code on transformer

[jhc8796]

Yes could someone tell me if there is a code on having to flex to a transfomer instead of hard pipe all the way for vibration or is it just a rule of thumb that most transformer are flexed?

 

[russ]

Re: code on transformer

Great question! I know of no code that requires you to use flex to tie in the feed or load of the transformer.
I suppose flex is used because the 90 degree connectors hug the transformer body.

Russ

 

[ron]

Re: code on transformer

You could transition to flexible metal conduit, MC or AC. There is no code requirement. Most projects designed by engineers, will have that requirement in the specification.

 

[templdl]

Re: code on transformer

It's a good practice as it reduces the transmission of noise that originates from the transformer.

 

[bennie]

Re: code on transformer

A 120 hertz hum will be heard all over the conduit system.

 

[ryan_618]

Re: code on transformer

Bennie: I'm certainly not as well versed in theory as you, but did say 120 Hertz? I thought 60.

 

[bennie]

Re: code on transformer

Ryan: Think of a cone in a speaker. The negative half and positive half will create a sound of 120 per second.

Put a rectifier on the 60 hertz wave. The output is 60 hertz pulsating DC. The speaker cone will move 60 times per second.

 

[ryan_618]

Re: code on transformer

Bennie: Thanks that makes a lot of sense.

 

[hbendillo]

Re: code on transformer

Bennie,
One cycle consist of the positive and negative part of the wave form. It is technically a 60 hertz hum, not 120.

 

[bennie]

Re: code on transformer

hbendillo: You are correct when describing a sine wave. However audio is different.

From an old Ham Radio Operator... The cone in a speaker, the membrane in your ear, and the laminations in a transformer, will vibrate once per half cycle. Therefore the vibration is at the rate of 120 times per second.

[ July 23, 2003, 04:57 PM: Message edited by: bennie ]

 

[brian john]

Re: code on transformer

bennie: Is this a 120 hertz hum or a 120 cycle hum? Or some other terminology in order?

 

[bennie]

Re: code on transformer

I suppose "irritating noise" will work.