Figure 10 -
Input Options “1”,
**2* & *3’, Thermo-
couple Wiring
Diagram.
Flgure
11 -
Input Options "2" &
"3" Process Input
Wlring
Diagram.
NOTE:
When using a 4-
2OmA process
Input, the input
impedance is
2 4 9 o h m s
lnput Options “1 “, “2” & “3”, Thermocouple Input
Terminals 18 & 20
Model # 98 – A - 1 _ _ - 0-0000
98_A-2 – – 0-0000
98_A-3-
0-0000
– –
NOTE:
You must use an isolated or ungrounded thermocouple if an external 4-20mA
output device with a non-isolated circuit common is connected to the 4-20mA
output.
Extenslon wire for thermocouples must be of the same alloy as the thermocouple
itself to limit errors.
These input connections
are used in conjunction with your units sensor
type. (Thermocouple and RTD only)
Input Options “2’ & “3”, Process or Remote Set Point Input
Terminals 15 - 17
Model #98_A - 2 _ _ 0 - 0000
98_A - 3 _ _ 0 - 0000
Jumper Terminal 16
to Terminal 17 when
using a 4-20mA
input.
.
0-5VDC 4-20mA INPUT
16
17
0-5VDC, 4-20mA INPUT
Input
Voltage
NOTE:
When using a process input such
as
O-5VDC or 4-2OmA, the rL and rH settings
scale the display to match the measured range of the process signal. When using
a 0-5VDC process input, the input impedance is 100K ohms.
An example of this is: A pressure transducer operates over a range of 0 - 300 PSI,
delivering a 4-20mA output signal for this range. By setting rL= 0 and rH = 300,
the Series 980/985 is now displayed as a direct reading of pressure.
14
WATLOW Series 980/985 User’s Manual
Install and Wire, Chapter
2
