Vibration

[Wire_nutz]

Hard piped or flexed?

I see larger transformers such as 115 KVA that are hard piped directly to the transformer and ones that are connected with a flexible means. Larger transformers have vibration pads on the frame with bolts that must be loosened before being energized.

What does the code say about vibration?

What are some good examples of excessive vibration when some electrical device must be connected with a flexible means rather than a solid hard pipe method?

 

[iwire]

As far as I know the NEC does not require we do anything about vibration.

 

[One-eyed Jack]

It would have more to do with customer satisfaction.

 

[Wire_nutz]

As far as I know the NEC does not require we do anything about vibration.

If there is no NEC rule than it would just be preference

 

[iwire]

It would have more to do with customer satisfaction.

I agree.

If there is no NEC rule than it would just be preference

Or a job specification.


In quiet areas I would be concerned about vibration and use flex, on the other hand in a noisy mechanical room I may hard pipe in if it is easier, sometimes wireway.

 

[ohmhead]

Well thats a new one on me i have never seen a hard piped transformer ever please do you have a picture post it ?

The factory has vibration pads internal but most transformers loaded with hum and transfer that thur the pipes this to me is just plain common sense to use flex indoors or sealtite outdoors .

Most jobs we see are called out rubber cork pads by weight for that transformer in addition to whats inside we put these on the house keeping pad and use a bolt & lag .

And on real high profile work we must use vibration springs which are a joke to install but the engineers think there doing something good .

Ill locate a picture of one for laughs these were so high that if you touched the transformer it would move so far the inspector said to take them off for safety reasons the engineer was a little upset and agreed .

I guess iam getting old but i have never seen a motor or a trans hard piped .

 

[Wire_nutz]

Well thats a new one on me i have never seen a hard piped transformer ever please do you have a picture post it ?

The factory has vibration pads internal but most transformers loaded with hum and transfer that thur the pipes this to me is just plain common sense to use flex indoors or sealtite outdoors .

Most jobs we see are called out rubber cork pads by weight for that transformer in addition to whats inside we put these on the house keeping pad and use a bolt & lag .

And on real high profile work we must use vibration springs which are a joke to install but the engineers think there doing something good .

Ill locate a picture of one for laughs these were so high that if you touched the transformer it would move so far the inspector said to take them off for safety reasons the engineer was a little upset and agreed .

I guess iam getting old but i have never seen a motor or a trans hard piped .

I did not mention Motor in the post. But I have seen many hard piped transformers!

 

[ohmhead]

I did not mention Motor in the post. But I have seen many hard piped transformers!

Well i stand corrected Wire- nutz i know you didnt but maybe someone has done that also so i asked the question .

I guess ill look into this more i know a transformer from the factory has its own V pads inside but i just have always seen the addition of added pads under a transformer frame and most job specs called for this its always shown on the detailed drawns of the transformers on every job .

And also flex on every detail

I see i have just learned something new today wow .

 

[iwire]

but i just have always seen the addition of added pads under a transformer frame and most job specs called for this its always shown on the detailed drawns of the transformers on every job .

Yeah we get that as well in office jobs where noise is a problem.


On the other hand if a room has a dozen refrigeration compressors running the additional vibration of a transformer is not an issue. It is very nice when you can run out of a switch board with 12" x 12" trough right into the side of a transformer. The conductors go in much easier.

 

[RUWired]

Well thats a new one on me i have never seen a hard piped transformer ever please do you have a picture post it ?

Here is one that does'nt have any noticeable noise or vibration.

View attachment 4138

 

[DARUSA]

Here is one that does'nt have any noticeable noise or vibration.

View attachment 4138

Wich brand is that LB ? Look like it is long enought to meet the angle pull requirements!!!

 

[qcroanoke]

Wich brand is that LB ? Look like it is long enought to meet the angle pull requirements!!!

I think it's called a mogul but I don't think that's the brand just the type.

 

[Ragin Cajun]

It looks like the transformer is mounted hard up against the back wall - a real no-no for cooling. Cuts down ~50% of the ventilation.

RC

 

[RUWired]

Yes it is close maybe 3 inches. my job was to refeed with em source. transformer been there for many years. we.ll call that existing condition. the lb is a killark mol900. 24 inches between raceways.