Instruction manual

ACU-1000 Operations Manual
Interoperability Now 2-9
2.7.3 External Chargers
If an external charger is required, it is recommended that a 2 step constant-voltage constant-
current type charger be used as it is the fastest, and most efficient, and does not overcharge the
battery. Many chargers allow adjustment to optimize for cyclic use or float use. It is not
recommended that series or parallel batteries be used as there are significant charging problems
that can occur. If more standby time is required, simply getting a larger battery is the preferred
solution.
2.7.4 Charge Switch
The Charge Switch, SW3, should be set to CHARGE only if the Raytheon battery back-up kit
is being used. (See Table 1-3 Optional Equipment - Not Supplied). The charge current drain
must not exceed 1 ampere.
2.7.5 Fuse Information
There are 3 fuses used in the ACU-1000 chassis. They are as follows:
F1 Common, unfiltered DC bus voltage
F2 AC input fuse
F3 DC input fuse
F1 fuses the unfiltered low level DC bus voltage from the PSM-1A that powers the +5V DC
switching supplies on each of the other chassis modules. F1 prevents damage to the PSM-1A if
a short circuit or other unusual load is applied to this bus.
F1 can only be replaced if the PSM-1A is removed from the chassis. Be sure to remove all AC
& DC input cabling prior to removing or servicing the PSM-1A.
See Figure 2-4 below for a fuse troubleshooting chart.