804-R010-330 datasheet(23/32 Pages) MAGNETROL

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50-604 Kotron Model 804 Sentinel II RF Level Transmitter

3.0

Reference Information

3.1

Troubleshooting

Caution: In hazardous areas, do not remove housing until power is

disconnected and atmosphere is determined to be

safe.The Sentinel II contains a comprehensive diagnostics

system that can assist in locating the cause of a specific

fault. This system also allows the user to test the 4–20 mA

and discrete (relay) outputs to ensure satisfactory opera-

tion of the system. The following section defines each

function of the diagnostics system:

3.1.1 Test Relays

The Test Relays menu provides a controlled contact

closure for each relay to test its integrity. A password is

required.

3.1.2 Test 4–20 Output

The 4–20 Loop Output menu provides a means for testing

the 4–20 mA output. Once the desired loop current is

entered, the Model 804 will drive the output loop to this

current value.

3.1.3 Signal Values

The Signal Values menu provides a means of examining

the signals between the probe and the CCO (Capacitance

Controlled Oscillator). The three signals are:

3.1.3.1 CCO int. cap.

This signal represents the time period of the oscillator

using the internal test capacitor. This fixed capacitor is

switched into the circuit to test the oscillator. A value of

approximately 475 and 525 µsec. is acceptable.

3.1.3.2 Open probe

This signal represents the time period of the oscillator with

no capacitor attached (the probe and the fixed capacitor

are switched out of the circuit). A value between 150 µsec.

and 250 µsec. is acceptable.

3.1.3.3 CCO probe

This signal represents the time period of the oscillator

using the probe’s capacitance The minimum should be

equal to or greater than the open probe value; the maxi-

mum should not exceed 70,000 µsec.

804-R010-330 датащи(PDF) 23 Page - Magnetrol International, Inc.