ESAB Heliarc 252 & 352 Low Current Kit Installation guide

Brand: ESAB

Model: Heliarc 252 & 352 Low Current Kit

Type: Installation guide

Required Items

1 ea.--16 ohm 300W Resistor PN-17300016

2 ea.--Resistor Brackets PN-99512558

2 ea.--1/4” Mounting Screws PN-6125900

1 ea.--Bridge Diode PN-13730469

1 ea.--.02 mf Capacitor PN-674216

1 ea.--1” Mounting Screws PN-61325886

2 ea.--Flat Washers PN-64304880

1 ea.--Hex Nut PN-63300886

Change R44 Main PCB 60 hz. (38055) to 20 ohm.

16 ga. wire, connectors and tie wraps

Installation Procedure

1. Be sure

ALL power is disconnected from the

power source before removing any sheet

metal.

2. Remove the top and left side power source

sheet metal.

3. Assemble the circuit using the above sche-

matic as a reference. Be careful to measure

the correct wire length based on the recom-

mended placement of components.

4. Mount 16 ohm (300 W) resistor on opposite

side of lifting bail using the “L” brackets and

1/4” mounting screws as shown.

5. Route the wires of bridge diode along the

inside of the “A” frame and mount the bridge

diode to the front side of the “A” frame post

using the 1” long screw, washer, and hex nut

as shown.

Installation Instructions for

Heliarc 252 & 352

Low Current Kit

0558007408 03 / 2007

6. Attach the lugged end of the wire (resistor

side of the circuit) to the cathode side of

the SCR bridge as shown. Locate hex nut

and stud holding the copper bus to the

heat sink and place the wire ring lug under

the hex nut on the stud and secure.

7. Attach the lugged end of the wire (diode

side of the circuit) to the anode side of the

SCR bridge as shown. Locate hex nut and

stud above snubber PC board and place

the ring lug on the stud under the Hex nut

and secure.

8. Remove the screws in the upper corners

of the power source front control panel.

Pull the panel forward to expose the main

control board. Replace the R44 resistor

with a 20k ohm resistor.

9. Tie wrap and secure routed wires to exist-

ing wire harnesses or frame members.

10. Replace and secure all sheet metal sides

and hardware.

Notes on Heliarc 252 & 352 Low Current Operation

This low current circuit enhances the arc stability when welding at currents down to approx. 4 amps

for DC and 8 amps with AC. The circuit minimizes arc wander around the tungsten point that can

occur with low current operation. This modication also increases the usable arc lengths during

welding. The high frequency can be set to the “start only” or “continuous” position depending on

application and customer preference. Be sure to set the arc force to minimum and the balance

control Max. penetration for best AC performance and Max. Cleaning for best DC performance.

Arc starting at minimum currents (4 amps) requires a very short tungsten to work distance (<.040”).

Use the recommended tungsten size for the desired current for best arc starting characteristics. At

4 amps a .040” tungsten is recommended but good arc starts can be achieved using a 3/32” tung-

sten. Arc starting consistency with larger diameter tungsten is dependent on electrode pointing

techniques, grounding and base material surface condition.

When welding below a 6 amps preset current, use the HF “continuous” position to minimize arc

outages and allow more tolerance to changes in tungsten to work distance.

0558007408 03 / 2007

ESAB Heliarc 252 & 352 Low Current Kit Installation guide

ESAB Heliarc 252 & 352 Low Current Kit Installation guide

ESAB Heliarc 252 & 352 Low Current Kit Installation guide

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