QUERY - Cellulose electrode and PEGAS 200 T HF PULSE

[marek]

Hello local experts

I own this welder and would like to ask whether I can use it for welding cellulose electrodes ? Or what type . Thank you for your answers. Here is a link to the aforementioned welding inverter -

http://www.alfain.eu/dokumenty/002/pegas_160_200_t_pulse_hf.pdf

It is a model - PEGAS 200 T PULSE HF

 

[Rrunnach]

Don't think so, you need 80 OCV, where as, your machins has a max of 65 OVC.

 

[Drains]

There are some cellulosics (see Fleetweld 180 here) which can run on lower voltages. 6011s generally seem to be able to be used on a wider range of sets (not least, AC)

You'll need to get on touch with some suppliers and ask what OCV are required. Don't assume that machine won't do cellulosics, but be sure it won't do all of them!

 

[marek]

Thank you for your feedback and comments. I was just a bit taken aback that the inverter would not not go cellulose electrode . Check out this link - http://www.wtl.com.cn/ShowProduct_e.aspx?ID=197
Tento invertor má napětí naprázdno jen 64V! a přesto je podle návodu schopen svařovat celulosovou elektrodou - 6011

 

[TechnicAl]

Cellulosics run better on DC (even 6011s). I can never understand who or why anyone would run one on AC.
The OCV only affects AC operation.

 

[Drains]

The OCV only affects AC operation.

I've been going on the assumption that some DC sets - eg lower OCV inverters - couldn't run all cellulosics. Mind you, rod packets do normally only specify voltage on AC, so I guess Al, you must be right!

That's a cue to try some 6011s on different inverters tomorrow...

 

[marek]

I found that welder for 7018, 6013 is steep characteristics - constant current welder and for 6010, 6011 is a semi step characteristics - constant power
problem ???

 

[zst]

Is there needed different "working voltage" for cellulosic electrodes

Cellulosic electrodes request high OCV, someone told over 80V.
But, are they ask for higher "working voltage" too?
I saw, at present SMAW machines, working voltage is determined as V=20+0.04*A (A=amperage).
Some SMAW machines are specially made for cellulosic electrodes, such as some Fronius machines.
Does someone know if they have higher "working voltage" than one described with above formula or the point is just in strong "arc-force" for digging effect to produce high penetration in root, while welder push the tip of electrode in root gap?

 

[SiPMerlin150]

A more experienced member will be along to answer your question,
but most cellulosic electrodes run on DC with OCV of 70v+

Arc force is a setting on the machine that allows you to keep a very short arc length without risk of experiencing voltage? (am I right?) drop and causing the arc to extinguish, and sticking your rod of to the work. It beefs up the current in these situations and will aid in penetration. Too much arc force will make the electrode cut through metal like a gouging rod.

 

[SiPMerlin150]

'A more experienced member will be along to answer your question',


Wow by the time I published this, there was 4 extra replies!

 

[Drains]

ZST, I remember someone on UKWelder years ago who had done a voltage test of different rod types and finding big variations for the same diameter rods with different fluxes. I can't remember where cellulosics came on working voltage but it was quite different to the others. The point being (it seemed) that the working voltage was a product of the flux, not the output of the welder.

 

[PTvor]

Usually inverters have fancy features such as detecting open circuit and then when the rod touches the metal, throwing everything at it for a few milliseconds to establish the arc, and then easing back to the set welding current . Hot start.

However, the makers almiost always specify an OCV for the inverter and a list of the rods it can burn. Mild steel, basic, stainless.

If inverters can deal with cellulosics it tends to be a feature the makers stress in the blurb. I don't believe there's a strict relationship between the machine's OCV and its ability to burn cellulosics.

It's a thing I would like to know the answer to.

The fact is that most people (in the UK at least) are perfectly happy with a machine that has a smooth DC arc and can strike and burn just about any rods commonly found. Celluosics are something which if you've got to use them, someone else is paying for them and the machine.

 

[zst]

What I could remember from some seminars:
Cellulose is a carrier of water humidity. During welding, the coating develops protective gas and gas is made of CO, CO2 and H2. The arc is unstable in H2, so it is necessary to increase voltage to obtain stable arc during welding.
People who use cellulosic electrodes in my country buy only Fronius TP 1500, and to my knowledge, no one competitor could offer 150A SMAW invertor with similar features with cellulosic electrodes.
TP 1500 has OCV = 92 V, and someone mentioned it has maybe higher working voltage than classic V=20+0.04A.
As far as I know, it is not possible to set Arc force at TP 1500, so I guess it is already programed to be on digging side.
I may only guess that Fronius TP 1500 (as small invertor of 150A) is No. 1 in welding with cellulosic electrodes because combining high OCV, higher working voltage and strong arc force unlike the competitors who produce small SMAW invertors to have enough "breath" just for basic electrodes.
I would be glad if someone could expertly explain what it is all need in SMAW invertors to weld with cellulosic electrodes.

 

[PTvor]

.
As far as I know, it is not possible to set Arc force at TP 1500, so I guess it is already programed to be on digging side.
I may only guess that Fronius TP 1500 (as small invertor of 150A) is No. 1 in welding with cellulosic electrodes because combining high OCV, higher working voltage and strong arc force unlike the competitors who produce small SMAW invertors to have enough "breath" just for basic electrodes.
I would be glad if someone could expertly explain what it is all need in SMAW invertors to weld with cellulosic electrodes.

If you look at the DECA inverter welders,

http://www.decaweld.com/default.asp?idA=34&idC=20&cmd=searchProd

they class them as Entry Level, Light Duty, Professional and Industrial. The only ones sold as capable of using cellulosics are the Industrial range and they have a highish OCV and adjustable arc force, so I'd suppose that it's as you say and to do with arc force. Adjustable arc force isn't a feature you find on cheap inverters.

If it's pre-set arc force, it will be a compromise, so it will be set for rutiles and basics or cellulosics.

This is far from an expert explanation. It doesn't account for AC machines with a high OCV range for instance.