Rosemount P300, Инструкция по установке и эксплуатации

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4-9
Validation Procedures
To perform a pressure switch test, refer to Figure 4-7 and Figure 4-8
above for connection diagrams and proceed as follows:
1. Ensure that the validator is off before making any connections.
2. Open the vent valve on the validator.
3. Connect the switch device intake to the reference pressure test
port using a pneumatic hose.
4. If the validator has a pressure/vacuum switch, set the selector
switch to + or – as required.
5. Connect the test leads as shown in the diagrams above for either
an externally powered or validator-powered test. Avoid contact
with the leads and terminals.
6. Turn on the validator.
7. Set the validator to
DUAL DISPLAY
mode,
PRESSURE
/
CURRENT
, by
pressing the
P
and
I
keys simultaneously.
8. Press the
ZERO
key to zero the display before applying pressure.
9. If monitoring normally open contacts:
a. Open the fine pressure adjuster to approximately half way.
b. Close the vent valve.
c. Pump up the pressure to just below the operating pressure of
the switch.
10. Screw in the fine pressure adjuster until the switch operates.
Operation is indicated by a current loop of 12 mA.
11. Record the operating pressure.
12. Screw the volume adjuster out until the switch operates again.
Operation is indicated by a loop current of zero.
13. Record the pressure at which the switch operates.
14. Open the vent valve to release pressure before disconnecting.
15. Remove presure and vent the transmitter, validator, and all lines
before disconnecting any pressure lines.
16. Remove pressure and open the vent valve before switching the
pressure/vacuum output, if the validator is equipped with one.
See Safety Messages on page 4-1 for complete warning information.