Tuesday, March 3, 2009

[MW:1699] Re: 1680] Re :[MW:1671] Re: voltage

Hi Nilesh,
 
There is difference between the Arc Voltage and OCV.
 
When you strike the electrode or bring the electrode near to the material, if the gap is sufficient , the electrons started jump from the electrode tip to towards the material , that is why the voltage drops.
 
Put it otherwords, OCV will always higher than the Arc voltage (In OCV, there is large potential diffrence between -Ve and +Ve)
 
Still if you confused ; Please go throgh the Thermionic emission part in welding Hand book
 
Normally the electrodes designed to perform low OCV,
 
Thanks & Regards,
 
K.Babu M.E (Ind.Metallurgy)
Welding Engineer; PPL Shipyard Pte Ltd
Singapore
 
 

On Tue, Mar 3, 2009 at 9:02 AM, Chaitanya Purohit <ck@knm-group.com> wrote:

OCV for SMAW machine is 80 V generally…it varies machine to machine …. and quality of machine how it has maintained…..

 

Regards.

 

C. K. Purohit

General Manager - QC

KNM Process Systems Sdn Bhd - Malaysia

 

HP No. : 6016-3376448


From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Badrinath Raman
Sent: Monday, March 02, 2009 1:25 PM
To: materials-welding@googlegroups.com
Subject: [MW:1680] Re :[MW:1671] Re: voltage

 

For SMAW and GTIG we use Constant current power source and for MIG/SAW its constant voltage power source.
For MIG Arc Voltage is 20+0.4I (I is welding current)

Rgds
Badrinath Raman

On Sat, 28 Feb 2009 22:34:56 +0530 materials-welding@googlegroups.com wrote
Hi Nilesh,
 
The voltage before striking the arc is called open circuit voltage. and once we strike the arc, the current increases, voltage decreases and after that arc is maintained at sufficient arc gap and the voltage is termed as arc voltage.

 
Normally arc voltage during SMAW welding is kept at 24-27 volts and OCV shall not be higher. 
 
Mukesh 

 
On Sat, Feb 28, 2009 at 11:15 AM, nilesh parsekar wrote:



Dea All,
 
            I want to know what happens to the voltage when we strike the arc.Is it drops to zero and then gradually increases.
 
thanks
--
Nilesh Parsekar
Sr QC Co-ordinator
Exterran Belleli Energy
Fujairah - Sidem
Mobile - 0506561785

Shopping</Table


 





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