VANNER
Incorporated
OWNER’S MANUAL
Vanner High Voltage DC-
DC Converter OWNER’S MANUAL
19
Testing an HBA for an Isolation Fault
In the event the vehicle is experiencing an isolation fault, the HBA should be eliminated as the cause of
the fault prior to replacing any hybrid drive components. The isolation resistance of an HBA can be
tested using an Amprobe AMB-45 Megohmmeter, commonly referred to as a "megger".
1.
Before beginning, reference Allison Transmission's "Electrical Disconnect Verification Procedure" for
the H 40/50 EP product family. It contains important steps that are not covered in these instructions.
2.
High Voltage Personal Protective Equipment (PPE) must be worn for this procedure.
3.
Assure that the vehicle ignition switch is in the OFF position.
4.
Assure that the vehicle master battery disconnect switch is in the OFF position. Use lockout devices
to assure the switch cannot be moved to the ON position until the test procedure is complete.
5.
Disconnect the high voltage positive and negative cables from the HBA input studs.
6.
Insulate the ring terminals.
7.
Do not disconnect the 24V positive and negative cables, 14 pin Deutsch connector, and chassis GND
from the HBA.
Note:
If bench testing, connect HBA 24V negative to HBA chassis.
8.
Set the AMB-45 to the 250V scale.
9.
Connect AMB-45 negative to HBA chassis.
10.
Connect AMB-45 positive to HBA high voltage positive stud. Measure and record resistance.
11.
Connect AMB-45 positive to HBA high voltage negative stud. Measure and record resistance.
12.
See table below for proper resistance readings.
13.
If either resistance reading is significantly lower than specified, the HBA may be defective and should
be returned to Vanner for repair.
HBA Serial Number
Positive to Chassis Negative to Chassis Actual Measurement
Prior to 13246-250093
810kΩ ±10%
Pos to Chassis:
Neg to Chassis:
After 13246-250093
2.8MΩ ±10%
Pos to Chassis:
Neg to Chassis:
Vanner Repair Service
Vanner offers a quick turnaround factory repair service. Send the unit to the address on last page
with a note instructing us to repair it. Include your name, phone number, shipping address (not a
P.O. Box Number), and your purchase order number.
WARNING!
The Vanner HBA uses potentially lethal voltages for operation.
DO NOT
attempt to test
the HBA unless you have been trained to work with the Allison H 40/50 EP system.
