Position Switch Circuit; Maintenance - Emerson Fisher 4200 Instruction Manual

4200 Transmitters
March 2011
signal flows between the (-) terminal on TB3 and the power supply common. This prevents the relay coil switching
currents from appearing on the 4 to 20 mA output.

Position Switch Circuit

A regulated voltage is setup to power the position switch circuit. The position switch circuit senses the position of the
potentiometer and triggers the appropriate position switch relay (K1 or K2, figure 10) when travel reaches the trip
points established by the adjustments. The 4215 transmitter uses dual potentiometers which allows individual
potentiometers for the transmitter circuit and the position switch circuit.
Figure 10. Schematic Diagram for the Field Printed Wiring Board
1
NOTE:
1
RELAYS K1 AND K2 ARE SHOWN IN THE DE‐ENERGIZED POSITION (TRIPPED POSITION).
29A6206‐D / DOC

Maintenance

WARNING
To avoid personal injury or property damage from the sudden release of pressure:
D Always wear protective clothing and eyewear when performing any maintenance operations.
26
1
Instruction Manual
D200354X012