Carrier PC211 Start-Up, Operation And Maintenance Instructions Manual page 306

Table 12 — Benshaw, Inc. Solid-State Starter Troubleshooting Guide (Continued)
Problem
AK board power
applied, run command
given, starter at full
voltage, but aux LED
not lit.
1L boards LEDs lit.
BC board LED L4 and
L5 not lit.
BC board LED L3 lit.
BC board L2 lit.
BC board L1 lit.
Start command given.
Motor does not reach
full speed within 25
seconds.
115 vac missing from
LL1 and LL2.
SMM not responding.
Legend
LED — Light-Emitting Diode
SCR — Silicon Control Rectifier
SMM — Starter Management Module
Probable Causes
AK board not functioning
properly.
Motor terminal voltage
phase imbalance exists.
BC board not functioning
properly.
1.
FU5 and FU6 fuses not
functioning properly.
2.
Phase assembly not
functioning properly.
3.
Fan not functioning
properly.
SCR phases not function-
ing properly.
Motor lead grounded.
Motor does not begin rota-
tion.
Ramp up setting is not cor-
rect.
1.
CB2 is not on.
2. Fuse no. 4 (FU4) blown.
1.
CB4 is not on.
2. Potentiometer RV1
needs adjustment.
Area of Correction
Replace board.
Check motor terminal voltages for imbalance between
phases. If an imbalance exists, check for loose SCR gate
or open SCR gate. Replace phase assembly, if necessary.
Replace board.
1.
Check fuses FU5 and FU6. Replace if necessary.
2.
Verify that bypass is pulling in by measuring the voltage
drop across the contacts. The reading should be 50 mV
or less. Replace phase assembly, if necessary.
3.
Verify fan operation on each phase for 200 amp units.
Replace fan, if necessary.
Measure resistance from anode to cathode for each SCR
phase assembly. Replace shorted phase, if necessary.
Megger motor to test for motor lead going to ground.
Turn 'Starting Torque' potentiometer RV2 clockwise until
motor rotation begins.
Turn 'Ramp' potentiometer RV1 counterclockwise. Restart
motor and verify that motor reaches full speed within 25
seconds.
1.
Verify CB2 is on.
2. Check FU4 for continuity. Replace, if necessary.
1.
Verify CB4 is on.
2. Adjust potentiometer RV1 for 24 vac at SMM terminals
J3-23 and J3-24.