WCL488 Series Water Cooled Electronic Loads
Operation & Programming Manual
TDI-Dynaload Division
Page 112
402828, Rev. B1
Appendix G — Troubleshooting Guide
The information immediately below includes a brief description of fault conditions and
indicators. The balance of this appendix addresses symptoms, possible causes, and explanations
and corrective actions.
Troubleshooting Fault Conditions and Indicators
“SYS” (System)
Fault LED
Lights red for a major fault. A major fault means the load will not
draw current and will not connect to the source under test. Major
faults include “ OV” , “ UV” , “ OT” and AC fail.
Lights yellow for a minor fault. A minor fault will allow the unit to
continue operating but may not be at the programmed setpoint due to
a limit protection circuit. Minor faults include “ I LIM” , “ P LIM” ,
“ SAT” , and “ MOD” fault.
“OV”
(Overvoltage)
Fault LED
Lights red when the loads input voltage exceeds the voltage limit
setpoint menu item number 2. The DC load relay will not close until
the input voltage is less than the setpoint.
“UV”
(Undervoltage)
Fault LED
Lights red when the input voltage is between zero and 0.6 volts and
the “ UV” switch on the rear panel is on. The DC load relay will not
close in a “ UV” condition.
“TEMP”
(Temperature)
Fault LED
Lights red when one or more internal power modules overheat. This
will disconnect the load and reset once allowed to cool.
“I LIM” (Current
Limit) Fault LED
Lights yellow when the loads current reaches the current limit
setpoint menu item number 1. This is a “ minor” fault.
“P LIM” (Power
Limit) Fault LED
Lights yellow when the loads power reaches the power limit setpoint
menu item number 3. This is a “ minor” fault.
“SAT”
(Saturation) LED
Lights yellow when there is insufficient source voltage to support
the programmed current.*
May also indicate one or more component failures in the loads
power section. This is a “ minor” fault.
“MOD” (Module)
Fault LED
This LED is inactive in the WCL488 and should never light.
* Compliance Voltage: The minimum input voltage at which the load can sink its maximum
rated current. Loads can operate below the minimum compliance voltage but will not be able
to achieve full rated current.