Trouble

Remedy

 

 

 

 

 

Check Control relay CR2 contacts 4 and 7 for proper operation. Replace CR2 if necessary.

 

 

 

Check coil voltage and connections of gas valve GS1. Check continuity of coils. Replace GS1 if nec-

 

essary.

 

 

No power output at 115 volts ac recep-

Check circuit breaker CB1, and reset if open (see Section 7-2).

tacle RC1; weld output available.

 

 

 

Fan motor FM does not run; weld out-

Check and clear fan blade obstruction.

put available. Effective with Serial No.

 

KG164875, unit is equipped with Fan-

 

On-Demand, which only runs when

 

cooling is required.

 

 

 

 

Check coil voltage and connections of fan motor FM, and replace if necessary.

 

 

Line fuse opens immediately when

Check diode D1, and replace if necessary.

solid-state contactor SR1 turns on in

 

DC mode only.

 

 

 

 

Check SCRs in main rectifier SR1, and replace if necessary. If any SCRs are replaced, Check capac-

 

itors C7 through C10 for a short or open, and check for proper connections. Replace C7 through C10

 

if necessary.

 

 

No control of weld output.

Check position of Amperage Control switch S5 (see Section 4-7).

 

 

 

Check resistance and connections of Amperage Adjustment control R1; R1 is 1000 ohms ± 10%.

 

Replace R1 if necessary.

 

 

 

Check, repair or replace remote control device.

 

 

 

Effective with Serial No. KB110695, check resistance and connections of HD1; HD1 is 1600 ohms

 

± 10% between pins 1 and 3 of plug PLG3. Check input and output voltages. Replace HD1 if

 

necessary.

 

 

 

Check control board PC1 and connections, and replace if necessary.

 

 

Tungsten electrode oxidizing and not

Check position of Postflow Time control R12 (see Section 4-10).

remaining bright after conclusion of

 

weld.

 

 

 

 

Check and tighten all gas fittings if necessary.

 

 

 

Increase gas flow setting.

 

 

 

Shield weld zone from drafts.

 

 

 

Properly prepare tungsten.

 

 

 

Place High Frequency switch S2 in Start or Continuous position.

 

 

Wandering arc - poor control of direc-

Use proper size tungsten for welding application.

tion of arc.

 

 

 

 

Properly prepare tungsten.

 

 

Controls connected to Remote 14

Check, repair or replace remote control device.

receptacle RC1 do not work properly.

 

 

 

 

Check Amperage Control switch S5 position (see Section 4-7). Check and replace S5 if necessary.

 

 

 

Check Output (Contactor) switch S3 position (see Section 4-8). Check and replace S3 if necessary.

 

 

 

Check position of jumper links 1 and 2 on terminal strip 1T according to Section 6-2.

 

 

 

Check coil voltage and connections of control relay CR2. Check continuity of coil and condition of

 

contacts. Replace CR2 if necessary.

 

 

 

Prior to Serial No. KF959379, check choke RFC1 connections. Check continuity of RFC1. Replace if

 

necessary. Effective with Serial No. KF959379 check remote 14 filter board PC2 (see Section 6-6).

 

Replace PC2 if necessary.

 

 

 

Check control board PC1 and connections, and replace if necessary.

 

 

Ammeter A1 not displaying correct

Calibrate ammeter as instructed in Section 6-8.

weld output amperage.

 

 

 

 

Check ammeter A1 voltage; +1 millivolts dc per 3 ampere of weld output. Replace A1 if necessary.

 

 

 

Check control board PC1 and connections, and replace if necessary.

 

 

 

Effective with Serial No. KB110695, check resistance and connections of hall device HD1; HD1 is

 

1600 ohms ± 10% between pins 1 and 3 of plug PLG3. Check input and output voltages. Replace HD1

 

if necessary.

 

 

Voltmeter V1 not displaying correct arc

Check connections for continuity to voltmeter V1. Replace V1 if necessary.

voltage.

 

 

 

Electronic equipment in welding area

HF interference problem. Check for proper installation, and correct problem (see Section 8).

not working properly.

 

 

 

Syncrowave 250

TM-353 Page 25

Page 29
Image 29
Miller Electric TM-353E manual Contacts. Replace CR2 if necessary