computer loads and a stickler Inspector

[Mr. Bill]

I've already searched thru the forums here and found info about common practice but not NEC to the letter of the law.

1) Per NEC 220.14(A) am I required to use the nameplate rating on a CPU and monitor for sizing of the branch circuits? Nameplate CPU reads 5A at 120V and monitor reads 2A at 120V. 5A + 2A = 7A. Inspector is not giving occupancy until circuits are added so no more than 2 computers are on any 20A branch circuit. I know CPU usage is dramatically lower than nameplate rating but this Inspector is going by the nameplate.

2) Does an Inspector have authority to control what is plugged into a receptacle?

3) Do I have recourse to go after this Inspector if I find out he enforces this rule on some projects but not on others? If it's significant enough to withhold occupancy then he must consider it very important. If he's not enforcing this on other projects then he's endangering the public and I could talk to his bosses about diciplinary actions.

This Inspector has a reputation for being difficult. Most everyone seems to bend over backward to placate him. From my experience, in the long run that only emboldens the Inspector. So I'd like to attack the bully by following the letter of the law as he so often likes to. I'd appreciate any help.

 

[ASG]

Why is the nameplate rating so high? What kind of computers are these?

 

[cowboyjwc]

1) Remember nothing says that you are limited to the amount of receptacles that you can put on a circuit, so how could you control what's plugged in?

2) NO!

3) As my father once told me, "everyone has a boss." How high you're willing to climb and how long you're willing to fight is up to you. That comes from me.

 

[chris kennedy]

1) Per NEC 220.14(A) am I required to use the nameplate rating on a CPU and monitor for sizing of the branch circuits?

Its a receptacle in other than dwelling unit, no? 180va as per 220.14(I).

 

[Jim W in Tampa]

Call him down on this one. First tell him you want a code number. Actually if its holding up moving in call his boss and the county lawyer and give them 24 hours before you file law suit at $500 a day for loss of use. You don't have an inspector you have a jack----. And he needs fired. He can not control the use of receptacles other than items in place that require a dedicated circuit.

 

[ceb58]

Its a receptacle in other than dwelling unit, no? 180va as per 220.14(I).

Chris is right. It works out at 1.5amps per recpt. so 12 recpt. would be 18amps. If it were a dwelling you could put 1000 recpt. on it.

 

[kwired]

I've already searched thru the forums here and found info about common practice but not NEC to the letter of the law.

1) Per NEC 220.14(A) am I required to use the nameplate rating on a CPU and monitor for sizing of the branch circuits? Nameplate CPU reads 5A at 120V and monitor reads 2A at 120V. 5A + 2A = 7A. Inspector is not giving occupancy until circuits are added so no more than 2 computers are on any 20A branch circuit. I know CPU usage is dramatically lower than nameplate rating but this Inspector is going by the nameplate.

2) Does an Inspector have authority to control what is plugged into a receptacle?

3) Do I have recourse to go after this Inspector if I find out he enforces this rule on some projects but not on others? If it's significant enough to withhold occupancy then he must consider it very important. If he's not enforcing this on other projects then he's endangering the public and I could talk to his bosses about diciplinary actions.

This Inspector has a reputation for being difficult. Most everyone seems to bend over backward to placate him. From my experience, in the long run that only emboldens the Inspector. So I'd like to attack the bully by following the letter of the law as he so often likes to. I'd appreciate any help.

Better hope this guy doesn't look at nameplate on a laser printer, or see the heater that gets brought in when the secretary gets cold feet in the winter time.

220.14(I) says 180 VA per receptacle.

220.14(A) says An outlet for a specific appliance or other load not covered in 220.14(B) through (L) shall be calculated based on the ampere rating of the appliance or load served.

220.14(K) may possibly apply to the OP says the larger of:
(1) The calculated load from 220.14(I)
(2) 11 volt-amperes/m2 or 1 volt-ampere/ft2

Part 2 of this does not give us VA value per outlet.

If inspector is citing 220.14(A) the outlet had better be intended for a specific appliance (the computer). Unless the receptacle is marked to indicate that the computer is to be the only device plugged in, how can one call it anything but a general purpose outlet?

When using part 2 of 200.14(K) in most cases you will still have a larger value at a workstation area with the part 1 figures.

 

[hurk27]

I have never seen this type of call before, but all I can put together from the NEC is this:

210.11(A) Number of Branch Circuits. The minimum number
of branch circuits shall be determined from the total calculated
load and the size or rating of the circuits used. In all
installations, the number of circuits shall be sufficient to
supply the load served. In no case shall the load on any
circuit exceed the maximum specified by 220.18.

220.18 Maximum Loads. The total load shall not exceed
the rating of the branch circuit, and it shall not exceed the
maximum loads specified in 220.18(A) through (C) under
the conditions specified therein.

If there is a de-rating factor for computers I can't find it, but it appears above that the limit on a circuit is the rating of the circuit which is 20 amps, and 3 computers @7 amps is 21 amps, but we all know they will not ever come close to ever drawing this, to speed up getting the Occupancy, I would ask the customer to remove the extra computers until after the final? or explain to them that since the loads were not known at the time of the bid, you will have to submit a change order to install the extra circuits.

I always state in my contract that if equipment is installed before the final which results in a code infraction, a change order will be issued and the changes will be done on a time and material bases.

best I can come up with

 

[TOOL_5150]

Why is the nameplate rating so high? What kind of computers are these?

Thats very typical for a multi core computer these days.

~Matt

 

[kwired]

Thats very typical for a multi core computer these days.

~Matt

And it is likely not a continuous load rating either, but instead a peak load rating.

 

[TOOL_5150]

And it is likely not a continuous load rating either, but instead a peak load rating.

Agreed, The PSU may not be loaded to the max either, or it could be. Best thing to do in the case of a bunch of computers - do an actual amp clamp reading.

~Matt

 

[Jim W in Tampa]

"210.11(A) Number of Branch Circuits. The minimum number
of branch circuits shall be determined from the total calculated
load and the size or rating of the circuits used. In all
installations, the number of circuits shall be sufficient to
supply the load served. In no case shall the load on any
circuit exceed the maximum specified by 220.18.

Quote:
220.18 Maximum Loads. The total load shall not exceed
the rating of the branch circuit, and it shall not exceed the
maximum loads specified in 220.18(A) through (C) under
the conditions specified therein.


The load is not known and name plates only show the Max.
If we use name plates we are in big trouble. We could sit a coffee maker, 4 slice toaster, blender , toaster oven all on 1 section of kitchen counter on 1 circuit. That adds up to far more than 2400 watts. They seldom if ever would all be used at same time.
Does this inspector add up every load in the house ? Your 200 amp service will not cover it.
You have an inspector that is clueless and misreading codes. If for some reason there is an overload then so what the breaker trips. Problem is yours and customers not the inspectors.
If you must play games with him then do so and remove the items till ink dries.
You should not put up with him and if all electricians complain about him chances are high he will go away.

 

[pfalcon]

Careful on the inspector bashing. The OP already cites that the outlets will be used for a specific load - two computers with monitors. If that is verified then 220.14(A) seems to apply; ampere rating not amp clamp or use derating.

 

[growler]

Inspector is not giving occupancy until circuits are added so no more than 2 computers are on any 20A branch circuit. I know CPU usage is dramatically lower than nameplate rating but this Inspector is going by the nameplate.

This is not really a safety issue. You have 20 Amp circuit (conductors ) being protected by a 20 Amp breaker so the worst that should happen is that a breaker will trip and perform it's designed function.

But from an engineering standpoint what amperage did you use to calculate the load per circuit and how did you obtain this information? If the breakers do start tripping you would have some unhappy customers.

I think the first thing I would do is check the current draw and see if he does maybe have a point. If it looks like the circuits are overloaded it would be better to catch it early. If things appear to work fine I would supply the inspector with this information.

I think having any documentation of how the load was determined would going a long way to make the inspector feel better.

 

[cowboyjwc]

And this is a good example of why you should never give C of O until after everything is finaled.

 

[jxofaltrds]

There is nothing in the code that allows an inspector to 'guess' what you may or may not do in the future.

Unplug everything and call for a re-inspection.

Now that everything is unplugged ask him what you are allowed to plug into these receptacles. Give him a list of all the office equipment and ask him to design the placement of the equipment. See where I am going?

Not his concern.

 

[Mr. Bill]

Why is the nameplate rating so high? What kind of computers are these?

The CPU under my desk is labeled at 6A. Check your's. This is a worst case, all drive slots are used and running at peak.

1) Remember nothing says that you are limited to the amount of receptacles that you can put on a circuit, so how could you control what's plugged in?
The Inspector is not questioning the number of receptacles.

2) NO!
If it's not in writing somewhere then I cannot convince him of this.

Its a receptacle in other than dwelling unit, no? 180va as per 220.14(I).

And that is how I have always based circuit loads in the past. His arguement is that if the outlet is located where the intended load is a specific appliance (computer) then 220.14(A) is more applicable then (I) or (L).

Call him down on this one. First tell him you want a code number. Actually if its holding up moving in call his boss and the county lawyer and give them 24 hours before you file law suit at $500 a day for loss of use. You don't have an inspector you have a jack----. And he needs fired. He can not control the use of receptacles other than items in place that require a dedicated circuit.

We're seeing how it goes today with the computers unplugged. I agree he needs to be either fired or knocked off his high horse. A lawsuit is unlikely since Inspectors and the State are not legally liable for their interpretation of the Code.

I have never seen this type of call before, but all I can put together from the NEC is this:
220.18 does not appear applicable because these loads are not specified in (A) thru (C).
If there is a de-rating factor for computers I can't find it, but it appears above that the limit on a circuit is the rating of the circuit which is 20 amps, and 3 computers @7 amps is 21 amps, but we all know they will not ever come close to ever drawing this, to speed up getting the Occupancy, I would ask the customer to remove the extra computers until after the final?
We are unplugging the excess computers and seeing what he says. I'm expecting this will go to his boss.

best I can come up with

"210.11(A) Number of Branch Circuits. The minimum number
of branch circuits shall be determined from the total calculated
load and the size or rating of the circuits used. In all
installations, the number of circuits shall be sufficient to
supply the load served. In no case shall the load on any
circuit exceed the maximum specified by 220.18.

Quote:
220.18 Maximum Loads. The total load shall not exceed
the rating of the branch circuit, and it shall not exceed the
maximum loads specified in 220.18(A) through (C) under
the conditions specified therein.
220.18 does not appear to be applicable to computer loads. If it is then the arguement is how is the load defined in VA.

The load is not known and name plates only show the Max.
If we use name plates we are in big trouble. We could sit a coffee maker, 4 slice toaster, blender , toaster oven all on 1 section of kitchen counter on 1 circuit. That adds up to far more than 2400 watts. They seldom if ever would all be used at same time.
I wouldn't put it past him.
Does this inspector add up every load in the house ? Your 200 amp service will not cover it.
Service sizes can be derated based on other section of the Code. Article 220 is for branch circuits.
You have an inspector that is clueless and misreading codes. If for some reason there is an overload then so what the breaker trips. Problem is yours and customers not the inspectors.
If you must play games with him then do so and remove the items till ink dries.
You should not put up with him and if all electricians complain about him chances are high he will go away.
He's been around for years. I don't know what the likelyhood is of him going away.

There is nothing in the code that allows an inspector to 'guess' what you may or may not do in the future.

Unplug everything and call for a re-inspection.

Now that everything is unplugged ask him what you are allowed to plug into these receptacles. Give him a list of all the office equipment and ask him to design the placement of the equipment. See where I am going?
He says there are X computers and Y circuits in the room. X/Y is greater than 2 computers per circuit therefore it is a Code violation.
Not his concern.
He seems to think it is.

 

[Mr. Bill]

I'm basing my standing right now on

80.1. Scope. The code regulates the design, installation, maintenance, alteration, and inspection of electrical systems including all wiring, fixtures, appliances, and appurtenances in connection with the utilization of electrical energy, within or on a building, structure, or properties, and including service entrance wiring as defined by the code.

If it?s not plugged in he has no Authority over it.

The link is here.
http://www.michigan.gov/documents/d...e_rules_part8_2008_print_version_295688_7.pdf

 

[weressl]

The CPU under my desk is labeled at 6A. Check your's. This is a worst case, all drive slots are used and running at peak.




And that is how I have always based circuit loads in the past. His arguement is that if the outlet is located where the intended load is a specific appliance (computer) then 220.14(A) is more applicable then (I) or (L).


We're seeing how it goes today with the computers unplugged. I agree he needs to be either fired or knocked off his high horse. A lawsuit is unlikely since Inspectors and the State are not legally liable for their interpretation of the Code.

A dwelling is for personal use. Are we going to regulate how individuals are going to utilize their home? Are we supposed to be safe and secure and immune to unwarranted searches and intrusions in those places?

An electrician - or designer - gives its best efforts to decide how many general use receptacles will there be for each circuits and then properly protect that based on the maximum load one outlet can handle. As it was pointed out if it is overloaded on either a single outlet or the sum of the outlet loads, it will trip. It is safe and that IS the main goal of the NEC. Unless it is either permanently wired there is no way to determine what will be plugged into that circuit by the user.

One of the silly examples is the receptacle for refrigerators in the garage. It does not need to be GF protected. So what will happen if the user decide to plug his planer into it? Will the Grand In(qui)spector make unscheduled visits - called raids - to check on the property that it is utilized in a way that is contrary how he approved? Hardly, without a search warrant.....

 

[480sparky]

So what will the inspector do if you make one computer go away?

And what happens when someone plugs in a 1500W space heater after inspection?