MTS Model 506-62-72 Hydraulic Power Supply - Manual (Page 6)

1-2 Introduction
Pressure accumulation The pump-outlet pressure accumulator smooths the HPS output and
provides additional hydraulic pressure for high instantaneous flow
demands. It is precharged with dry nitrogen to a pressure proportional
to HPS output pressure. The optional slow turn-on accumulator slows
the rate at which the backup relief valve shifts from low to high
pressure.
Temperature control A temperature gage indicates hydraulic fluid temperature. An
oil-to-water heat exchanger controls the fluid temperature. When the
temperature exceeds a preset limit, a temperature sensitive switch
turns off the HPS and lights the front panel Fluid Over-Temperature
indicator.
Fluid level indication A transparent gage indicates the level of hydraulic fluid in the HPS
reservoir. A low-level switch automatically turns off the HPS and
lights the front panel Low Fluid Level indicator if hydraulic fluid
drops below a preset level.
Programmable logic
controller The PLC (programmable logic controller) located in the starter
assembly performs logic functions. The I/O (input/output) section of the
PLC provides an interface for various signals received from or sent to
external devices.
1.2 Specifications
Cooling water
specifications The required water pressure between the input and the output of the
heat exchanger is 30 to 45 psi (0.2 to 0.3 MPa). The maximum allowable
pressure is 120 psi (0.8 MPa). The flow rate (
±
20%) at a given
temperature is shown in the table below.
Table 1-1. Cooling Water Requirements
Cooling Water Inlet Required Water Flow
Temperature 506.62 506.72
60
°
F (15.5
°
C) 30 gpm (114 L/min) 35 gpm (132 L/min)
65
°
F (18.5
°
C) 35 gpm (132 l /min) 42 gpm (159 L/min)
70
°
F (21.0
°
C) 40 gpm (151 L l /min) 51 gpm (193 L/min)
75
°
F (24.0
°
C) 40 gpm (151 L/min) 67 gpm (254 L/min)
80
°
F (26.5
°
C) 45 gpm (170 L/min) 90 gpm (341 L/min)
85
°
F (29.5
°
C) 63 gpm (238 L/min) 120 gpm (454 L/min)