Creepage Calculator for 24VAC

Thread Starter

DJ_AA

Joined Aug 6, 2021
15
Hi All

I am working on a PCB, which needs to provide 24VAC to various solenoids.
The max current each solenoid will require is about 0.3A-0.5A, but i would prefer to design for 1A.

On the PCB layout design I believe as its AC power a design would need to incorporate creepage.

Is this required for 24VAC?
 

Ian0

Joined Aug 7, 2020
3,459
The fact that it is an AC supply is irrelevant.
These are the values from EN60335 which applies to most household electronics.
1A7BEFB1-C6C8-4941-938C-65997B2D2EFE.jpeg
This is the pollution degree:
Pollution Degree 1: No pollution or only dry, nonconductive pollution occurs. The pollution has no effect.

Pollution Degree 2: Normally only nonconductive pollution occurs. Temporary conductivity caused by condensation is to be expected.

Pollution Degree 3: Conductive pollution or dry nonconductive pollution that becomes conductive due to condensation occurs. To be found in industrial environment or construction sites (harsh environments).

Pollution Degree 4: The pollution generates persistent conductivity caused by conductive dust, rain, or snow.

and the CTI for FR4 board is 175.
 

Thread Starter

DJ_AA

Joined Aug 6, 2021
15
I guess with 24V the spacing will be much lower then 50V,

At moment the spacing between my traces is about 3-5mm.
 

Ian0

Joined Aug 7, 2020
3,459
I guess with 24V the spacing will be much lower then 50V,
You're not allowed to interpolate the table, use the 50V values. Also check whether the voltage is rms or peak, and, obviously, if that standard applies to your product!
At moment the spacing between my traces is about 3-5mm.
So you can make your tracks wider until the spacing gets to 1.1mm
 

Thread Starter

DJ_AA

Joined Aug 6, 2021
15
Yes, it makes sense. This way maximise the current.

Would this spacing be between only 24VAC traces or 24VAC against any other nets?
 
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