6
®
User Instructions Logix 520MD - LGENIM0520-01 11/09
7 WiRing AnD gROUnDing gUiDELinES
Electrical connections:
signal cable with cable passage
(NPT or M20 x 1,5) to terminals 2 x 2,5 mm
input signal:
4 – 20 mA
nOTE:
Observe the minimum requirements of voltage
and equivalent electrical load: 10,0 VDC / 500
Ω
/ at
20 mA
The performance is ensured only for a minimum input cur-
rent of 3,6 mA.
For wiring, the following notes should be observed:
nOTE:
The input loop current signal to the Logix
520MD should be in shielded cable. Shields must
be tied to a ground at only one end of the cable to
provide a place for environmental electrical noise to
be removed from the cable. In general, shield wire
should be connected at the source. (Figure 2)
Connect the 4-20 mA current source to ter11 and
-12 (Figure 2).
grounding Screw
The grounding screw, located inside the positioner cover,
should be used to provide the unit with an adequate and
reliable earth ground reference. This ground should be tied
to the same ground as the electrical conduit. Additionally, the
electrical conduit should be earth grounded at both ends of
its run. The grounded screw must not be used to terminate
signal shield wires.
Compliance Voltage
(Figure 3)
Output compliance voltage refers to the voltage limit the
current source can provide. A current loop system consists
of the current source, wiring resistance, barrier resistance
(if present), and the Logix 520MD impedance. The Logix
520MD requires that the current loop system allow for a 10 VDC
drop across the positioner at maximum loop current.
6 TUbing POSiTiOnER TO ACTUATOR
After mounting has been completed, tube the positioner
to the actuator using the appropriate compression fitting
connectors:
Air connections
: 1/4” NPT (standard air connection)
Auxiliary power
: Pressurized air or permissible
gases, free of moisture and dust in according with
IEC 770 or ISA 7.0.01.
Pressure range:
1,5 – 6,0 bar (22 – 87 psi)
For connecting the air piping, the following notes should
be observed:
1. The positioner passageways are equipped with filters,
which remove medium and coarse size dirt from the
pressurized air. If necessary, they are easily accessible
for cleaning.
2. Supply air should meet IEC 770 or ISA 7.0.01 require-
ments. A coalescing filter should be installed in front of
the supply air connection Z. Now connect the air supply
to the filter, which is connected to the Logix 500si series
positioner.
3. With a maximum supply pressure of 6 bar (87 psi) a
regulator is not required.
4. With an operating pressure of more than 6 bar (87 psi),
a reducing regulator is required. The flow capacity of
the regulator must be larger than the air consumption
of the positioner (7 Nm
3
/hr @ 6 bar / 4,12 scfm @ 87
psi).
5. Connect the outlet connector Y of the positioner to the
actuator with tubing, independent of the action (direct
or reverse).
Figure 2: Wiring Diagram
Table 10: Connection Table
Connection
Description
+11
Input+ 4..20 mA
-12
Input- 4..20 mA
+31*
4..20 mA
-32*
Output– 4..20 mA
Limit switch 1 - separate board
Limit switch 2 - separate board
Y (0
⇒
)
Pneumatic output signal (outlet)
Z (0
⇐
)
Air supply
* 0ptional
Y
Z
Internal Housing
EARTH Terminal
4-20 mA Signal
Connect Shield at Source Ground
-
+
4-20 mA Current Source
Shielded Cable
