User guide

Watlow Series SD Limit ■ 14 ■ Chapter 2 Install and Wire
Figure 14a — Output 2 Solid-state Relay
SD_ L - _ _ K _ - _ _ _ _
• 0.5 A maximum, Form A.
• 24 to 240VÅ (ac).
• See Quencharc note.
• Minimum load current 10mA
• Maximum leakage current 100µA
• Not for use with direct current (dc).
• Output does not supply power...
Figure 14b — Output 2 Switched DC
SD_ L - _ _ C _ - _ _ _ _
• Maximum supply current 30 mAÎ (dc).
• Supply voltage 6 to 12VÎ (dc).
• Not recommended for switching mechanical relays.
• Output supplies power.
Figure 14c — Output 2 EIA/TIA-485
SD_ L - _ _ U _ - _ _ _ _
• Isolated [50VÎ (dc)]
• Half duplex
• For more communications information, see the Features chapter.
2
3
4
T+/R+ 3
T-/R- 4
Internal Circuitry
dc-
dc+
6 to 12V (dc)
Load
Switched DC
-
+
3
4
2
3
4
dc+ 3
dc- 4
Internal Circuitry
COM.
N.O.
Solid-state Relay
3
4
Solid-state Switch
2
3
4
3
4
normally open
common
Ó
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.
Quencharc Note:
Switching inductive loads (relay
coils, solenoids, etc.) with the
mechanical relay, switched dc or
solid-state relay output options
requires use of an R.C. suppres-
sor.
Watlow carries the R.C. sup-
pressor Quencharc brand name,
which is a trademark of ITW
Paktron. Watlow Part No. 0804-
0147-0000.
Note: To prevent ground loops,
isolation needs to be maintained
from input to output when using
switched DC or analog process
outputs.