MTS Series 505G2 SilentFlo Hydraulic Power Unit Model 505G2-180 - Manual (Page 63)

Hyd fluid overtemperature
A hydraulic fluid overtemperature interlock is indicated on the Main screen by a flashing red Faulted indicator,
a blue Bypass indicator, a red Oil Temp indicator, and a blue Status indicator. The interlock is generated
when the temperature exceeds 55°C (131°F). The interlock will automatically shut down the HPU. The HPU
cannot return to normal operation until the fluid has cooled. Perform the following to correct an overtemperature
interlock:
1. Start cooling the hydraulic fluid by circulating hydraulic fluid through the heat exchanger (Overtemp Bypass
mode).
a) If necessary, press the Main button to select the Main screen.
b) Ensure that Module #1 Enabled is green.
c) Press the Bypass button. Pump module #1 will start and run to circulate the hydraulic fluid through
the heat exchanger. The red flashing Faulted indicator changes to yellow Overtemp Bypass and the
Bypass button changed to Stop.
2. If the there is no change in the Oil Temp reading after several minuets, determine if the hydraulic fluid is
receiving adequate cooling.
• The cooling water inlet temperature affects the efficiency of cooling the hydraulic fluid.
• Check the cooling water inlet-to-outlet pressure differential. It should be between 0.24–0.31 MPa (35–45
psi). If necessary, adjust the water pressure at its source.
3. After the displayed fluid temperature drops below 55°C (131°F), press the Stop button.
4. Press the Reset button to clear the interlock and turn the indicator off.
Watchdog Fault
The HPU Fault Status on the user interface panel displays Watchdog Fault if the watchdog timer stops
operating properly. A watchdog fault causes the HPU to shutdown. Perform the following procedure to attempt
to recover from this fault.
1. Turn the power disconnect switch on the main enclosure to off.
2. Wait at least 60 seconds, then close the power disconnect switch.
3. From the Startup Screen, press the Main Display button.
4. On the Main Display screen, press the Reset button.
5. If the Watchdog Fault condition does not clear, contact MTS Systems.
Series 505G2 SilentFlo™ Hydraulic Power Unit Product Information 63
Operation