 | |
| Illustration 1 | g01277295 |
Controls Cabinet Back Panel (29) Customer Contacts Interface Board #2 (Optional) (30) DC Bus Pre-charge Circuit Resistors (31) T1 - T4 Transformers (32) Power Supply Board (PWS) (33) Customer Contacts Interface Board #1 (34) Power Supply Board (PWS) (35) Thermistor (36) Fuse F69 (37) Fuses F88-F90, F70-F72 (38) Zig-Zag Transformer (39) K7 Pre-charge Contactor (40) K6 Pre-charge Contactor | |
The DC Bus Pre-charge Circuit Resistors are a part of the DC bus pre-charge circuit and are wired in series. The pre-charge circuit allows the system to charge the DC bus prior to operating in line-interactive mode. The resistors limit the in-rush current during pre-charge.
 | |
| Illustration 2 | g01277862 |
DC Bus Pre-charge Circuit Resistor Array | |
There are 12 resistors. Each resistor is a hollow tube with insulating spacers on both ends. The resistors are connected to the cabinet by a metal rod that extends through the middle of the tube and connects with two nuts to the metal bracket attached to the rear panel of the cabinet.