Red Lion CUB7T - Manual (Page 5)

5
5.0 w
iring
t
he
m
eter
WIRING OVERVIEW
Electrical connections are made to the #22 AWG colored wires protruding
from the rear of the unit. When using the optional terminal block, the #22 AWG
colored wires are cut off and electrical connections are made via screwless type
terminal block. All conductors should conform to the meter’s voltage and
current ratings. All cabling and wire terminations should conform to appropriate
standards of good installation, local codes and regulations. It is recommended
that the backlight power supplied to the meter (DC or AC) be protected by a fuse
or circuit breaker.
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 (RLC# FCOR0000)
TDK # ZCAT3035-1330A
Steward # 28B2029-0A0
Line Filters for input power cables:
Schaffner # FN610-1/07 (RLC# LFIL0000)
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.
Snubber: RLC# SNUB0000.
USING THE COLOR CODED WIRES
The low voltage input units will contain three or four color coded wires
depending on the backlight power requirements.
The high voltage input units will contain (2) orange wires and an additional
two or three wires depending on the backlight power requirements.
The tables define the function of each colored wire.
LOW VOLTAGE INPUT
Wire Colors
WHITE BLUE BLACK RED
Low Voltage Input Reset Common +Backlight Power
HIGH VOLTAGE INPUT
Wire Colors
ORANGE ORANGE BLUE BLACK RED
High Voltage
Input
High Voltage
Input
Reset Common
+Backlight
Power
TERMINAL BLOCK OPTION
1 2 3 4 5 1 2 3 1 2 3 4
CONNECTIONS: Wire clamping terminals
Wire Strip Length: 0.275" (7 mm)
Wire Gage: 24-16 AWG copper wire