Troubleshooting Values For Circuit Diagram (Use With Section 9-2) - Miller Trailblazer 302 Diesel Technical Manual

9-3. Troubleshooting Values For Circuit Diagram (Use With Section 9-2)

±
a) Tolerance − 10% unless specified
° °
b) Condition − 70 F (21 C); cold machine (no warm-up); Electrode Hot-Stick mode; no load; weld/power rpm unless
noted
c) Reference − single arrow: reference to circuit common (lead 42);
double arrow: reference to points indicated
d) Wiring Diagram − see Section 11
V1 CC/DC OCV: Stick mode: +46.5 volts dc (idle rpm), +45 volts dc (weld/power rpm); TIG mode: +10 volts dc (idle rpm), +10
volts dc (weld/power rpm)
V2 CC/AC OCV: Stick mode: 45 volts ac (idle rpm), 57 volts ac (weld/power rpm); TIG mode: 0 volts ac (not active)
V3 CV/DC OCV w/R1 at min: OCV: +13 volts dc (idle rpm), +13 volts dc (weld/power rpm)
V4 CV/DC OCV w/R1 at max: +35 volts dc (idle rpm), +35 volts dc (weld/power rpm)
V5 Exciter Winding: 18 volts ac (idle rpm), 29 volts ac (weld/power rpm)
V6 Weld Exciter Winding: 115 volts ac (idle rpm), 186 volts ac (weld/power rpm)
V7 24 V AC Winding: 18 volts ac (idle rpm), 24 volts ac (weld/power rpm)
V8, V9 Aux. Winding: 79 volts ac (idle rpm), 130 volts ac (weld/power rpm)
V10 Battery Input: +14 volts dc at all speeds and when engine is off and Engine Control switch S2 is on
V11 Circuit Board Power: +15 volts dc (idle rpm), +15 volts dc (weld/power rpm) Reference Lead No. 119 to Gnd
V12 Circuit Board Power: −15 volts dc (idle rpm), −15 volts dc (weld/power rpm) Reference Lead No. 119 to Gnd
V13 Engine Speed Control: 0.5 volts dc (idle rpm), 14 volts dc (weld/power rpm)
V14, V15, V16 Weld Windings: Stick mode: 35.5 volts ac (idle rpm), 35.5 volts ac (weld/power rpm): MIG mode w/R1 at max: 27 volts ac
(idle rpm), 27 volts ac (weld/power rpm); TIG mode: 8.6 volts ac (idle rpm), 9.8 volts ac (weld/power rpm)
V17 Exciter Rotor: +17.5 volts dc (idle rpm), +29.5 volts dc (weld/power rpm)
V18 Weld Rotor: Stick mode: +45 volts dc (idle rpm), +18−29 volts dc (weld/power rpm); MIG mode w/R1 at max: +32.2 volts
dc (idle rpm), +17.4 volts dc (weld/power rpm); TIG mode: +8.8 volts dc (idle rpm), +4.6 volts dc (weld/power rpm)
V19 Current Transformer: 0 volts ac (no load), 2.5 volts ac with 100 watt generator power load
V20 LEM Power: +15 volts dc (idle rpm), +15 volts dc (weld/power rpm) Reference Lead No. 144 = Gnd
V21 LEM Power: −15 volts dc (idle rpm), −15 volts dc (weld/power rpm) Reference Lead No. 144 = Gnd
V22 Current Feedback: 1 volt dc per 100 amps dc weld load (polarity dependent); 1 volt ac per 100 amps ac weld output
V23 Weld Voltage Feedback: Same as voltage across weld output terminals
V24 Throttle Solenoid Hold Coil: +14 volts dc (idle rpm), 0 volts dc (weld/power rpm)
V25 Throttle Solenoid Pull Coil: battery voltage for less than one second when TS1 is initially energized to bring engine to idle.
V26 Fuel Solenoid Hold Coil: +14 volts dc (idle rpm), 14 volts dc (weld/power rpm)
V27 Fuel Solenoid Pull Coil: battery voltage when starter is engaged
V28 Alternator Output: approximately +14 volts dc at all speeds
V29 Generator Shutoff Signal (originates on PC2): 0 volts dc during normal operation, +15 volts dc during a fault condition
V30 Zero Cross Signal (originates on PC1): +7.4 volts dc (2450 rpm), +7.75 volts dc (3750 rpm)
V31 Battery voltage supplied to Control Board PC2 when Engine Control switch S2 is on (engine does not have to be running).
Supplies 5 volt regulator on PC2.
V32 Fuel Level Sender: +0.6 volts dc when tank is full, approximately +5 volts dc when tank is empty
V33 Weld Capacitor: +140 volts dc (idle rpm), +245 volts dc (weld/power rpm)
V34 Exciter Capacitor: +17 volts dc (idle rpm), +30 volts dc (weld/power rpm)
TM-217 454 Page 40
Test Equipment Needed:
Voltage Readings
Trailblazer 302 D