DH Instruments E-DWT-H, Руководство по эксплуатации и обслуживанию

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E-DWT-H OPERATION AND MAINTENANCE MANUAL
© 2009 DH Instruments, a Fluke Company Page 22
The Valve Position LEDs (7, 9) indicate the position in which the valve knob should be set based on the
current Q-RPT selection on the RPM4-E-DWT. If the Hi Q-RPT is selected, the LO Q-RPT SHUT OFF LED
(7) is lit indicating that the valve knob should be turned fully CW to close the valve, protecting the Lo Q-RPT
from high pressure. If the Lo Q-RPT is selected, the
LO Q-RPT ACTIVE LED (9) is lit indicating that the valve
knob should be turned fully CCW to open the valve, connecting the Lo Q-RPT to the test pressure.
Note
The E-DWT-H Lo Q-RPT shut off valve (8) must always be in the closed position
(knob fully CW) when operating at pressure greater than the maximum pressure of
the Lo Q-RPT.
The CAUTION LO Q-RPT ACTIVE LED (10) is used to indicate that the Lo Q-RPT is active and provide
an alert when the Lo Q-RPT is active but a Hi Q-RPT range is selected on the RPM4-E-DWT.
The CAUTION LO Q-RPT ACTIVE LED (10) is driven by the value of pressure currently measured by the
Lo Q-RPT , it is not driven by the valve position as there is no sensing of the valve position.
The CAUTION LO Q-RPT ACTIVE LED (10) has three possible conditions:
•
LED is OFF: The Lo Q-RPT is NOT active. The Lo Q-RPT is considered active when it measures a
pressure greater than about 100 psig (700 kPa).
•
LED ON continuously: The Lo Q-RPT IS active (exposed to pressure greater than 100 psi) and the
Lo Q-RPT is selected on the RPM4-E-DWT. The LED is lit as a reminder that the Lo Q-RPT is active
and pressure over its maximum working pressure (maximum depends on Lo Q-RPT range) should
not be applied.
•
LED is flashing ON/OFF accompanied by high frequency beeps and <!!LO Q-RPT ACTIVE!!>
displayed by RPM4-E-DWT: Lo Q-RPT IS active and the Hi Q-RPT is selected on RPM4-E-DWT.
The Lo Q-RPT should NOT be exposed to pressure when the Hi Q-RPT is selected. Exposing the Lo
Q-RPT to pressures for which the Hi Q-RPT is normally used, will overpressure and damage the Lo
Q-RPT Vent pressure from the RPM4-E-DWT and shut off the Lo Q-RPT with the Lo Q-RPT shut off
valve before continuing to use the Hi Q-RPT.
Note
If the Hi Q-RPT is selected with the Lo Q-RPT active, RPM4-E-DWT goes into an
alarm condition to avoid accidental overpressure of the Lo Q-RPT while using a Hi
Q-RPT. The pressure on the Lo Q-RPT must be reduced to less than 100 psig (700
kPa) so that the CAUTION LO Q-RPT ACTIVE LED is OFF before shutting the Lo
Q-RPT shut off valve and selecting the Hi Q-RPT.
The E-DWT-H Lo Q-RPT pressure relief valve (Figure 12, Ref 4) is set to open at approximately 110% of
the RPM4-E-DWT Lo Q-RPT maximum range. When the pressure applied to the Lo Q-RPT reaches the
relief valve setting, the pressure relief valve will open exhausting oil to the reservoir and reduce pressure.
Prior to opening the pressure relief valve, the RPM4-E-DWT will have gone into an overpressure
condition (see Section 3.8.4.1). If an overpressure condition occurs, reduce pressure as soon as
possible. The pressure relief valve will reseat automatically and close when pressure is reduced.
Note
Do NOT overpressure the Lo Q-RPT. The Lo Q-RPT may be damaged beyond
repair by pressure greater than its maximum working pressure. Q-RPT damage
from overpressure is logged in user and factory maintenance pages and is not
covered by the product warranty. The E-DWT-H pressure relief valve should only
be considered a last resort means of protecting the Lo Q-RPT and it does not
guarantee that the Lo Q-RPT will not be damaged by overpressure. Following
proper operating procedures, the Lo Q-RPT should never be over pressured.