MTS Hydraulic Power Unit Model 506-92 - Manual (Page 28)

3-16 Service
3 . 3 . 1 Abnormal HPU Shutdown
Motor
overload Sudden shutdown of the HPU may be due to circuit protection elements
in the pump motor starter assembly. If the supercharge motor overloads,
the relay opens and de-energizes the motor starter coils to shut down the
HPU. If either pump 1 or pump 2 motor overloads, the associated pump
shuts down.
Reset procedure If a motor overloads, follow this procedure to reset it.
1. Turn off ac power at the HPU disconnect switch.
WARNING !
High voltage is present in the starter assembly if power is not removed.
Failure to remove power before opening the HPU starter box door may
cause death or injury.
Remove electrical power at the power disconnect switch.
2. Open the starter box door and locate the appropriate motor overload
relay (see Figure 3-4).
3. Press the reset button located on the relay to enable operation.
N O T E The overload relay element may be equipped with a
switch to provide manual or automatic reset. This switch
should always be set to the manual position.
3 . 3 . 2 Fuse Replacement
Table 3-2 lists the fuse values and part numbers of the fuses located in the
506.82 and 506.92 standard 460 Vac, three-phase starter assemblies. Figure
3-4 shows the location of the fuses.
Table 3-2. Starter Assembly Fuse Values
Fuses 506.82 HPU 506.92 HPU
Type MTS PN Type MTS PN
FU 1 through FU 3 45A slo-blo 100725-15 70A slo-blo 100725-37
FU 4 and FU 5 3A slo-blo 111457-06 3A slo-blo 111457-06
FU 6 6A slo-blo 100524-27 6A slo-blo 100524-27
FU 7 4A slo-blo 100524-04 4A slo-blo 100524-04
FU 8 through FU 13 250A slo-blo 100725-52 350A slo-blo 100725-61