Watlow Series SD Limit - Manual (Page 14)

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Warning:
Use National Electric (NEC) or
other country-specific standard
wiring and safety practices when
wiring and connecting this limit
to a power source and to electri-
cal sensors or peripheral de-
vices. Failure to do so may re-
sult in damage to equipment and
property, and/or injury or loss of
life.
Spring clamp wiring connector
note:
To insert the wire, push the wire
into the desired connection num-
ber, and it should automatically
lock into place. To remove the
wire, press and hold the orange
release tab with a small screw-
driver. Pull the wire out of the
connection. Solid or tinned wire
recommended.
Note: To prevent ground loops,
isolation needs to be maintained
from input to output when using
switched DC or analog process
outputs.
ç
WARNING: Process input may
not have sensor break protec-
tion. Outputs can remain full on.
Check your input settings.
Wa t l o w S e r i e s S D L i m i t
■
12
■
C h a p t e r 2 I n s t a l l a n d W i r e
Figure 12a — Thermocouple Input
(all model numbers)
Thermocouples are polarity sensitive. The negative lead (usually red) must be
connected to terminal 11.
• Input impedance: >20 M
Ω
Figure 12b — RTD Input (100
Ω
DIN curve 0.00385
Ω
/
Ω
/°C)
(all model numbers)
Terminals 8 and 11 must be shorted for a two-wire RTD. For three-wire RTDs,
the S1 lead (usually white) must be connected to terminal 10.
• Nominal excitation current: 390
µ
A
Figure 12c — 0 to 10VО О (dc) Process Input
(all model numbers)
• Input impedance 20 k
Ω
, dc only.
Figure 12d — 0 to 50mVО О (dc) Process Input
(all model numbers)
• Input impedance >20 M
Ω
, dc only.
6
8
9
10
11 10
11
+
-
6
8
9
10
11
9
11 +
-
3-wire RTD
6
8
9
10
11 S1 10
S3 11
S2 8
2-wire RTD
6
8
9
10
11 S1 10
11
S2 8
6
8
9
10
11 +10
-11