Samson 3767 - Adjusting the Position Transmitter

44 EB8355-2EN
Operation
5.4 Adjustingtheposition
transmitter
NOTICE
The starting point (zero) and upper
range value (span) must be set before
adjusting the position transmitter.
Dependingonthepositionofthemulti-pin
connector(symbolonconnector:>>or<>),
thefeedbacksignalcanbesettoeithera
rangeof4to20mAor20to4mAfor0to
100%travel.
Fig.15:Position transmitter
Zeropoint
Use the switches 1 and 2 to roughly set the
zero point and the ZERO potentiometer for
ne-tuning.Theadjustedvalueisalways
basedona4mAsignal.
Span
Use the switches 3 and 4 to roughly set the
span, i.e. the upper range value, and the
SPANpotentiometerforne-tuning.Thead-
justedvalueisalwaysbasedona20mA
signal.
Example:
Move the valve to the open position while
observingthepositiontransmittersignal.
If the signal does not move in the desired di-
rection,changethepositionofthemulti-pin
connector.
Adjustthezeropoint(4mA)andspan
(20mA)forthevalvepositionsaccordingto
Table10.
Table10: Position transmitter
Valve movement Observedfeedbacksignal Direction of signal Set zero/span to
OPEN
á
CLOSED
Signal increases á
OK
20mA ValveOPEN
4mA ValveCLOSED
NotOK
à Change connector's
position
4mA ValveOPEN
20mA ValveCLOSED
Signal drops â
OK
4mA ValveOPEN
20mA ValveCLOSED
NotOK
à Change connector's
position
20mA ValveOPEN
4mA ValveCLOSED