Watlow Series SD31 PID with Optional Countdown Timer - Manual (Page 12)

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Warning:
Use National Electric (NEC) or
other country-specific standard
wiring and safety practices when
wiring and connecting this con-
troller to a power source and to
electrical sensors or peripheral
devices. Failure to do so may re-
sult in damage to equipment and
property, and/or injury or loss of
life.
Quencharc Note:
Switching pilot duty inductive
loads (relay coils, solenoids,
etc.) with the mechanical relay
or solid-state relay output op-
tions requires use of an R.C.
suppressor.
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.
Figure 10a — Output 2 Solid-state Relay
SD31 - _ _ K _ - _ _ _ _
• Form A contact
• 0.5 A maximum, resistive
• 20 VA pilot duty, 120/240V Å (ac), inductive
• See Quencharc note
• 24 to 240V Å (ac)
• Minimum load current 10 mA
• Maximum leakage current 100 µA
• Not for use with direct current (dc)
• Output does not supply power
Figure 10b — Output 2 Switched DC
SD31 - _ _ C _ - _ _ _ _
• Maximum supply current 30 mA Î (dc)
• Supply voltage 6 to 12V Î (dc)
• Not recommended for switching mechanical relays
• Output supplies power
Figure 10c — Output 2 EIA/TIA-485
SD31 - _ _ U _ - _ _ _ _
• Isolated [50 V Î (dc)]
• Half duplex
• For more communications information, see the Features chapter
2
3
4
T+/R+ 3
T-/R- 4
Internal Circuitry
dc-
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
Wa t l o w S e r i e s S D 3 1
■
10
■
C h a p t e r 2 I n s t a l l a n d W i r e