Emerson VSS, VSR, VSM service manual Solution

Slide Valve Actuator Trouble Shooting Guide

Problem

The motor runs sporadically

Reason	Solution
Bad thermal switch	Replace the actuator.
Any of the reasons listed in “The	See above.
motor will not move in either direc-
tion”

The motor runs but output shaft will not turn

Stripped gears inside the gear mo-	Replace the actuator.
tor or the armature has come un-
pressed from the armature shaft

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.

Flash Pattern	Meaning
*=ON
_=OFF
*_*_*_*_*_*_*_*_*_*_*_	Calibration step 1
*___*___*___*___*___	Calibration step 2
*__*________________	This indicates a zero span. This error can only occur during calibration. The typical
	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 procedure. 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.

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