MAINTENANCE
Gentherm Global Power Technologi
es
Page 61
4.
Run a jumper wire from terminal 2 to the TEG chassis and watch the voltage reading.
Remove the jumper wire. Any fluctuation in voltage may indicate an internal short
within the power unit.
5.
Run a jumper wire from terminal 1 to the TEG chassis and watch the voltage reading.
Remove the jumper wire. Any fluctuation in voltage may indicate an internal short
within the power unit.
6.
If an internal short is confirmed, with no other equipment connected, the power unit
is damaged and will need replacing. If not and the TEG appears to be fully functional
check the customer load is functioning correctly and is grounded properly.
9.6.2
Check Internal Resistance
Follow these steps to check the power unit’s internal resistance:
1.
Start the TEG.
2.
Disconnect the customer load from terminals 7(+) and 8(-) of TB-1.
3.
Connect a voltmeter between terminals 5 (+) and 6 (-).
4.
Pause for sufficient time to get a stable measurement of V
set
between terminals 5 and
6. 15 minutes is often sufficient if the TEG was already warm. 1 hour is often sufficient
if the TEG was just started from cold.
5.
Record V
set
.
6.
While observing the voltmeter display remove the Connection from Terminal 1 of TB1,
creating an open circuit condition, and note the momentary voltage. On a digital multi-
meter this will be the first number displayed after removing the connection, within 2
seconds of removing the connection. Record the number as the momentary open
circuit voltage (Voc). If this was not recorded quickly enough replace the connection
and repeat steps 4 to 6 above.
Figure 28 - Momentary Open Circuit Diagram
