Quantech QTC4 STYLE A Series Installation Operation & Maintenance page 155

FORM QTC4-NM1
ISSUE DATE: 4/2/2018
TABLE 25 - TROUBLESHOOTING GUIDE (CONT'D)
PROBLEM
SYSTEM STATUS:
MOTOR CURRENT
LIMITING
VSD FAULT:
HIGH BASEPLATE
TEMPERATURE
VSD FAULT:
LOW DC BUS VOLTAGE
NOTE: Always remove power to the chiller and assure the DC Bus voltage has bled off.
QUANTECH
POSSIBLE CAUSE
A high motor current anticipatory control
has activated current limiting.
Coolant level low.
Glycol Pump is defective.
VSD Board is defective
IBGT Module is defective.
SCR / Diode Module is defective.
SCR Trigger Board is defective.
SECTION 9 - MAINTENANCE
ACTION
Ambient temperature is high, normal
response from controller
Remote or panel limiting is in effect,
Normal response.
Excess charge in system, adjust charge.
Condenser coils dirty, Clean condenser.
Fans NOT operating. Check fans.
Add coolant.
Replace Glycol Pump.
Replace VSD Logic Board.
Check defective IGBT Module.
Check SCR / Diode Module.
Check SCR Trigger Board.
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