Service difficulty report · Inverter · Dhav DHC8201

Difficulty date
November 29, 2002
Submitted
January 6, 2003
Operation
General aviation
Make and model
Dhav DHC8201
Engine
Pwa PW123D
Propeller
Hamstd 14SF7
System (JASC)
2422 · AC Inverter
Part
Inverter
Part number
DH1030246
Condition
Failed
Location
Electrical
Stage of operation
CL
How discovered
O
Nature of condition
B, G, H
Precautionary procedure
O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

(CAN) JUST AFTER THE A/C BECAME AIRBORNE, CREW NOTED A SMOKE ODOR IN THE COCKPIT. PRIMARY INVERTER, DC CIRCUIT BREAKER OPENED. THE AUX AND SECONDARY INVERTER DC CIRCUIT BREAKERS OPENED ALMOST IMMEDIATELY THEREAFTER. BOTH 400HZ BUSSES, AND 26 VAC BUSSES BECAME UNPOWERED, WITH THE ASSOCIATED LOSS OF SERVICES. THE PRIMARY INVERTOR FAILED, THE AUX INVERTOR WAS SELECTED TO THE LT BUSS AT THE TIME. WHEN THE PRIMARY INVERTOR FAILED, THE SHORT CIRCUIT INTERNAL TO THE INVERTOR, DRAGGED DOWN THE AUX INVERTOR, AND IT ALSO WENT OFF LINE. THE REMAINING SECONDARY INVERTOR WAS UNABLE TO HANDLE THE ELECTRICAL LOAD AND IT ALSO DROPPED OFF LINE. THE BUSS TIE CIRCUIT BREAKER, (3.5 AMP, CB 14) DID NOT OPEN. INVERTOR REPLACED