Yaskawa GPD 506/P5 Section One - Manual (Page 29)

PP.P5G5.01.Troubleshoot
Page 29
Rev. 06/11/2003
DC Bus Fuse
The DC Bus fuse is located in the positive portion of the DC bus in 460v and 600v units, 3.7kW
and smaller ,(5.5 and smaller for 230v units), and in the negative portion in all other sizes. The
DC bus fuse is used to protect the main circuit components if the output transistors short. If the
DC bus fuse is open, at least one of the output transistors has failed. When a transistor fails,
there is a short between the positive and negative portions of the DC bus. Again, the DC bus fuse
does not protect the transistors, but protects the rest of the main circuit from the high current
present during a short. Never replace the DC bus
fuse without first checking all of the output transistors.
Caution: If the DC bus fuse is replaced without replacing the shorted output transistor, non-
warranty damage will occur.
T3
T2
T1
1FU
L1
L2
L3
(+)
(-)
Main Circuit Diagram
Typical for 3.7kW models and below. All other models
have fuse in negative portion of the DC bus.