Bray 70 Series SERVO PRO - Manual (Page 16)

14
BRAY Series 70 Servo Pro
Operation and Maintenance Manual
switches 1, 2 and 3. Refer to the configuration Switch
Chart in Section 2.2.
The potentiometer command signal option is useful to
demonstrate an actuator equipped with a Servo Pro when
a 4-20 mA DC calibration device is unavailable.
caution
Do not connect any high voltage power to the command
signal input terminals as damage could result.
notice
Shielding
Signal/communication lines should be shielded. Shield
must be grounded at one end only, preferably at the
controller. Grounding the shield at more than one
location can introduce noise in the circuitry by forming
ground loops.
The command signal supplied to the Servo Pro must
be isolated from all other external circuits.
5.1.3 o
utPut
s
ignal
t
erminals
The Servo Pro supplies an output signal that represents
the current position of the actuator. The customer wires
the output signal to an input of their process controller.
The output signal has polarity that must be observed.
Connect the positive conductor of the output signal to the
OUTPUT (+) terminal. Connect the negative conductor of
the output signal to the OUTPUT (-) RETURN terminal.
The output signal has four different ranges selectable
through configuration switches. The available ranges are:
4-20 mADC
0-5 VDC
0-10 VDC
The output signal is sometimes called the Retransmission
signal, or position feedback signal.
The output signal is calibrated by the microprocessor at
the same time the command signal is calibrated.
caution
Do not connect any high voltage power to the output
signal terminals as damage could result.
The Servo Pro provides an active (powered) output
signal. Do not apply any additional power source to
this circuit.
notice
The output signal supplied by the Servo Pro is designed
to drive an impedance of approximately 250 Ω, up to
a maximum of 500 Ω.
The output signal should be isolated from all other
external circuits.
The process controller receiving the output signal should
be adjusted to allow for a +/- 2% variance.
There is no change in the output signal range if Reverse
Acting mode is selected. The output signal always
operates in Forward Acting mode.
5.1.4 H
andWHeel
s
WitcH
t
erminals
The Servo Pro monitors the position of the actuator manual
override handwheel through switches connected to the
handwheel terminals.
The wiring to the handwheel terminals is connected
atthe factory and should not require any adjustment by
the customer.
notice
If the actuator handwheel is engaged (pulled fully
outward) the Servo Pro cannot power the actuator
motor in either direction.
The actuator handwheel must be disengaged (pushed
fully inward) for the Servo Pro to power the actuator motor.
!
!