Dwyer 275 - Manual (Page 3)

5. Once the fork lever position is set, lock the check nuts on the bottom
of the fork lever by turning clockwise. Set the upper height of the fork
lever to 0.24 to 0.43”(6 to 11 mm) lower than the upper height of the
bracket.
6. Attach Series 275 unit to the bracket. Fix the clamping pin on the
main shaft center of the Series 275 into the hole of the fork lever.
Insert the connection bar attached on the main shaft lever into the
fork lever slot to be locked by the fork lever spring. This is to fit the
main shaft of the Series 275 to the center of the actuator stem. If they
are not fitted correctly, too much force on the main shaft will greatly
reduce product durability.
7. Attach Series 275 base and the bracket with hex bolts and plate
washers. It is best to lock the bracket and Series 275 together by
inserting four bolts after checking the position.
PIPING CONNECTION
Note:
1. To prevent ingress of moisture, oil and dust, give careful
consideration to the choice of supply pressure compressor and
piping.
2. It is recommended to attach filter or air filter regulator in front of the
supply port of the Series 275 unit.
Conditions of Supply Pressure
1. Dry air with a dew point that is at least 50°F (10°C) lower than that of
the ambient temperature.
2. Free from solid particles. Result of being passed through 5 micron or
finer filter.
3. Does not contain oil or lubricating oil.
4. Comply with ANSI/ISA-57.3 1975(R1981) or ISA S7.3-1975(R1981).
5. Not used beyond the range of 20 to 100 psi (140 to 689 kPa).
6. Set supply pressure of air filter regulator to 10% higher than
operating pressure of actuator.
Conditions of Pipe
1. Remove foreign objects from inside of pipe.
2. Do not use squeezed or broken pipe.
3. To maintain flow rate of Series 275, use a pipe with inner diameter
greater than 0.24˝ (6 mm) (outer diameter 0.39˝ (10 mm)).
Piping Connection With Actuator
Series 275 can operate as either single or double acting actuators.
Single Acting Actuator
To operate a single acting actuator, connect OUT1 port to actuator
supply pressure port. Close off the OUT2 port with the supplied 1/4˝
NPT plug.
Double Acting Actuator
For the Series 275 double acting type, OUT1 and OUT2 ports are used.
Power Connection
Note:
1. Before connecting terminal, power must be shut off.
2. Use ring type terminal against oscillation, impact, etc.
3. Series 275 positioners use 4 to 20 mA DC for power. Minimum
supply current is 3.2 mA (standard type) and 3.8 mA (HART ® type).
Maximum supply current must not exceed 24 mA.
4. In order to protect the Smart Positioner, the ground terminals should
be grounded.
5. Use twisted cable with conductor sectional area at least 0.0019 in 2
(1.25 mm 2 ), and suitable for 600V as on conductor table of NEC
Article 310. Outer diameter of cable should be 0.25 to 0.39˝ (6.35 to
10 mm). Use shielded wire against electromagnetic waves and
noise.
6. Do not install the cable near equipment such as a high-capacity
transformer or motor.
page 3
Installation position of fork lever
Fitting the pin on the Series 275 main shaft into fork lever hole
6~11mm
Bracket
Fork Lever
Actuator
Piping connection example of Series 275 with single acting actuator
LCD SCREEN
SMART POSITIONER
Piping connection example of Series 275 with double acting actuator
Terminal plate