Sierra 240-VTP, 241-VTP instruction manual Symptom No Output

Series 24-HP Instruction Manual		Chapter 4 Troubleshooting & Repair
	% change to final value	= 100	(1 – e(-1/TC))
	in one second

4.The

vortex coefficient Ck may be incorrectly set. The Ck is a value in the equation used to determine if a frequency represents a valid vortex signal given the fluid density and signal amplitude. In practice, the Ck value controls the adaptive filter, fi, setting. During flow, view the f and fi values in the first column of the hidden diagnostics. The fi value should be approximately 10- 20 % higher than the f value. If you raise the Ck setting in the Calibration Menu, then the fi value will increase. The fi is a low pass filter, so by increasing it or lowering it, you can alter the range of frequencies that the meter will accept. If the vor- tex signal is strong, the fi value will increase to a large number

– this is correct. Note: at high frequencies, the display may not be able to display all the digits of the fi value (for example, 114 may be displayed and the actual value is 1140).

Symptom: No Output

1.For remote mounted electronics, carefully check all the wiring connections in the remote mount junction box. There are 18 connections that must be correct, verify each color (black and red), shield, and wire number.

2.Turn on the pressure and temperature display in the Display Menu and verify that the pressure and temperature are correct.

3.Using ESD precautions and hazardous area precautions, re- move the electronics enclosure window cover. Disconnect the vortex sensor from the analog board (the analog board is the first board below the microprocessor (display) board. Measure the resistance from each outside pin to the meter ground - each should be open. Measure the resistance from the center pin to the meter ground – this should be grounded to the meter. With the sensor still disconnected, go to the first column of the hid- den diagnostics and display the vortex shedding frequency, f. Hold a finger on the three exposed pins on the analog board. The meter should read electrical noise, 60 Hz for example. If all readings are correct, re-install vortex sensor wires.

4.Verify all meter configuration and troubleshooting steps previ- ously described. There are many possible causes of this prob- lem, consult factory if necessary.

IM-24-HP 4-7