Table 11 Ð Benshaw, Inc. Solid-State Starter Troubleshooting Guide

PROBLEM

 

PROBABLE CAUSES

 

AREA OF CORRECTION

AK board phase correct not

1.

L1 and L3 switch phases

1.

Switch incoming phases L1 and L3 at top of CD1 or CB1.

on.

 

reversed.

 

 

 

2.

Missing phase voltage.

2.

Check for missing phase voltage.

 

3.

Improper line voltage.

3.

Verify proper line voltage applied against synchronizing transformer

 

 

 

 

voltage.

AK board relay not on.

Ribbon cable not properly

Check ribbon cable for proper seating. Replace board if necessary.

 

seated.

 

 

AK board power

1.

Improper line voltage.

1.

Make sure proper line voltage is present at primary synchronizing

+15 vdc not on.

 

 

 

transformer.

 

2.

Transformer malfunction.

2.

Check synchronizing transformer secondary voltage as follows: On

 

 

 

 

the BC board, measure from TB11-1 to TB11-2 and TB11-1 to

 

 

 

 

TB11-3. Both readings should be within 30 to 36 vac. On the BC

 

 

 

 

board, measure from TB11-1 to TB11-4 and TB11-2 to TB11-4. Both

 

 

 

 

readings should be within 18 to 24 vac. Replace synchronizing

 

 

 

 

transformer if voltages are not within the speci®ed tolerances.

1L boards LEDs not on.

1.

A short exists between line

1.

Remove power and check resistance with ohmmeter.

 

 

and load terminals.

 

Locate and remove stray wire strands if required.

 

2.

An SCR is shorted in the

2.

Remove power. Use ohmmeter to measure the resistance or each

 

 

phase assembly.

 

SCR phase assembly from anode to cathode. The reading should

 

 

 

 

be 50,000 ohm or greater. If not, replace phase assembly.

BC board over-temperature

1.

Temperature switch not

1.

Disconnect power and check for continuity between TB11-10 and

LED (L3) on prior to run

 

functioning properly.

 

TB11-11. If no continuity exists, the overtemperature switch is not

command.

 

 

 

functioning properly. Replace defective switch if necessary.

 

2.

BC board not functioning

2.

Make sure BC board is functioning properly. Replace board if

 

 

properly.

 

necessary.

BC board LEDs on prior to run

BC board not functioning

Board not functioning properly. Replace board, if necessary.

command.

properly.

 

 

BC board LEDs not on after

1.

Phase assembly malfunction.

1. Remove power and check SCRs. Ohmmeter reading of each SCR

run command but before

 

 

 

gate to cathode resistance at terminals is 8 to 20 ohm. If not,

starter reaches full voltage.

 

 

 

replace the phase assembly.

 

2.

BC board not functioning

2.

Replace board, if necessary.

 

 

properly.

 

 

1L board LEDs remain on after

Imbalance between phases

Check for loose SCR gate lead or open SCR gate. Replace phase

starter reaches full voltage.

exists in motor terminal voltages.

assembly, if necessary.

BC board run LED (L5) not lit.

BC board not functioning

Measure 24 vdc at TB11-8 to TB11-4. If voltage is present, replace

 

properly.

board. If not present, replace relay 1CR.

AK board power applied, run

AK board not functioning

Replace board.

command given, starter at full

properly.

 

 

voltage, but aux LED not lit.

 

 

 

 

1L boards LEDs lit.

Motor terminal voltage phase

Check motor terminal voltages for imbalance between phases. If an

 

imbalance exists.

imbalance exists, check for loose SCR gate or open SCR gate.

 

 

 

Replace phase assembly, if necessary.

BC board LED L4 and L5

BC board not functioning

Replace board.

not lit.

properly.

 

 

BC board LED L3 lit.

1.

FU5 and FU6 fuses not

1.

Check fuses FU5 and FU6. Replace if necessary.

 

 

functioning properly.

 

 

 

2.

Phase assembly not

2.

Verify that bypass is pulling in by measuring the voltage drop

 

 

functioning properly.

 

across the contacts. The reading should be 50 mV or less.

 

 

 

 

Replace phase assembly, if necessary.

 

3.

Fan not functioning properly.

3.

Verify fan operation on each phase for 200 amp units. Replace

 

 

 

 

fan, if necessary.

BC board L2 lit.

SCR phases not functioning

Measure resistance from anode to cathode for each SCR phase

 

properly.

assembly. Replace shorted phase, if necessary.

BC board L1 lit.

Motor lead grounded.

Megger motor to test for motor lead going to ground.

Start command given.

Motor does not begin rotation.

Turn `Starting Torque' potentiometer RV2 clockwise until motor

 

 

 

rotation begins.

Motor does not reach full

Ramp up setting is not correct.

Turn `Ramp' potentiometer RV1 counterclockwise. Restart motor

speed within 25 seconds.

 

 

and verify that motor reaches full speed within 25 seconds.

115 vac missing from LL1

1.

CB2 is not on.

1.

Verify CB2 is on.

and LL2.

2.

Fuse no. 4 (FU4) blown.

2.

Check FU4 for continuity. Replace, if necessary.

 

SMM not responding.

1.

CB4 is not on.

1.

Verify CB4 is on.

 

2.

Potentiometer RV1 needs

2.

Adjust potentiometer RV1 for 24 vac at SMM terminals J3-23 and

 

 

adjustment.

 

J3-24.

 

 

 

LEGEND

 

 

AK

Ð

Vendor Board Designation

L1, L3

Ð

Terminal Board

BC

Ð

Vendor Board Designation

LL1, LL2

Ð

Control Power Terminals

CB

Ð Circuit Breaker

RV1

Ð Line Voltage Signal Calibration

CD

Ð Disconnect Switch

SCR

Ð Silicon Control Recti®er

CR

Ð Control Relay

SMM

Ð Starter Management Module

FU

Ð Fuse

TB

Ð Terminal Board

LED Ð Light-Emitting Diode

84

Page 84
Image 84
Carrier 19XL Benshaw, Inc. Solid-State Starter Troubleshooting Guide, Problem Probable Causes Area of Correction, RV1, Scr

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