of a service grouped(except the fire pump disco), thereby allowing speedy shutdown without confusion.

Agree, but will add there are limited instances where the second "service point" is permitted also. The fire pump is one exception, different voltage, frequency, number of phases, or other characteristics is another exception. Interconnected power production sources are of same voltage, frequency, number of phases, etc. as the system they interconnect to.

 

[Smart $]

IMO...a line side connection to existing service entrance (for...Solar photovoltaic systems, fuel cell systems, or interconnected electric power production sources.) just creates an additional service disconnect and is subject to the 6-switch rule with respect to the existing service. The addition of the new service switch must be grouped with the other service disconnects.

I base my reasoning on the basis that there is only one SERVICE POINT, thereby it is one service and must adhere to the laundry list applying to services. If an additional service point were added to the building, then we could consider the new equipment a 2nd additional service and could have up to 6 switches.

There has been much debate on this subject. In the interest of safety for first responders to a building that is on fire, it is best to have all disconnects of a service grouped(except the fire pump disco), thereby allowing speedy shutdown without confusion.

That is correct for only one set of service entrance conductors. Say for example the PV system (i.e. line-side connection) is tied into a service MLO MDP.

Now if in connecting the PV system a second or additional service entrance conductor set is established, that falls under 230.82(6), which is covered in 230.40, Exception No. 5. and thus 230.71(A)... and in such case, the PV system disconnect(s) MUST be located remote to the normal service disconnecting means enclosure or group of separate enclosures.

 

[Smart $]

... and in such case, the PV system disconnect(s) MUST be located remote to the normal service disconnecting means enclosure or group of separate enclosures.

That is, if the total disconnect count exceeds six.