MEX-F

Final Control Elements

VALVE POSITIONER

Functions & Features
• I/I positioner for proportional valve position control in combination with electric actuator (100 V AC)
• Driving directly AC motor by solid state relay output
• Potentiometer or current feedback selectable
• Timer preventing frequent ON-OFF operation, protecting motor from overheating
• Retransmitted output standard
Typical Applications
• Single phase AC motor
• Loop powered isolator can be used for isolating between setpoint input signal and transmitter output signal
 

MODEL: MEX–F–[1][2][3][4]1–[5][6]

ORDERING INFORMATION

• Code number: MEX–F–[1][2][3][4]1–[5][6]
Specify a code from below for each of [1] through [6].
  (e.g. MEX-F-11111-B/B/Q)
• Specify the specification for option code /Q
  (e.g. /C01/S01/SET)

[1] OPERATION MODE SELECTOR

1: With
0: Without

[2] POSITION SETPOINT INPUT

1: 4 – 20 mA DC (Input resistance 100 Ω)
2: 1 – 5 V DC (Input resistance 200 kΩ min.)
3: 4 – 12 mA DC (Input resistance 100 Ω)
4: 12 – 20 mA DC (Input resistance 100 Ω)
For switching direct/reverse actions with split ranges, select "With" for Operation Mode Selector.

[3] POSITION FEEDBACK INPUT

1: Potentiometer
2: Current

[4] CONTROL OUTPUT

1: SSRs incorporated
2: Constant current driving external SSRs
3: 24 V AC dry contact

RE-TRANSMITTED OUTPUT

1: 4 – 20 mA DC

[5] POWER INPUT

AC Power
B: 100 V AC
C: 110 V AC
D: 115 V AC
F: 120 V AC
G: 200 V AC
H: 220 V AC
J: 240 V AC
DC Power
R: 24 V DC

[6] OPTIONS (multiple selections)

Brake Function
blank: Without
/B: With (incorporated SSRs control output type only)
Signal Indicator
blank: Without
/E: Front-mounted LCD meter
(with operation mode selector type only)
Other Options
blank: none
/Q: Option other than the above (specify the specification)

SPECIFICATIONS OF OPTION: Q (multiple selections)

COATING (For the detail, refer to our web site.)
/C01: Silicone coating
/C02: Polyurethane coating
/C03: Rubber coating
TERMINAL SCREW MATERIAL
/S01: Stainless steel
EX-FACTORY SETTING
/SET: Preset according to the Ordering Information Sheet
 (No. ESU-4623)

GENERAL SPECIFICATIONS

Construction: Plug-in
Connection: M3.5 screw terminals
Screw terminal: Chromated steel (standard) or stainless steel
Housing material: Flame-resistant resin (black)
Deadband adjustment: 2 – 20 % (front)
Timer adjustment: 1 – 30 sec. (front); 5 sec. minimum with breaking function
Isolation: Setpoint input or xmtr output or feedback input to control output to power (For external SSRs control output, non-isolated between control output and setpoint input etc.)
Zero adjustment (front)
 Potentiometer feedback: 0 – 25 %
 Current feedback: -10 – +10 %
Span adjustment (front)
 Potentiometer feedback: 75 – 100 %
 Current feedback: 90 – 110 %
Operation mode: Front-accessed DIP switches; failsafe operation (full-open, full-closed or stop) when there is no position input signal (approx. -12.5 %); direct/reverse re-transmitted output; direct/reverse control action
Electronic limit: Front-accessed potentiometers provided for Operation Mode Selector type
• Zero limit: Approx. -10 – +5 %
• Span limit: Approx. 95 – 110 %
Breaking function: Dynamic brake (applicable with 100 to 120 V AC motor only)
LCD meter: Indicating re-transmitted output signal; 0.1 % increments

INPUT SPECIFICATIONS

■ Setpoint Input
Input resistor: Attached to input terminals (0.5 W)
■ POSITION FEEDBACK INPUT
• Current: 4 – 20 mA DC
Input resistance: 20 Ω
• Feedback Potentiometer: 100 Ω – 10 kΩ
Minimum span: 50 % of total resistance
Excitation: 0.4 V DC

OUTPUT SPECIFICATIONS

■ Re-Transmitted Output: 4 – 20 mA DC
Load resistance: 750 Ω max.
■ Control Output
• SSR: Zero-cross fucntion; 80 – 264 V AC @ 0.1 – 1 A
The built-in SSR cannot drive 200 V AC motor (direct/reverse).
Leakage current at OFF: Approx. 10 mA @ 240 V
Remark: When driving relays with this control output, relays may operate erratically due to the leakage current at OFF of SSR. To avoid the problem, install a resistor (R) in parallel with the relay coil.
R < [Release Voltage] / ([Leakage Current at OFF] – [Release Current])
Output Operation: Refer to the figure at the end of this section.
■ Constant Current
Rating: 10 V DC, 10 mA ±10 % at ON;
0 mA at OFF
Output Operation: Refer to the figure at the end of this section.
• 24 V AC Dry Contact
Drive: Photo MOSFET relay
Rating: 27 V AC/DC @ 1 A
Leakage current at OFF: 1 mA @ 30 V AC
Output Operation: Refer to the figure at the end of this section

INSTALLATION

Power input
•AC: Operational voltage range: rating ±10 %,
50/60 ±2 Hz, approx. 3 VA
•DC: Operational voltage range: 24 V ±10 %, approx. 120 mA (ripple 10 %p-p max.)
Operating temperature: -5 to +60°C (23 to 140°F)
Operating humidity: 30 to 90 %RH (non-condensing)
Mounting: Surface or DIN rail
Weight: 300 g (0.66 lb)

PERFORMANCE in percentage of span

Position conversion accuracy: ±0.5 %
Re-transmitted output accuracy: ≤ 3 % excluding offset and deadband
Insulation resistance: ≥ 100 MΩ with 500 V DC
Dielectric strength: 2000 V AC @ 1 minute (setpoint input or xmtr output or feedback input to control output to power to ground)
(For external SSRs control output, non-isolated between control output and setpoint input etc.)

EXTERNAL VIEW

EXTERNAL DIMENSIONS unit: mm [inch]

TERMINAL ASSIGNMENTS unit: mm [inch]

SCHEMATIC CIRCUITRY & CONNECTION DIAGRAM

SIGNAL CHARACTERISTICS & DIRECT/REVERSE ACTIONS

EXPLANATIONS OF TERMS

• SSR (Solid State Relay)
Composed only of semiconductor parts, SSR is free from arc discharge or chattering which is typical with electromagnetic relays. It features excellent characteristics against vibration, physical impact or other environmental conditions.
• Zero-Cross Function
SSR with zero-cross function turns on when AC power voltage is near zero, creating delay of switching when input is provided in the middle of an wave cycle, thus limiting transient switching noise voltage and rush current.
• Photo MOSFET Relay
A kind of semiconductor relay which has advantages of both solid state relay and mechanical relay, thanks to its low ON-resistance characteristic. It also features high speed ON/OFF operation and low leak current.

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