MTS Series 505 SilentFlo Hydraulic Power Unit Model 505-30 - Manual (Page 44)

Model 505.20 - 505.30 SilentFlo™ HPU 44
Resetting the Thermal Overloads
Operation
Note When the HPU is turned off, a solenoid valve also shuts off the flow of
water to the heat exchanger.
The valve is adjusted at MTS Systems Corporation to maintain the hydraulic
fluid temperature at 43°C (110°F). However, the temperature of your water may
require you to readjust the regulator.
To set the operating temperature of the hydraulic fluid:
1. Start the HPU and switch to high-pressure mode.
2. Observe the temperature gage as the hydraulic fluid temperature rises. Note
the temperature where the hydraulic fluid stabilizes.
3. Adjust the water-regulating valve. One full turn (360°) of the adjusting
screw produces a change in hydraulic fluid temperature a few degrees.
• Adjust the screw clockwise to decrease the operating temperature.
• Adjust counterclockwise to increase the operating temperature.
4. Note the effect after 15 minutes.
5. Repeat the previous two steps until the hydraulic fluid temperature stabilizes
between 43°C–49°C (110°F–120°F).
Resetting the Thermal Overloads
Each incoming electrical power feed line has a thermal overload switch. If any
line becomes too hot, its thermal overload switch trips and disconnects the
hydraulic power unit (HPU) from the electrical power feed.
Additional protection is provided by line fuses (FU1–FU3) and transformer fuses
(FU4–FU6). These cartridge-type fuses must be replaced with fuses of the same
size, type, and rating, which vary according to the voltage configuration.
Increase Decrease