MTS Series 505 SilentFlo Hydraulic Power Unit Model 505-11 - Manual (Page 45)

Adjusting the HPU Output Pressure Level
Model 505.07/.11 SilentFlo™ HPU Operation 45
The pump and motor are designed to operate below a specified pressure.
Setting the hydraulic pressure above 21 MPa (3000 psi) can damage the
pump and its motor.
Do not adjust the output pressure higher than 21 MPa (3000 psi).
Adjusting the HPU Output Pressure Level
1. Turn on high hydraulic pressure. Ensure that there are no flow demands by
the system.
2. Loosen the nut securing the output pressure control.
3. Monitor the hydraulic pressure gage located on the control manifold. Adjust
the output pressure as follows until the desired pressure is displayed.
• Turn the output pressure control clockwise to increase the pressure.
• Turn the output pressure control counterclockwise to decrease the
pressure.
Note If this pressure level is to be used for longer than 10 minutes, proceed to
“Adjusting the auto-cooling level” procedure.
4. Hold the output pressure control to prevent it from moving and tighten the
nut to secure it.
5. Check the hydraulic pressure gage to ensure that the desired hydraulic
pressure is being maintained.
Adjusting the Auto-Cooling Level
The auto-cooling function is integrated into the control manifold . During periods
of low flow demand from the external hydraulic circuit, this feature provides two
important benefits: a re-circulating flow that ensures hydraulic fluid filtering
whenever the unit is on, and safeguarding against hydraulic fluid over-
temperature. It functions by opening a hydraulic flow path through the fluid
conditioning circuit when external hydraulic demand for flow is low. When the
external demand increases, this feature closes the path to provide the full flow of
the HPU to the external demand.
The effective operating range of the auto-cooling circuit is between system
pressures of 14 MPa (2000 psi) to 21 MPa (3000 psi). In order for the Auto-
Cooling Valve to function properly, it must be re-adjusted anytime the output
pressure will be changed for longer than 10 minutes.
Note If the test condition requires a maximum pressure level of less than 14
MPa (2000 psi), consult MTS.
CAUTION