The T.M.Haja Sahib Transformer efficiency thread

Merry Christmas
Status
Not open for further replies.
T

T.M.Haja Sahib

Guest
I guess I thought a transformer wasn't suppose to be fully loaded? ?
Yes.Do not load it fully,if you do not have protective relays that would trip the transformer to prevent its loss of service life should its hot spot temperature rises above a certain limit.In the absence of such protective relays,you may safely load the transformer to 80% of its capacity.
 

iwire

Moderator
Staff member
Location
Massachusetts
Yes.Do not load it fully,if you do not have protective relays that would trip the transformer to prevent its loss of service life should its hot spot temperature rises above a certain limit.In the absence of such protective relays,you may safely load the transformer to 80% of its capacity.

That is just a design choice.

Transformers are designed for 100% loading and most power companies run them beyond 100% for short periods.
 

iwire

Moderator
Staff member
Location
Massachusetts
That is just a design choice.
It is not a design choice.:dunce:
It is a choice in the field.

Sorry no.

Electricians nor engineers do not typically determine the loading of a 500 kVA transformer 'in the field'. That is typically done by the engineering professional during the design phase of the project.

And next time you decide to insult with a dunce emoticon your post will be deleted.



Transformers are designed for 100% loading and most power companies run them beyond 100% for short periods.
Who denies it?

Who said anyone was denying it?
 
T

T.M.Haja Sahib

Guest
Electricians nor engineers do not typically determine the loading of a 500 kVA transformer 'in the field'. That is typically done by the engineering professional during the design phase of the project.

That would be true only if there are no future load additions.

And next time you decide to insult with a dunce emoticon .....

I did not mean any insult because you are my 'friend'.

Who said anyone was denying it?

post#8
 

iwire

Moderator
Staff member
Location
Massachusetts
That would be true only if there are no future load additions.

The code requires calculations be done when loads area added, in many areas these calculations must be done by an engineer.

Now of course loads do get added without regard for the transformer loading but I try to confine my worries to what is allowed and not what people may do. If we worry about what people may do to an electrical system after we leave we would never get anything done.



I did not mean any insult because you are my 'friend'.

We are not friends.




I don't play that game, either post it or forget it.
 
T

T.M.Haja Sahib

Guest
The code requires calculations be done when loads area added, in many areas these calculations must be done by an engineer.

Now of course loads do get added without regard for the transformer loading but I try to confine my worries to what is allowed and not what people may do. If we worry about what people may do to an electrical system after we leave we would never get anything done.

Spare capacity in any electrical system including a transformer is an engineering requirement.From that point of view,the field people may legitimately load the transformer the way they want it.

We are not friends.

Why not?:)
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Spare capacity in any electrical system including a transformer is an engineering requirement.From that point of view,the field people may legitimately load the transformer the way they want it.
It is a design issue, not a code issue to have spare capacity. There in no reason to expect that an existing system has spare capacity. The field people that are adding load are required by code to verify that there is capacity to support the new load.
 

bob

Senior Member
Location
Alabama
And next time you decide to insult with a dunce emoticon your post will be deleted.

Looking at the :dunce: I did not realize it was a dunce reference until you pointed it out.
If that is true, it should be removed so that it can never be posted again.
 
T

T.M.Haja Sahib

Guest
......not a code issue to have spare capacity. There in no reason to expect that an existing system has spare capacity......

That is the crux of the question of this thread.Sec 90-1(B) states about the adequacy i.e spare capacity to be built into the electrical system but it is just a recommendation and not a requirement.If any code proposal is able to change it to a requirement,a clear cut answer to this thread not only becomes possible but also greater value to the code itself.
 

iwire

Moderator
Staff member
Location
Massachusetts
Looking at the :dunce: I did not realize it was a dunce reference until you pointed it out.
If that is true, it should be removed so that it can never be posted again.

Not to get to far off topic but I have used it for myself when I goof up.

Like most anything the context in which it is used makes all the difference. :)
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
That is the crux of the question of this thread.Sec 90-1(B) states about the adequacy i.e spare capacity to be built into the electrical system but it is just a recommendation and not a requirement.If any code proposal is able to change it to a requirement,a clear cut answer to this thread not only becomes possible but also greater value to the code itself.
I don't see any value in a code rule that would require the owner to install excess capacity. That should remain a design issue and not a NEC requirement.
 
T

T.M.Haja Sahib

Guest
If there is no enforcement of spare capacity by the code,people tend to do what they want as of now:conduits tend to overfill,transformers tend to be overheated and so on and on.
 
Last edited:

iwire

Moderator
Staff member
Location
Massachusetts
If there is no enforcement of spare capacity by the code,people tend to do what they want as of now:conduits tend to overfill,transformers tend to be overheated and so on and on.

How can you enforce spare capacity?

What good is spare capacity if you can not use it because the code requires you have some?
 

kwired

Electron manager
Location
NE Nebraska
Spare capacity in any electrical system including a transformer is an engineering requirement.From that point of view,the field people may legitimately load the transformer the way they want it.



Why not?:)

How are we to know how much spare capacity to be prepared for? Would we then need to increase capacity when we use up the spare capacity so there is more spare capacity again? What if we have 600 amp service - with 200 amps of spare capacity, then owner decides to put on addition that requires 800 amps of capacity for the addition alone? What good did that extra 200 on the original installation do for us?

The :dunce::dunce::dunce: is approiate for some situations IMHO.

Usually not when addressing other forum members. Addressing a DIY or handyman yes.
 
Status
Not open for further replies.
Top