Tweco 81 with SL100SV - Manual (Page 91)

Manual 0-4641 5-27 SERVICE
5
C. Diode Module Board Tests
WARNING
Disconnect primary power at the source before taking any resistance checks.
1. Input Diode Test
a. Disconnect input AC power.
b. Check Input Diode for shorted input diode. With an ohmmeter set on the diode range make the following checks from
Main PC Board to Input Diode:
For 400-Volt, 415-Volt, 460-Volt, and 600-Volt Power Supplies: For 208/230-Volt Power Supplies:
Meter + Meter - Indication
E15 E1 Diode Drop
E1 E15 Open
E15 E2 Diode Drop
E2 E15 Open
E15 E3 Diode Drop
E3 E15 Open
E7 E1 Open
E1 E7 Diode Drop
E7 E2 Open
E2 E7 Diode Drop
E7 E3 Open
E3 E7 Diode Drop
E7 E15 Open
E15 E7 Diode Drop*
400V, 415V, 460V, and 600V
Input Diode Indications
* Indication can be twice
other indications.
Meter + Meter - Indication
E7 E1 Open
E1 E7 Diode Drop
E15 E1 Diode Drop
E1 E15 Open
E15 E7 Diode Drop*
E7 E15 Open
208/230V Input Diode Indications
* Indication can be twice
other indications.
c. The meter should indicate a diode drop in one direction and an open in the other direction for each check. Replace the
Input Diode Module Board if the readings do not match the chart.
d. If Input Diode Module Board is shorted, make the following checks with an ohmmeter at the Main Contactor (W1):
Meter (+) Meter (-) Indication
L1 T1 Open
L2 T2 Open
L3 T3 Open
If any test has resistance, then replace the Main Contactor.