Pressure Connections; Supply Connection; Output Connection; Instrument Connection - Emerson Fisher 3660 Instruction Manual

Instruction Manual
Form 5265
March 2006

Pressure Connections

Installing a Type 3660 or 3661 positioner requires
tubing and pressure fittings. The fittings, tubing, and
mounting parts required depend on the type number
and optional equipment, such as filter/regulator and
bypass valve. See figure 15 for the location of the
positioner pressure connections.
WARNING
The positioner is capable of providing
full supply pressure to connected
equipment. To avoid personal injury
and property damage caused by parts
bursting from system overpressure,
make sure the supply pressure never
exceeds the maximum safe working
pressure of any connected equipment.

Supply Connection

WARNING
Severe personal injury or property
damage may occur if the instrument
air supply is not clean, dry and oil-free.
While use and regular maintenance of
a filter that removes particles larger
than 40 microns in diameter will
suffice in most applications, check
with a Fisher field office and Industry
Instrument air quality standards for
use with corrosive air or if you are
unsure about the proper amount or
method of air filtration or filter
maintenance.
3660 and 3661 Positioners
CAUTION
The O-rings used in Type 3660 and
3661 positioners are made of EPDM
(ethylene propylene). Use a clean, dry,
oil-free air supply with instruments
containing EPDM components. EPDM
is subject to degradation when
exposed to petroleum-based
lubricants.
Connect a clean, dry, oil-free air source to the supply
connection of the positioner. Use 3/8-inch tubing or
1/4-inch pipe for the supply line. A supply air filter or
a filter regulator capable of removing particles 40
microns in diameter is recommended. The supply
pressure should not exceed the following limits:
1. For the positioner, do not exceed the maximum
pressure rating of 6.2 bar (90 psig).
2. For actuator pressure, refer to the appropriate
actuator instruction manual for maximum allowable
pressures.
3. For the valve body assembly, do not exceed the
maximum allowable thrust of the specific valve.

Output Connection

Connect the OUTPUT connection to the actuator
diaphragm casing connection. Use 3/8-inch,
1/4-inch, or 6 mm tubing, or 1/4-inch pipe between
the actuator and the positioner.

Instrument Connection

Connect the control device output to the positioner
INSTRUMENT connection. Use 3/8-inch tubing to
1/4-inch pipe.
The Type 3661 electro-pneumatic positioner
requires a 4 to 20 milliampere dc current input signal
from the control device. For connections to the Type
3661, refer to the Electrical Connections for Type
3661 Positioners section.
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