MTS Series 505G2 SilentFlo Hydraulic Power Unit Model 505G2-30 User Manual
Page 48

Model 505G2.20 - 505G2.30 SilentFlo™ HPU
48
Resetting the Thermal Overloads and Circuit Breakers
Operation
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 and Circuit Breakers
The electrical power feed line for each pump motor has a circuit breaker with
integrated thermal overload switch in the main electrical enclosure. If any pump
motor draws too much current, its thermal overload switch trips and disconnects
that pump motor from the electrical power feed.
Additional protection is provided by circuit breakers. A tripped thermal overload
or circuit breaker indicates a potential short circuit, too much heat in the
electrical box, or a component failure (mechanical or electrical). Before
operating the HPU, locate and remedy the cause of the tripped thermal overload
or circuit breaker.
Reset the thermal overload switches or circuit breakers as follows:
1. Turn the main disconnect switch counterclockwise to remove power from
the electrical control box.
Increase
Decrease