[semi-lucid]

Hello

I ran across an ESAB PCM 150 for $750, and it seemed too cheap to pass up. I bought the machine from a legitimate dealer, so I don't think it is stolen or anything, but it seems odd to me that the machine is equipped with a PT 20AM machine torch, but there is no table.

The seller stated that "This unit was removed working from a local machine shop that went out of business." When I asked about the table, he said he never seen the table.

This power supply looks almost identical to the ESAB ESP 150, which I think is about a $7k power supply. (I'm not sure about this price.)

Was $750 a steal? This is a 150 amp, 90% duty cycle machine.



My question is about torches. I would like to have both a hand torch and a machine torch, and I think the PT 20 AM does no use air for the gas.

Any recommendations ?

[semi-lucid]

Does anyone have an opinion about this "Alpha 1" torch ? It's available in a hand model for about $600. (150 amp, 50% duty cycle) Its also available in a machine torch model.

http://www.weldmart.com/ALPHA%201%20...20PG%20MST.htm

[semi-lucid]

On ESAB's web site they have the PT 20 AMX listed as:

Up to 100 Amps, Air Cooled, 1-3/8" Diameter Torch Barrel, Single Gas Torch (shop air).

http://products.esabna.com/EN/home/p..._plasma_pt2021

Somewhere I got the idea that the PT 20 AM used oxygen for the plasma gas. But still it's only rated at 100 amps, while my power supply is 150 amps.

Can someone explain the difference between high frequecy start, and pilot arc start?

[jimcolt]

Your best bet is to call Esab's tech service line and get suggestions from them in regards to the best torch for your use. My info tells me that that system....which is a rather old design...was originally only used as a nitrogen plasma, carbon dioxide shield gas system. These gases work well on non ferrous (aluminum and stainless steel) but (by todays standards) produce very ugly cuts on steel. The original torch...I believe...was a PT121 or PT121M torch for that system.

I believe the system can be adapted to a variety of different torches...although some other equipment may be required to do that....the tech service group at Esab may be able to help.

High frequency start and pilot arc start are totally different terms.

High Frequency is a high voltage (AC) produced at a high frequency....this high voltage is used to ionize the plasma gas between the electrode and nozzle in a plasma torch to get the plasma process started.

A "Pilot Arc" is a non transferred DC arc that is formed between the electrode (negative) and the nozzle (positive) at the plasma torch.....it is forced out through the nozzle orifice by the plasma gas flow...and allows the plasma system to transfer the arc to the plate efficiently...even if the surface of the plate is underwater or dirty or painted.

There are some plasma torches that have only high frequency...they will not fire a robust arc in the air...and must be very close to the plate to allow the ionized gas to transfer the DC energy to the plate. Many of the low cost Asian import plasma's use this method to start the plasma arc...it is also known as a "scratch start".

There are many plasma torches that have both high frequency and a pilot arc....if these are hand plasma systems...they are usually older design systems. The high frequency arcs between the electrode and nozzle, ionizing the plasma gas and allowing the DC energy to form a robust arc that will melt through almost anything on the surface of the plate...the arc will fire in the air.

Most new hand held air plasma systems under 100 Amps have the ability to fire a pilot arc without the use of high frequency. these torches have a moving electrode (Hypertherm calls it "Blowback Start") that creates a short circuit spark that ionizes the gas, allowing the DC to create a robust pilot arc.

Hope that helps a little. Your PCM150 has both high frequency and pilot arc.

Jim Colt Hypertherm

[semi-lucid]

Jim

Thanks for the information.
I have a lot of experience with oxy/fuel and welding, (stick/mig/tig/resistance) but I've never owned a plasma cutter, and I'm on a learning curve, so sorry about my stupid questions.

"My info tells me that that system....which is a rather old design...was originally only used as a nitrogen plasma, carbon dioxide shield gas system."
"The original torch...I believe...was a PT121 or PT121M"

It appears that the design dates back to the L-Tec days. The L-Tec PCM 1500 became the ESAB PCM 150, and then the ESAB ESP 150.

The older model PCM 150's had the PT 121 as the standard torch, with an option to use a PT 17A or PT 20, using shop air.
These later two torches apparently required an adapter called PCC 11. I haven't figured out exactly what a PCC 11 is.

On the later model PCM 150's, the standard torches are the PT 20AM or the PT 25.
That makes me think the torch on my unit is original, and a proper torch for it.

"The patented PT-20AM is a 100 amp capacity, pilot-arc
mechanized torch The torch uses clean, dry air as the cut gas for
cutting carbon steel, aluminum, or stainless steel. DO NOT
use oxygen; a hazardous fire may result."

The ESP 150 uses a water cooled PT-26 torch, 70°, 90° or In-Line. The ESP model has a built in water cooling control.

Then there's the Deuce Pack:

"The DEUCE PACK 150 package includes two PCM-150
consoles, interface kit, torch, coolant circulator, spare parts
kit, regulator, gas hoses, work cable, water hose."

300 amps @ 90% duty cycle.
I would like to know what that interface kit and coolant circulator consists of. If I could find another power supply I could rock and roll.

If you want any more info, see page 2-29 of the catalog below.

http://www.twsco.com/Catalog/ESAB/Se...ection%202.pdf

I'm interested in bevel cutting in heavy plate, so I'm looking at the ESAB PT 600 torch. I found that Centricut makes a version of that torch. Is the Centricut C96 994 unit lower priced than the ESAB unit?

http://centricut.com/ProductBulletin...bly_C96993.pdf

I found one place on the net with prices on the ESAB PT 600, and I was surprised that the length of the leads makes a huge difference in price.

21 feet of leads costs $1000. Why is that?

[jimcolt]

It is a water cooled lead that is designed for up to 600 Amps, also carries gases (plasma and shield) as well as pilot arc current.

Jim

[semi-lucid]

At $47.60 per foot, I wish the would offer a 300 amp version. It didn't appear the Centricut part was offered with leads.