Service Disconnect feeds two MLO panels

[senoirbubbles]

I recently ran into an older commercial building with multiple units. There is a 800 amp disconnect that feeds a trough with approx 6-200 amp disconnects. My question is regarding one of the 200 amp disconnects. On the load side of the disconnect 3/0 wire feeds into a junction box in the ceiling about 10 feet from the disconnect. There in the junction box they split off via 2/0( it could be 3/0 I need to look again) wire to two separate MLO panels.The panels are about 20 feet away from the junction box. No EGC was run from the Main disconnect, I assume the conduit is being used as the ground. My questions are:

1) Is this up to code? I have never seen two panels run off of one disconnect and do not think the tap rule can apply.Would it be okay if each panel had an OCP?
2) Assuming the panels are wired correctly, Would I be required to add a ground wire or would the conduit suffice as the EGC for the panels.

 

[iwire]

.On the load side of the disconnect 3/0 wire feeds into a junction box in the ceiling about 10 feet from the disconnect. There in the junction box they split off via 2/0( it could be 3/0 I need to look again) wire to two separate MLO panels.The panels are about 20 feet away from the junction box. No EGC was run from the Main disconnect, I assume the conduit is being used as the ground. My questions are:

1) Is this up to code? I have never seen two panels run off of one disconnect and do not think the tap rule can apply.Would it be okay if each panel had an OCP?

As long as all the conductors and both panels have ratings higher than the fuses in the disconnect you do not have any taps, you have a feeder that spits into two directions.

This is perfectly fine and you could add more panels to this one disconnect if the load calculations remain under the fuse in the disconnect. .

2) Assuming the panels are wired correctly, Would I be required to add a ground wire or would the conduit suffice as the EGC for the panels.

Conduit is a equipment grounding conductor, see 250.118.

 

[electrofelon]

I recently ran into an older commercial building with multiple units. There is a 800 amp disconnect that feeds a trough with approx 6-200 amp disconnects. My question is regarding one of the 200 amp disconnects. On the load side of the disconnect 3/0 wire feeds into a junction box in the ceiling about 10 feet from the disconnect. There in the junction box they split off via 2/0( it could be 3/0 I need to look again) wire to two separate MLO panels.The panels are about 20 feet away from the junction box. No EGC was run from the Main disconnect, I assume the conduit is being used as the ground. My questions are:

1) Is this up to code? I have never seen two panels run off of one disconnect and do not think the tap rule can apply.Would it be okay if each panel had an OCP?
2) Assuming the panels are wired correctly, Would I be required to add a ground wire or would the conduit suffice as the EGC for the panels.

Sounds like it is in violation of 408.36

 

[iwire]

Sounds like it is in violation of 408.36

I don't see how if they are rated above the fuse size.

 

[augie47]

I'm on board with Iwire. As long as the conductors and MLO panels are rated at least 200 amp, the 200 amp disconnect ahead of the panels meets the NEC.

 

[NYSolar]

I thoght you couldn't have OCP in parallel?

 

[iwire]

I thoght you couldn't have OCP in parallel?

As described there are no OCPs in parallel.

 

[cpinetree]

The only problem would be if it is 2/0 Cu rated 175amps at the termination.
If it is 3/0 feeding each panel then it seems compliant.

 

[electrofelon]

I don't see how if they are rated above the fuse size.

I agree. Some how missed the disconnects in the description

 

[senoirbubbles]

As long as all the conductors and both panels have ratings higher than the fuses in the disconnect you do not have any taps, you have a feeder that spits into two directions.

This is perfectly fine and you could add more panels to this one disconnect if the load calculations remain under the fuse in the disconnect. .





Conduit is a equipment grounding conductor, see 250.118.

Sounds good thank you for the advice I really appreciate it! One more question. I work in a lot of Condominiums here in Florida. Many of them have individual panels in each unit which have their feeders run in metal pipe. All the outlets are also usually run in pipe. In 95% of the cases they run a wire for the EGC in addition to having the metal pipe as a ground. It appears the pipe is a perfectly good ground so why the copper wire in addition to the pipe.I have always run a green ground wire when running circuits through emt. Have I and every electrician I know been doing this in the name of overkill all this time???