ECN Forum Forums General Topics of the Trade General Discussion Area What Should A Commercial Electrician Know?

ShockMe77,

Glad my list was relevant!
Please excuse the ambiguous terms used, I will explain a few in some detail, later in this message.

Nevertheless, most of the things I listed, will be commonly dealt with in Commercial / Industrial work, which differ from what is commonly dealt with in Residential work.

The most noticeable and "Stand-Out'ish" difference between "Common" Commercial work and most Residential work is Framing Materials!

Commercial is mostly Steel Studs (all gauges - some for Drywall Partitions, others for Structural) for Interior Walls, and "building envelopes" (Structural Walls) may be Concrete Tilt-Up Panels, Masonry, Steel Panels, Steel Beam framed, and the occasional Wood-Framed Building.

When 2 floors are involved within a Tilt-Up, the Interior Framing involved may be Wood, or Structural Steel.
Nearly all Structural Roof items for Tilt-Ups are Wood (Laminated Beams, Plywood Roofing, Solid Wood Purlins).

Floors on levels above 1st floors may be of "Elastocrete" (a light weight type of Concrete) - poured on Plywood Decking, or 4" and 6" thick common concrete, poured on top of either Plywood Decking, or Corrugated Steel Decking (AKA "Robinson Decking").

Other drastic changes will be the size and capacity of Service equipment (Physical and Electrical sizes), Panelboards in remote locations, Transformers here and there, actual (hopefully!) workable Plans, and dealing with Conduits of many sizes (1/2" up to 4").

I am sure you are very aware of these differences, so I will close that chapter and move on to "Whaddaheck Does That Mean" items of my posted list


*** List #"E": Rated Corridors and Ceilings ***

*** Reply: Like plenum rated ceilings? ***

Actually I was referring to Fire Rated Corridors, Walls and Ceilings + Demising Walls; but Plenum Ratings for Cable jackets used in Plenum return air ceilings is also relevant!

*** List #"G": Large Service Equipment ***

*** Reply: I can identify a closed delta from an open delta, and know the difference between a delta and wye configuration. Delta transformers are wired in series, wye's in parallel ***

This item was to refer to the physical sizes and capacities of Commercial / Industrial based Service Equipment, in addition to the various types of System Configurations one may encounter.
Keep in mind that 4 Wire Deltas (the ones with the "High Leg), may be derived from "Open Delta Vee" and Closed Delta configurations; and 3 Phase 3 Wire Deltas may also be Open Vee types or Closed types - and come in both Grounded and Ungrounded flavors!.

*** List #H: Troffer type Fluorescent Lighting Fixtures ***

*** Reply: Not sure what a "troffer type" fluorescent is but I'll guess it's either a high-bay type or a reflective lens type ***

This is a "Fancy" term for "2x2" and "2x4" Fluorescent Fixtures.

*** List #I: Complete Plansets!!! (how to read and install per "A", "M", "E", "P" and "S" Sheets) ***

*** Reply: What is A, M, E, P, & S abbreviated for? I am somewhat ok with reading prints, but not perfect ***

Sorry for the initials!
"A" = Architectural Sheets,
"M" = Mechanical Sheets (HVAC and similar),
"E" = Electrical Sheets (used and referred to 90% of the time),
"P" = Plumbing Sheets,
"S" = Structural Sheets.

There are others, which are the "Vendor-Specific" Plans, and "Specific Systems / Equipment" Plans.

*** List #J: RFIs ***

Acronym for "Request For Information" - a document / set of documents sent to Design Staff (Architects, Engineers, etc.) and/or to Contractors, to find out what the heck is needed - due to an unclear or missing piece of information on the Plans.
RFIs are generally written up, with a brief description of the issue and references to Plan Page(s).
Also known as a "WTF" (What The Foooo..)
Other similar documents are RFC (Request For Clarification), Change Order requests, FWO (Field Work Orders) and the lovely "Walk Through Punch Lists"!

*** List #X: Fault Levels exceeding 10KA, ***
This is where you will begin to see OCPDs with AIC / AIR listings at 18KA, 22KA, 30KA, 42KA, 65KA, 100KA and 200KA - and when + where to use them.
Also, keep a clean change of Pants + Underwear handy - these will be needed when you experience your first accidental Ground Fault on a High capacity System!

One other item - which goes in conjunction with "Service Equipment" is GFPE Protected Main Disconnects.
Ground faulting on the Load side of 480Y/277V 3 Phase 4 Wire Solidly Grounded Wye Systems of 1,000 Amps and larger, will result in tripping the _MAIN SERVICE DISCONNECT_
When this happens, it brings down the entire Building on that service.
Indications of tripping a GFPE main are:
* Only Emergency Lighting is on,
* Kwh Meter at the Main Service is not spinning / recording any consumption,
* Pissed-Off Tenants wandering around, looking for someone to point fingers at,
* A distant sound of the Back-Up Generator starting.

*** List #Z: PLC and similar type control equipment ***

Not too much PLC stuff (would be nice, but only if you want the knowledge), but more in the lines of "EMC" / "BAS" Equipment.

"EMC" = Energy Management Controllers (AKA Energy Management Systems - or "EMS") consist of Programmable type Controllers driving Relays and Contactors, which control Lighting and HVAC Equipment.

"BAS" = Building Automation Systems, which are similar to an "EMC", but may be more Integrated / sophisticated, or involving more than just Lighting and HVAC Systems for a given Client.

Both types may be comprised of "Simple" Programmable Time Switches (Electronic types, Astronomical, 7 day, multi events, programmable),
or be "LON-Based" Programmable (Local Operational Network Based - like Ethernet LANs, only the data in packets is simply Control information, sent to/from assigned addresses).

These Systems are very interesting, and may be extremely detailed.

A basic knowledge of these systems - and any Addressable Systems or Specific Systems (BAS, COMM/DATA, Fire Alarms, Security / CCTV) is something to think about gaining over time - as it will be very helpful to know what is involved in these types of systems.

Good luck!!!
Feel free to ask more questions!

.....Also, keep a clean change of Pants + Underwear handy - these will be needed when you experience your first accidental Ground Fault on a High capacity System!.....

hehehe,
and remember where the exit door is too ...

OK, tripping the GF in a building does result in a lot of p/o'd people. It also can result in a lot bigger problems.

Do it once....you learn!
John

If you are working in retail or offices you will have to consider safety of not only the employees, but their clients.

Lockout and tag-out procedures.

Local fire codes; watch for penetration of fire walls.

There will be more scheduling for commercial work than for residential. A lot of jobs will require afternoon or nightshifts to minimize disruption.

{Qouted by Scott35}

"One other item - which goes in conjunction with "Service Equipment" is GFPE Protected Main Disconnects.
Ground faulting on the Load side of 480Y/277V 3 Phase 4 Wire Solidly Grounded Wye Systems of 1,000 Amps and larger, will result in tripping the _MAIN SERVICE DISCONNECT_
When this happens, it brings down the entire Building on that service.
Indications of tripping a GFPE main are:
* Only Emergency Lighting is on,
* Kwh Meter at the Main Service is not spinning / recording any consumption,
* Pissed-Off Tenants wandering around, looking for someone to point fingers at,
* A distant sound of the Back-Up Generator starting. ""


that is the famous situation i ran into few time sure, sure , the tenents will cuss in very colourfull langunge some time it will show up in forgen langaune as well.

the last time it happend to me was a week ago one of the ground wire bump with netural wire that will trip the GFI system and i can heard the transfer switch kicked over to genny power i say [cussing in French ] oh well i have to reset the big 2500 amp 480 switch [ i have a chicken switch to do this for me ] to prevent flash over on me if something go wrong

Merci , Marc

P.S. if you plan to shut the main building power in large commercal area ya better plan that ahead of the time [ some will say heck no to this ]

You guys don't get out enough.
PLC's are industry these days.
I hope you guys aren't looking to change jobs soon.
I wouldn't employ you.

it's not what you need to know, but how you go about learning what you need to know. there is no doubt that you can do it. start as a 2nd or 3rd year apprentice. you will be making about the same amt of wages as a residential journeyman. try to find a journeyman with a least five years experience and willing to teach and do whatever it takes to stay with him. if you are big and strong and in good condition it will not be hard to find a adequate journeyman. don't try to hard, try not to talk to much and never talk about yourself. study print reading every chance you get. i am talking about construction prints from previous jobs the contractor has completed, they are always laying around, notice the as-builts, know the code and be able to pick out extras but try not to make the company estimators look bad, they are usually close to the owner, you don't want the estimators bad mouthing you, they are the moneymakers and carry a lot of weight, make them look good. get to know the estimators if possible. what you will find is new construction electricians may not be as adequate in troubleshooting as they should be so save your questions for the experienced troubleshooters when you get to get out on trouble calls. don't draw attention to yourself. if you start out as a journeyman you will put to much pressure on yourself and thats not good for anybody. outside instruction is fine in conjunction with an experienced journeyman but not as necessary as you might think. your desire will be fulfilled by how well you relate with the journeyman. if there is a large demand in your area for commercial electricians you have leg up because you are a journeyman and you can interview them, you are willing to work as an apprentice to learn from the ground up. go for it, commercial work is the entry way to being an industrial electrician and thats where you want to be in your twilight years when the arthritus sets in from those years as a residential-commercial wireman.

Mike I think that is a bit out of line.

Have you worked here in the US?

I can tell you there are plenty of competent electricians who work in industrial settings that never touch a PLC.

The factory I am currently assigned to has two on staff electricians. One is proficient with PLCs one is not.

I think it is worth pointing out that ShockMe77 was asking about commercial work, not industrial work.