Panel Schedules - What are they for?

[kingpb]

I have been trying to revamp and develop an automated type panel schedule for three phase panels.

In doing so I'm trying to think outside the box so to speak, and question exactly what is the panel schedule's intent? What information is really important, i.e. to the designer, installer, owner, building department.

There are so many different one's out there that I have seen over the years, but based on a wide degree of exposure (this forum) what info is really needed, and why is it needed?

Let this be a pandora's box, there are no right or wrong opinions, I want to here all sides.:thumbsup:

 

[charlie b]

Why, the purpose is to comply with 408.4, of course. What else can there be?

OK, since I am guessing the question was serious, here is my serious, two-part answer.

First, I think the intent of 408.4 is to give the user, and a future maintenance person, a basic notion of what would be turned off by what breaker. That is the only actual requirement.

Secondly, as a design engineer, I use panel schedules as my method-of-choice for performing load calculations, and to demonstrate (e.g., to a plan reviewer) that no panel will be overloaded by my design. This works best for new buildings, but has come in handy for renovations. The information I need, in order for this to be an effective tool, includes the following:

• Panel ratings (i.e., voltage, full load current, short circuit current, phases, # wires).
• Panel name and location.
• Rating of main breaker, or statement that panel is MLO.
• For each circuit number, the number of phases and current rating of the breaker.
• For each circuit number, the load (in KVA) on each phase.
• For each circuit number, the type of load (e.g., lighting, receptacle, motor).
• The sum of the KVA loads on each phase, and the total KVA ?connected load? on the panel.
• Where appropriate, the application of a demand factor to the KVA load of any specific item (i.e., 125% for the largest motor, or 50% of receptacle loads over 10KVA).
• The total ?demand load? of the panel, in KVA.
• The equivalent of the demand load, in amps.

The spreadsheet I use (created over many years by a friend and former colleague) has the following additional features (and before anyone asks, I am not at liberty to send anyone a copy):

• It gives me a warning notice, if I forget to assign a load as being lighting, receptacle, or some other type.
• It gives me a warning notice, if I have added too much load to the panel (i.e., exceeded the rating that I had assigned).
• It allows me to declare a load as being non-coincident with another (e.g., back up pump motors), so that its load is not added to the total demand load.
• It has pull-down menus for voltage ratings, main breaker ratings, and a few other items.
• It can link all the branch panel loads to the distribution panel that feeds the branch panels, and link the distribution panels to the main service panel. Thus, it actually does perform the service load calculation for me.
• It is ?smart? enough to figure out which ?largest motor? on all the branch panels served by the same distribution panel is the largest of the group, and on the distribution panel?s demand load it only assigns the 125% factor to that one motor. It can do the same at the main service panel.

 

[Little Bill]

Charlie, you're way over thinking this.
This is the way most people label their panels and is what we as electricians are used to.

1.- lights

2. plugs

3. AC -I think

4. " "

5. 220 stuff

6. " "

7. Grandma's b.room

8. Some other plugs

9. Attic, 1 of the bedrooms, side room

10. Unknown stuff around the house

11. The plugs with that push button thing on it.

Simple & Effective (Not) :lol:

 

[charlie b]

Charlie, you're way over thinking this.

Not really. As I said, to me a panel schedule is a design tool, not just a label located inside the panel door.

 

[weressl]

Charlie, you're way over thinking this.
This is the way most people label their panels and is what we as electricians are used to.

1.- lights

2. plugs

3. AC -I think

4. " "

5. 220 stuff

6. " "

7. Grandma's b.room

8. Some other plugs

9. Attic, 1 of the bedrooms, side room

10. Unknown stuff around the house

11. The plugs with that push button thing on it.

Simple & Effective (Not) :lol:

You need to get out sometimes and explore the World outside of that little box that the above represents.:roll:

 

[weressl]

Not really. As I said, to me a panel schedule is a design tool, not just a label located inside the panel door.

...and the following:

1. Maintenance tool,
2. Safety information as required by OSHA,
3. Operational tool.

 

[Little Bill]

Not really. As I said, to me a panel schedule is a design tool, not just a label located inside the panel door.

Charlie, that was my attempt at a little humor, but we do see descriptions like that out in the field. Your panel schedule is great, don't take me so serious.

 

[dhalleron]

I have always thought the printed or hand written panel schedule on the door is a waste of time and effort.

They sometimes work if you need to turn off the air conditioner or dryer, but there is not enough room to list everything that is controlled by each breaker. When I need to turn off a lighting circuit in house, I end up flipping several breakers even on a well marked panel.

I have only been in a few homes with the perfect schedule. It usually belonged to some old guy who took the time to draw a floor plan and label every outlet as to which breaker it controlled. I even worked at a retired army colonel?s house that had labels engraved for all of his light switches to let him know what they controlled.

 

[PEDRO ESCOVILLA]

i used to write the circuit number on the back side of the faceplate so who ever was coming in behind me for what ever reason knew where the circuit was really fed from (#, panel, etc.)

 

[kingpb]

Charlie,
How do you account for 2-pole loads on a 3 phase panel?

If stating the total KVA, by using the KVA of each phase, and then divide by voltage and sqrt 3 to get current, it will be under assumption that all phases are balanced. A 3ph panel with a bunch of 2pole loads could have some error by calculating current that way, or the current in one phase could be greater than the value calcuated using total 3phase.

Is it assumed that the error is at an acceptable level for the intended use?

 

[hockeyoligist2]

i used to write the circuit number on the back side of the faceplate so who ever was coming in behind me for what ever reason knew where the circuit was really fed from (#, panel, etc.)

I wish everyone would do that! I have spent so many hours trying to find out where the breakers are on machinery. I will have a pump or something sitting out in between 3 or 4 buildings and not know where it is fed from. Look at the schedules on every box and nothing matches and/or it will be labeled MAU301 and the other end is labeled XYZ205. I can't just start flipping off breakers till I find the right one.

Another thing I am still trying to figure out a breaker on an MCC that is labeled Lime feed pump #2. We only have 1 at that plant and this breaker has a dead short on all 3 legs! The drawings don't help a bit either. I disconnected it and told them to call me back if something wasn't working, that has been over a month and no call yet!

 

[charlie b]

Charlie, How do you account for 2-pole loads on a 3 phase panel?

I always enter the loads in units of KVA. For example, if I have a two-pole, single phase, 500 VA load connected between phases A and B, then on each phase I show a load of 0.25 KVA. The math works fine from that point.

After I have entered all the loads, I will look at the balancing among the phases. Sometimes I will reassign loads to different circuits, in order to improve the "design" balance. We all know, however, that we can't control which loads are turned on at any given moment. So there will be unbalance among the phases in actual service, whatever we try to do.

 

[charlie b]

i used to write the circuit number on the back side of the faceplate so who ever was coming in behind me for what ever reason knew where the circuit was really fed from (#, panel, etc.)

Some of my clients actually require that. My problem with the concept is that the next time the room gets painted, all the faceplates will be removed, and good luck getting each one back at the right location. :slaphead:

 

[K8MHZ]

I have always thought the printed or hand written panel schedule on the door is a waste of time and effort.

They sometimes work if you need to turn off the air conditioner or dryer, but there is not enough room to list everything that is controlled by each breaker. When I need to turn off a lighting circuit in house, I end up flipping several breakers even on a well marked panel.

I have only been in a few homes with the perfect schedule. It usually belonged to some old guy who took the time to draw a floor plan and label every outlet as to which breaker it controlled. I even worked at a retired army colonel?s house that had labels engraved for all of his light switches to let him know what they controlled.

I am toying with the idea of using 3 x 5 cards, one for each breaker. The trick, of course, would be to figure out some way to attach the cards....but if you could, there would be plenty of room to list every outlet plus room for future revisions.

 

[blargh]

I am toying with the idea of using 3 x 5 cards, one for each breaker. The trick, of course, would be to figure out some way to attach the cards....but if you could, there would be plenty of room to list every outlet plus room for future revisions.

The problem I see is not so much "space to list everything", but the ability to clearly and concisely label the locations of all the different outlets. How do you differentiate between different bedrooms, for example, in a way that's going to make sense to anyone besides yourself.

I think a floorplan is one of the best ways to approach it, but most people aren't up for that level of effort.

 

[GearMan]

I have been trying to revamp and develop an automated type panel schedule for three phase panels.

In doing so I'm trying to think outside the box so to speak, and question exactly what is the panel schedule's intent? What information is really important, i.e. to the designer, installer, owner, building department.

There are so many different one's out there that I have seen over the years, but based on a wide degree of exposure (this forum) what info is really needed, and why is it needed?

Let this be a pandora's box, there are no right or wrong opinions, I want to here all sides.:thumbsup:

Got an idea. We get NEMA together to add a chip to all MCCB's to collect data. charlie b and his friend can do the load calc's on his spread sheet, include the electronic data in the plans. The quotation guys can download to the Mfg estimating software, upload the coded panel schedules at time of order entry. The plant places the cb's as coded and includes a panel schedule chip & ships to jobsite. On site the contractor can simply view the schedule from his iPad. Moving the breakers around will automatically update the panel schedule chip. Keep the vision alive. In memory of Steve Jobs.*

 

[zbang]

One thing that most people miss is the date, especially for a printed schedule in a changing environment. I want to know how old it is so I can guess how much to trust it. Heck, it there's space, I'll jot down the date when I change something. Might help the next person.

Lime pump #2? Maybe somebody installed wire for future use and nutted all the wires together at the j-box. That's just a WAG.

 

[K8MHZ]

The problem I see is not so much "space to list everything", but the ability to clearly and concisely label the locations of all the different outlets. How do you differentiate between different bedrooms, for example, in a way that's going to make sense to anyone besides yourself.

I think a floorplan is one of the best ways to approach it, but most people aren't up for that level of effort.

You mean like:

BKR 28 - Dog room by chair

 

[scott thompson]

Panel Schedules as Design Tools

Panel Schedules as Design Tools

My Panel Schedules are quite similar to Charlie's, per his descriptions above - with a few more Tweaks...

A: To incorporate all into a complete form, the individual Panel Schedule Spreadsheets may be linked to a "Master" Spreadsheet, which is the Service Equipment Schedule. If Distribution Sections are involved, Panelboards link to the Distribution Panels, and the DPs link to the Service Section.

B: If a Panelboard is fed via SDS Transformer, the Spreadsheet(s) have a Tab for feeding through Transformers, and allow linking to another Panelboard (or DP Section), for the Primary Circuit.

C: Each individual Panel schedule Spreadsheet has a Tab for a Circuit Directory Card. Information is Auto-Filled during base Data Entry.

D: Each Panel Schedule Spreadsheet includes Fault Calculation and Voltage Drop Calculation, automatically configured with Data Entry.

E: The complete Workbook tracks and records changes, so as to update Loads as needed, and to identify revisions for an Audit Trail.

F: Each Spreadsheet has a Graphical Database, which is embedded to AutoCAD Schedule Files (for display in the Planset), and may be Printed as PDFs, for distribution.

G: Each Spreadsheet has a Tab for a B.O.M. output (running Bill Of Material) for Estimation usage.

H: The "Master" Sheet has a Tab for OLE to the Single Line Diagram (still working bugs out of this).

These are all custom Excel Spreadsheets I have built over many Years. They save lots of time and effort, and reduce errors as well (after debugged!).
Suggest anyone involved with Designs to compile your own Spreadsheets.
Try to keep them "User friendly". Mine our so far from "User Friendly", that even the geekiest Guy at the Office cannot figure out how to use them!

-- Scott

 

[Cow]

I think half the battle with panel schedules is laying out circuits in an orderly manner. I've had guys working with me that say we'll just throw that on with so and so breaker, etc. I usually ask them how will we label that breaker using one line on a panel schedule card when we need a paragraph to explain all the random equipment/locations on that circuit?

One example, group your circuits by location, don't jump through a whole building throwing these receps on with these ex. fans or these lights, etc just because the circuit can handle it. I can usually design circuit layout fairly systematically without a whole bunch of lightly loaded circuits(just for the sake of panel scheduling!) while still keeping everything as common sense as possible.

I personally hate when I see these descriptions in panels:

lights and receps
xyz's office
old copier
new copier

Things change, people leave their companies. I like N, S, E, W designations. There's no screwing that up.

I guess this really didn't answer the OP's question, got a little side tracked here...