Dwyer LCR10 - Manual (Page 9)

April, 2003 Page 9 of 20 LCR10 IOM
Optional
Relay
Connections
Relay 2
Relay 1
Optional
Rela
y
J1
1 J2
1 J3
1 J3
J1
1 J2
J5
P1
P2
1 J3
1
2
3
4
1
2
3
4
1
2
3
4
RTD
T/C
Voltage/
Current
Note: Internal circuitry shown at
right of terminations, external
to the left.
1 J3
(Connected to
power input)
Figure 2-3 Input/Relay wiring - PCB layout
2-7 Thermocouple Input Wiring
Thermocouple input connections are shown in Figure 2-3. The correct type
of thermocouple extension lead-wire or compensating cable must be used
for the entire distance between the unit and the thermocouple, ensuring
that the correct polarity is observed throughout. Splices in the cable should
be avoided, if possible.
If the length of thermocouple plus the extension wire is too long, it may
affect the temperature measurement. A 400 ohms K type or a 500 ohms
J type thermocouple lead resistance will produce approximately 1 degree
C temperature error.