NOSHOK 1950 Series Compact Smart System 5-Digit Process Meter - Manual (Page 4)

WIRING OVERVIEW
Electrical connections are made via screw-clamp terminals located on the
back of the meter. All conductors should conform to the meter’s voltage and
current ratings. All cabling should conform to appropriate standards of good
installation, local codes and regulations. It is recommended that the power
supplied to the meter (DC or AC) be protected by a fuse or circuit breaker.
Strip the wire, leaving approximately 0.3" (7.5 mm) bare lead exposed
(stranded wires should be tinned with solder.) Insert the lead under the correct
screw-clamp terminal and tighten until the wire is secure. (Pull wire to verify
tightness.) Each terminal can accept up to one #14 AWG (2.55 mm) wire, two
#18 AWG (1.02 mm), or four #20 AWG (0.61 mm).
EMC INSTALLATION GUIDELINES
Although this meter is designed with a high degree of immunity to Electro-
Magnetic 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 the meter may be different for various
installations. The meter becomes more immune to EMI with fewer I/O
connections. Cable length, routing, and shield termination are very important
and can mean the difference between a successful or troublesome installation.
Listed below are some EMC guidelines for successful installation in an
industrial environment.
1. The meter should be mounted in a metal enclosure, which is properly
connected to protective earth.
2. Use shielded (screened) cables for all Signal and Control inputs. The shield
(screen) pigtail 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 only at the panel where the unit is mounted to earth
ground (protective earth).
b. Connect the shield to earth ground at both ends of the cable, usually when
the noise source frequency is above 1 MHz.
c. Connect the shield to common of the meter and leave the other end of the
shield unconnected and insulated from earth ground.
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 ran in 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.
4. Signal or Control cables within an enclosure should be routed as far as possible
from contactors, control relays, transformers, and other noisy components.
5. In extremely high EMI environments, the use of external EMI suppression
devices, such as ferrite suppression cores, is effective. Install them on Signal
and Control cables as close to the unit as possible. Loop the cable through the
core several times or use multiple cores on each cable for additional protection.
Install line filters on the power input cable to the unit to suppress power line
interference. Install them near the power entry point of the enclosure. The
following EMI suppression devices (or equivalent) are recommended:
Ferrite Suppression Cores for signal and control cables:
Fair-Rite # 0443167251
TDK # ZCAT3035-1330A
Steward # 28B2029-0A0
Line Filters for input power cables:
Schaffner # FN610-1/07
Schaffner # FN670-1.8/07
Corcom # 1 VR3
Note: Reference manufacturer’s instructions when installing a line filter.
6. Long cable runs are more susceptible to EMI pickup than short cable runs.
Therefore, keep cable runs as short as possible.
7. Switching of inductive loads produces high EMI. Use of snubbers across
inductive loads suppresses EMI.
4.0 W
IRING THE
M
ETER
4.1 POWER WIRING
DC Power
+9 to +28 VDC: +VDC
Power Common: -VDC
CAUTION: 9 to 28 VDC
power circuit is not isolated
from the signal circuit.
4.2 USER INPUT WIRING
Sinking Logic
USR COMM
USR
The user input of the meter is
internally pulled up to +9 to +28 V
with 10 K resistance. The input is
active when it is pulled low (<0 .7 V).
Connect external switching device between the
User Input terminal and User Input Common. }
4
The Plug-in cards are separately purchased option cards that perform specific
functions. The cards plug into the main circuit board of the meter
CAUTION: The Plug-in cards and main circuit board contain static
sensitive components. Before handling the cards, discharge
static charges from your body by touching a grounded bare
metal object. Ideally, handle the cards at a static controlled
clean workstation. Also, only handle the cards by the edges.
Dirt, oil or other contaminants that may contact the cards can
adversely affect circuit operation.
REMOVING THE REAR COVER
To remove the rear cover, locate the cover locking tab below the 2nd and 3rd
input terminals. To release the tab, insert a small, flat blade screwdriver between
the tab and the plastic wall below the terminals. Inserting the screwdriver will
provide enough pressure to release the tab locks. To replace the cover, align the
cover with the input terminals and press down until the cover snaps into place.
3.0 I
NSTALLING
P
LUG
-I
N
C
ARDS
Comms Card
Range Jumpers
Locking Tab
Setpoint Card