24/365 facility add main and panel surge protectors.

[fmtjfw]

I'm 95% certain we just won a job to add a main surge protector on the load side of the ATS and smaller surge protectors at many of the panelboards. The catch is, we can not shut the place down, period. Fortunately, as far as anyone knows, all the critical loads are on rackmounted 20A or larger UPSes.

We also have to shutdown the feed to one of the buildings because it originally had a separate service and is now being fed from a feeder from the main building. We read 14A on the grounding wires in the feeder. The feeder comes out service heads near the original service entrance head and is spliced in the open air with the original conductors. The grounding wires are connected to the RMCs for the original service with pipe bonding clamps. We suspect that the neutral/grounding tie in the original feeder was never broken.

It's gone to be interesting, we're budgeting $5--10K just for temporary power and temporary wiring.

 

[fmtjfw]

This is the second time we've bid it and told them that if they don't take this bid, if they ask in the future, we will change them $1000 to prepare a third bid.

 

[fmtjfw]

Small surge suppressors

Small surge suppressors

This installation of the small surge suppressors is pretty simple, tap into the feeder to the panelboard, connect to a 3-phase, 30A fused disconnect and then into the brick. The idea of using the "knife-switch-like" disconnect and tubular fuses is to allow the high frequency components of the surge a straight, low impedance path.

 

[fmtjfw]

Temporary wiring

Temporary wiring

The design of the temporary wiring is the most interesting part. It will be in place for weeks (planning to do installation of surge suppressors during "off-peak" operations, so that if a failure occurs, revenue damage is limited. We will also be staging the work so that a minimum amount of equipment will not be dual-sourced (commercial & generator via ATS) at any given time.

When it's all done we'll be making a major donation of "used" NM and USE and ?? cable and receptacles to a local high school technical center electrical program.

 

[iwire]

What OSHA exception allows this work to be done hot?

 

[fmtjfw]

Hot work for measurement only

Hot work for measurement only

What OSHA exception allows this work to be done hot?

Don't know, never looked. [We are not subject to OSHA by the way -- no employees]

We will be opening panels and troughs for measurements (electrical) and inspection with HR3 equivalent clothing, meterman's gloves (1kV), hard hats with face shields, ear protection, safety glasses, CAT IV meters, and, if needed, 1000V IEC rated insulated tools.

The service is 120/208V 800A.

We have no intention of doing any hot work when we are installing the new equipment. The risk to personnel and the possibility of an accident shutting down any of their process is too great.

I have standing orders with my co-worker -- if they are life-flighting me to the regional burn center after an arc-flash incident, they are to shoot me before I'm loaded into the chopper.

 

[fmtjfw]

I have standing orders with my co-worker -- if they are life-flighting me to the regional burn center after an arc-flash incident, they are to shoot me before I'm loaded into the chopper.

There are these two hunters out in the woods, but in an area that has cellphone service. One hunter has a heart attack. The other hunter dials 911 and explains his buddy has had a heart attack and appears to be dead. The 911 operator asks "make sure he is dead". The hunter replies "just a second". BAM "yep".:happyno:

 

[ron]

What is the plan to temp out the loads without an outage? Will you be connecting the second source to the load conductors and running the two sources in parallel, then disconnecting the old source?

 

[fmtjfw]

unplg / plug

unplg / plug

What is the plan to temp out the loads without an outage? Will you be connecting the second source to the load conductors and running the two sources in parallel, then disconnecting the old source?

Every critical load, except air conditioning, is supplied from a UPS which is plug connected. We'll be using a zillion temp branch circuits from a separate source. The UPSes can handle the 1 minute max unplug, plug -- if they can't that is good info for the owner who will have one of his engineers fix that.

They have recently had a 20 minute production outage from a 2-second power outage. They suspect that there is either a bad UPS somewhere or a critical device not UPSed. This might help narrow that down.

Air conditioning can be off for 5 or more minutes, swap sources for them as well (but not now plug connected).

[Two years ago we did a server room with a huge UPS that supplied not only the computer equipment but also the air conditioning equipment, all backed up by a dedicated generator for the room alone.]

 

[jtinge]

Don't know, never looked. [We are not subject to OSHA by the way -- no employees].

Can you explain this?



Sent from my iPhone using Tapatalk

 

[fmtjfw]

Can you explain this?



Sent from my iPhone using Tapatalk

You must have employees to have OSHA regulations apply.

http://www.nolo.com/legal-encyclopedia/osha-complying-workplace-health-safety-laws-29567.html

see paragraph 8

.NOTE: we have no intention of working unsafely. We will be following 70E and using common sense.

 

[jtinge]

So you don't use employees?


Sent from my iPhone using Tapatalk

 

[fmtjfw]

So you don't use employees?


Sent from my iPhone using Tapatalk

Correct there are just two of us, neither is an employee.

 

[zbang]

The UPSes can handle the 1 minute max unplug, plug -- if they can't that is good info for the owner who will have one of his engineers fix that.

That's hardly a UPS in my book, that is unless you're absolutely guaranteed that a generator will start and supply load in that time.

 

[fmtjfw]

Sorry, I was unclear.

Sorry, I was unclear.

That's hardly a UPS in my book, that is unless you're absolutely guaranteed that a generator will start and supply load in that time.

Wasn't clear the UPSes will probably carry the load 15 minutes plus.

I don't expect an interruption of more than a minute to unplug a UPS and plug it into another source.

 

[zbang]

Right. That makes much more sense.