MTS Series 505 SilentFlo Hydraulic Power Unit Model 505-180 - Manual (Page 94)

Model 505.60 - 505.180 SilentFlo™ HPU 94
Replacing the Return-line Filter
Maintenance
5. Detach the cable and remove the existing low level/temperature fixture.
Install the replacement fixture and attach the cable.
Note Ensure that the new fixture has the same length as the old one.
Raise the low level assembly high enough to cause the operator interface to
flash Low Level.
6. Lower the fixture back into the reservoir to match the distance between the
head assembly of the fixture and the top of the reservoir.
7. Press the Reset button on the user interface to clear the interlock and change
the HPU Run Status back to NORMAL.
How to check the over
temperature switch
To check the fixture:
1. Turn on power to the hydraulic power unit.
2. Turn off the water flow to the HPU (this prevents the heat exchanger from
working).
3. Monitor the temperature on the Main Display on the user interface. When
the hydraulic fluid temperature exceeds 55°C (131°F), HPU Run Status
should flash between Faulted and Over Temp. If Over Temp does not
display, replace the low level assembly.
4. Turn on the water flow to the HPU.
5. Press the Reset button to clear the interlock and turn the indicator off.
Replacing the Return-line Filter
The standard fine filter for the Model 505.60/.90 and Model 505.120/.180 HPUs
is a return-line filter. The HPU will have one of two filter housing designs. The
filter housing design is distinguished by the method used to secure the cover.
Either a clamp holds the cover to the head assembly or cap screws secure filter
cap. There is also an optional high pressure filter that can exist on any particular
unit.
Clamp-Style Housing Filter Replacement
The return-line filter element of the HPU should be replaced for the following
reasons:
• When the dirty-filter detector trips
• Whenever the hydraulic fluid is changed
• The filter manufacturer’s recommended maximum interval
(1000 hours or 6 months)