Manual

16
BRAY Series 70 Servo Pro
Operation and Maintenance Manual
notice
A torque switch that is broken, improperly wired,
or missing from the actuator can result in an open
contactwhichwillbeinterpretedbytheServoProas
theactuatorbeingatitsmaxtorquelimit.
Iftheoptionaltorqueswitchesarenotinstalled,select
TorqueSwitchDisablebysettingCongurationswitch
10toON.
caution
Donotconnectanyhighvoltagepowertothetorque
limitswitchterminalsasdamagecouldresult.
5.1.7 feedback Potentiometer
The Servo Pro uses the signal from the internal
feedback potentiometer to determine the current
actuator position.
Thewiringtothefeedbackpotentiometerisconnected
at the factory and should not require any adjustment
bythecustomer.Ifaeldrepairisrequired,followthe
instructionsbelow:
5.1.7.1 feedback Potentiometer
i
nstallation and calibration
1. Installtheinternalfeedback potentiometer next to
theactuatorindicatorshaftusingthetwothreaded
mountingholesprovided.
2. Thepotentiometerassemblymustbemountedinthe
correctorientationinordertosuccessfullycalibrate
theServoPro.
3. Removetheindicatorrotorfromtheindicatorshaft
sothatthedriveslotonthetopisvisible.
4. Engage the handwheel (pulling it fully outward)
andmanually move theactuatorto the fullyopen
(counterclockwise)position.
5. Usetheblackfeedbackpotknobtorotatetheblack
feedbackpotcamuntiltheraisedgreenribonthe
potgear(seeFigure4below)isdirectlyin-linewith
theslotonthetopoftheindicatorshaft.
6. Theactuatorisnowreadyforthecalibrationprocedure
describedinSection3.1.
notice
The wiring of the feedback pot is critical to proper
operation.
Connecttheorangewirefromthewiperpinofthepot
tothemiddleterminal.
Connectthegraywirefromthexedpinofthepotthat
isclosesttothewiperpintothe+5Vterminal.
Connectthewhitewirefromthe xedpinofthepot
thatisfarthestfromthewiperpintotheCOMterminal.
Connectavoltmeterbetweenthemiddleterminaland
the COMMON terminal. Apply power to the Servo
Pro,movetheactuatortothefullyopenposition,and
the reading should be close to +5 VDC. Move the
actuatortothefullyclosedposition,andthereading
shouldbecloseto0VDC.
caution
Donotconnectanyhighvoltagepowertothefeedback
potterminalsasdamagecouldresult.
figure 4: feedback Pot mounting and Positioning.
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