Emerson VSG, VSSG manual Flash Pattern, Meaning, 2. Slide Valve Actuator LED Blink Codes* 1 of

Section 6 • Troubleshooting

Slide Valve Actuators communicate problems discovered by internal diagnostics via LED blink codes. Only one blink code is displayed, even though it is possible that more than one problem has been detected.

Table 6-2. Slide Valve Actuator LED Blink Codes* (1 of 2)

Flash Pattern

Meaning

*=ON
_=OFF
*_*_*_*_*_*_*_*_*_*_*_	Calibration step 1
*___*___*___*___*___	Calibration step 2
	This indicates a zero span. This error can only occur during calibration. The typi-
	cal cause is forgetting to move the actuator when setting the upper limit of the
	span. If this is the case, press the blue button to restart the calibration proce-
	dure. This error can also occur if either or both of the slotted optocouplers are
	not working. If this is the case, the slide valve actuator will have to be replaced.
	The operation of the slotted optocouplers is tested as follows:
*__*________________	1. Manually rotate the motor shaft until the aluminum photochopper fence is
	not blocking either of the optocoupler slots.
	2. Using a digital multi-meter, measure the DC voltage between terminal 3 of
	the small terminal block and TP1 on the circuit board (see Note 1). You should
	measure between 0.1 and 0.2 Volts.
	3. Next, measure the DC voltage between terminal 3 and TP2 on the circuit
	board. You should measure between 0.1 and 0.2 Volts.
	This indicates a skipped state in the patterns generated by the optocouplers as
	the motor moves. This error means that the slide valve actuator is no longer
	transmitting accurate position information. The actuator should be recalibrated
	as soon as possible. This code will not clear until the actuator is recalibrated.
	This code can be caused by:
*__________________	1.	The motor speed exceeding the position sensors ability to measure it
	at some time during operation. A non-functioning motor brake is usually to
	blame.
	2.	The actuator is being operated where strong infrared light can falsely
	trigger the slotted optocouplers, such as direct sunlight. Shade the actuator
	when the cover is off for service and calibration. Do not operate the actuator
	with the cover off.

VSG/VSSG • Installation, Operation and Maintenance Manual •Vilter/Emerson • 35391SSG 6 – 3