An Emergency Panel - ECN Electrical Forums

This panelboard powers the lighting in the stairs and corridors, the exit fixtures, etc in a 9 story residential building.

In an outage, the 480V generator will power this panel through a little 30 KVA transformer.

And then..............?

[Linked Image]

Well Scott,
That transformer will work.... for a short time at least.
How could a thing like this happen?.
One other thing, I have certain mis-givings about that run of EMT over the top of that exhaust silencer as well, we all know how hot they get!. [Linked Image]

What exactly is wrong here...I thought the panel was not fed, but on closer look it seems there is a feeder coming in the bottom of what looks like a feed trhough panel.

Am I missing something stupidly obvious?

mike

Agreed, more info is needed here. Many of those 'silencers' (they're not called mufflers for a reason) are wrapped inside with fire and heat retardent. That means it may not get as hot as you'd think, but that should be in the submittal documents. It also appears that it was here for some time prior to the EMT, so who's problem is that?

I'd be more concerned with the "air over" portion of the cooling. That's something that will get overlooked over the years.

"the 480V generator will power this panel through a little 30 KVA transformer.

And then..............?"

While a 30KVA transformer looks a little undersized for the generator. (I am guessing by the 6cyl diesel that it is 60KW or more)
If it has a correctly sized OCD it should be fine electrically. No doubt the diesel will wet stackfrom being underloaded, but that is another story. Outside of the EMT over the exhaust, I don't see too much problem.
Well, I don't see any fire suppression system either, but that could just be outside of the photo.

30KVA for 9 stories is about 3KVA/floor. Depending on the size of each floor and types of fixtures on emergency power, that may be enough.

Since this is a lighting and appliance panel,408.36(D) requires overcurrent protection on the secondary side of the transformer. I don't see a main breaker or any other OCP device in the picture.

I would assume that the generator is powering more than just lighting, otherwise why would it be a 480v genset?

Sorry it took me so long to get back to this.

The 30 KVA is plenty to supply the loads that are fed here. My big concern is with the 1" EMT run right above the silencer.

This is not the original panel that was installed, it was installed, I believe, after this one about 10' away burnt out, . (And probably without a permit or inspection)

[Linked Image]

There's lots of heat coming off of that exhaust system. This has happened just during weekly tests of about 15 minutes.

[Linked Image]

Also, the panel is mounted right under the silencer's drain plug.

The 480V genset does supply other loads, but has enough capacity to handle them.

9 story building? 480v generator?

Can you say "elevator machinery"

Good call, Gus [Linked Image]

Exactly!!

What on earth is that melted there, Scott?. [Linked Image]

I would say it's telephone or possibly CATV.

The cable/splice case on the left is telephone,
and the cable might be lead sheathed pulp, as it does not appear to be melted.

The piping from the silencer appears to be mounted in space reserved for electrical conductors entering that panel per

Quote

110.26 Spaces About Electrical Equipment.
Sufficient access and working space shall be provided and maintained about all electric equipment to permit ready and safe operation and maintenance of such equipment. Enclosures housing electrical apparatus that are controlled by lock and key shall be considered accessible to qualified persons.
(F) Dedicated Equipment Space. All switchboards, panelboards, distribution boards, and motor control centers shall be located in dedicated spaces and protected from damage.
Exception: Control equipment that by its very nature or because of other rules of the Code must be adjacent to or within sight of its operating machinery shall be permitted in those locations.
(1) Indoor. Indoor installations shall comply with 110.26(F)(1)(a) through (d).
(a) Dedicated Electrical Space. The space equal to the width and depth of the equipment and extending from the floor to a height of 1.8 m (6 ft) above the equipment or to the structural ceiling, whichever is lower, shall be dedicated to the electrical installation. No piping, ducts, leak protection apparatus, or other equipment foreign to the electrical installation shall be located in this zone.

--
Tom Horne

[This message has been edited by tdhorne (edited 05-05-2006).]

However, as noted above, the original panel location was about 10' away, which means that the current panel was installed after the silencer.

Sorry I didn't see the earlier question.

The charred cable on the right is (or was) a phone line.

The lines on the left are a lineset for an airconditioner that services this E-room.
The suction line's insulation when in its normal condition is compressed slightly by the strut clamps.

There are 2-500KVA transformers in this room too, so it's pretty warm in there.