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Effective 2018-11-02
Bulletin No. DA30D-A
Drawing No. LP1078
CONNECTING POWER
The DA30D requires a 10-30 VDC power
supply. A pluggable power block is provided
to connect the 24 VDC. There are three screw
terminals. Strip and connect the wire
according to the terminal block specifications
on Page 2. Connect the positive lead to the
plus (+) screw and the negative lead to the
minus (-) screw.
Please take care to observe the following points:
– Mount the power supply close to the unit, with usually not more than
6 feet (1.8 m) of cable between the supply and the operator
interface. Ideally, the shortest length possible should be used.
– The wire used to connect the operator interface’s power supply
should be at least 22-gage wire suitably rated for the temperatures
of the environment to which it is being installed. If a longer cable run
is used, a heavier gage wire should be used. The routing of the
cable should be kept away from large contactors, inverters, and
other devices which may generate significant electrical noise.
– A power supply with an NEC Class 2 or Limited Power Source (LPS)
and SELV rating is to be used. This type of power supply provides
isolation to accessible circuits from hazardous voltage levels generated
by a mains power supply due to single faults. SELV is an acronym for
“safety extra-low voltage.” Safety extra-low voltage circuits shall exhibit
voltages safe to touch both under normal operating conditions and after
a single fault, such as a breakdown of a layer of basic insulation or after
the failure of a single component has occurred. A suitable disconnect
device shall be provided by the end user.
CONNECTING TO EARTH GROUND
The third pin of the power connector is chassis ground for the unit.
Your unit should be connected to earth ground. Steps should be taken
beyond connecting to earth ground to eliminate the buildup of
electrostatic charges.
The chassis ground is not connected to signal common of the unit.
Maintaining isolation between earth ground and signal common is not
required to operate your unit. But, other equipment connected to this unit
may require isolation between signal common and earth ground.
To
maintain isolation between signal common and earth ground care must
be taken when connections are made to the unit.
For example, a power
supply with isolation between its signal common and earth ground must
be used. Also, plugging in a USB cable may connect signal common and
earth ground.
1
1
USB’s shield may be connected to earth ground at the host. USB’s
shield in turn may also be connected to signal common.
MODULE
INSTALLATION
Remove module plug and attach module to DA30D. Torque screws to
6.0 pound-force inch [96 ounce-force inch] (0.68 Nm).
EMC
INSTALLATION
GUIDELINES
Although Red Lion Controls products are designed with a high degree
of immunity to Electromagnetic Interference (EMI), proper installation and
wiring methods must be followed to ensure compatibility in each
application. The type of the electrical noise, source or coupling method
into a unit may be different for various installations. Cable length, routing,
and shield termination are very important and can mean the difference
between a successful or troublesome installation. Listed are some EMI
guidelines for a successful installation in an industrial environment.
1. A unit should be mounted in a metal enclosure, which is properly
connected to protective earth.
2. Use shielded cables for all Signal and Control inputs. The shield
connection should be made as short as possible. The connection point
for the shield depends somewhat upon the application. Listed below
are the recommended methods of connecting the shield, in order of
their effectiveness.
a. Connect the shield to earth ground (protective earth) at one end
where the unit is mounted.
b. Connect the shield to earth ground at both ends of the cable, usually
when the noise source frequency is over 1 MHz.
3. Never run Signal or Control cables in the same conduit or raceway with
AC power lines, conductors, feeding motors, solenoids, SCR controls,
and heaters, etc. The cables should be run through metal conduit that
is properly grounded. This is especially useful in applications where
cable runs are long and portable two-way radios are used in close
proximity or if the installation is near a commercial radio transmitter.
Also, Signal or Control cables within an enclosure should be routed as
far away as possible from contactors, control relays, transformers, and
other noisy components.
4. Long cable runs are more susceptible to EMI pickup than short cable runs.
5. In extremely high EMI environments, the use of external EMI
suppression devices such as Ferrite Suppression Cores for signal and
control cables is effective. The following EMI suppression devices (or
equivalent) are recommended:
Fair-Rite part number 0443167251 (Red Lion Controls #FCOR0000)
Line Filters for input power cables:
Schaffner # FN2010-1/07 (Red Lion Controls #LFIL0000)
6. To protect relay contacts that control inductive loads and to minimize
radiated and conducted noise (EMI), some type of contact protection
network is normally installed across the load, the contacts or both. The
most effective location is across the load.
a. Using a snubber, which is a resistor-capacitor (RC) network or metal
oxide varistor (MOV) across an AC inductive load is very effective at
reducing EMI and increasing relay contact life.
b. If a DC inductive load (such as a DC relay coil) is controlled by a
transistor switch, care must be taken not to exceed the breakdown
voltage of the transistor when the load is switched. One of the most
effective ways is to place a diode across the inductive load. Most
Red Lion products with solid state outputs have internal zener diode
protection. However external diode protection at the load is always a
good design practice to limit EMI. Although the use of a snubber or
varistor could be used.
Red Lion part numbers: Snubber: SNUB0000
Varistor: ILS11500 or ILS23000
7. Care should be taken when connecting input and output devices to the
instrument. When a separate input and output common is provided,
they should not be mixed. Therefore a sensor common should NOT be
connected to an output common. This would cause EMI on the
sensitive input common, which could affect the instrument’s operation.
Visit
www.redlion.net/emi
for more information on EMI guidelines,
Safety and CE issues as they relate to Red Lion products.
REMOVE MODULE PLUG
WARNING: Disconnect all power
to the unit before installing or
removing modules.
