Wiring Connections; Signal Wiring; Thermocouple (Cn63100); Rtd (Cn63100) - Omega CN63100 Series User Manual

1/16 din temperature/process controllers
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WIRING CONNECTIONS

After the unit has been mechanically mounted, it is ready to be wired. All
wiring connections are made to the rear screw terminals. When wiring the
unit, use the numbers on the label and those embossed on the back of the case,
to identify the position number with the proper function.
All conductors should meet voltage and current ratings for each terminal.
Also cabling should conform to appropriate standards of good installation,
local codes and regulations. It is recommended that power supplied to the unit
(AC or DC) be protected by a fuse or circuit breaker. Strip the wire, leaving
approximately 1/4" (6 mm) bare wire exposed (stranded wires should be
tinned with solder). Insert the wire under the clamping washer and tighten the
screw until the wire is clamped tightly.
Caution: Unused terminals are NOT to be used as tie points. Damage to the
controller may result if these terminals are used.

SIGNAL WIRING

Thermocouple (CN63100)

When connecting the
thermocouple, be certain that
the connections are clean and
tight, refer to Figure 4 for
terminal connections. If the
thermocouple probe cannot
be connected directly to the
controller, thermocouple wire
or
thermo couple
extension-grade wire must be
used to extend the connection
points (copper wire does not
work). Always refer to the
thermocouple manufacturer's
recommendations
for
mounting, temperature range,
shielding, etc. For multi-probe temperature averaging applications, two or
more thermocouple probes may be connected to the controller (always use the
same type). Paralleling a single thermocouple to more than one controller is
not recommended. Generally, the red wire from the thermocouple is negative
and connected to the controller's common.
Figure 4, Thermocouple Connection

RTD (CN63100)

When connecting the
RTD, be certain that the
connections are clean and
tight, refer to Figure 5 for
terminal connections. RTD
sensors h ave a h igher
degree of accuracy and
stability than thermocouple
sensors. Most RTD sensors
available are the three wire
type. The third wire is a
sense lead for canceling the
effects of lead resistance of
the probe. Four wire RTD
elements may be used by
leaving one of the sense
leads disconnected. Two wire RTD sensors may be used in either of two ways:
A) Attach the RTD to terminals #8 and #10. Install a copper sense wire of the
same wire gage as the RTD leads. Attach one end of the wire at the probe
and the other end to terminal #9. Complete lead wire compensation is
obtained. This is the preferred method.
B) Attach the RTD to terminals #8 and #10. Install a shorting wire between
terminals #9 and #10, as shown in Figure 5, RTD Connection. A
temperature offset error of 2.5°C/ohm of lead resistance exists. The error
may be compensated by programming a temperature offset.
Note: With extended cable runs, be sure the lead resistance is less than 15
ohms/lead. For thermocouple or RTD runs longer than 100 feet, convert the
signal to a current near the temperature probe. Current or 20 mA loop signals
are less susceptible to noise and signal loss than long thermocouple or RTD
runs. By converting the temperature signal, the CN63300 can be used in place
of a CN63100.
-5-
Figure 5, RTD Connection

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Cn63300 series

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