Resetting The Maximum Temperature Limit - Ametek 4207D Operating Manual

SECTION 3 – MAINTENANCE
3-2
Note: The system pressure will decrease as the oil temperature increases. For this
reason, adjust the system pressure when the oil temperature is at or near room
temperature.
1. Verify that the system temperature is below 80F (27C).
2. Turn the system On.
3. Place the cylinder control switch in the Up position.
4. Locate the relief valve adjustment and the system pressure
gauge.
5. Adjust the relief valve until the system pressure gauge
equals 2,600 200 psig.
6. Place the cylinder control switch in the Off position.
7. Tighten the relief valve lock nut.

Resetting the Maximum Temperature Limit

This system is equipped with a circuit that disables the hydraulic power unit if the oil
temperature exceeds 70C. The circuit must be manually reset for continued operation of the
system.
To reset the temperature limit, press the red reset button located on the right panel.
Use the following procedure to adjust the maximum temperature limit:
1. Turn the system Off.
2. Remove the back panel from the power unit.
3. Locate the temperature limit circuit board located on the left side of the enclosure
(viewed from the rear).
4. Locate the calibrated dial on the circuit board. Adjust the knob to a value of 70C.
5. To reset the temperature circuit, press the Red reset button located on the right panel.
6. To test the circuit, turn the system On then adjust the temperature set point below the oil
temperature. Verify that the relay opens and an LED illuminates. Adjust the set point
and press the Reset button.
Relief Valve Adjustment
Gauge