Watlow 8LS Controller - Manual (Page 36)

28 8LS User’s Guide
Installation
Pid Control Relay Outputs
Typical ON/OFF, TP, DZC control outputs utilize external optically-
isolated solid-state relays. These relays use a 3 to 32vdc input for
control and can be sized to switch up to 100amps at 480vac. For larger
currents these relays can be used to drive contactors.
Primary Screw Terminal Outputs
The primary PID positive output for each loop is located on the screw
terminal blocks and labeled Ctl Out 1+ through Ctl Out 8+. The
negative side of the output is Logic Ground.
NOTE
Primary control outputs are a source supplying
5vdc when the output is On. They should be con-
nected to the positive (+) side of SSRs. Analog
outputs are positive with respect to logic ground.
Connections are made as follows:
SSR 1 SSR 2 I/P
+ - + + - -
Pin
#
2
3
1
4
Screw Terminal
Block 2
PID Ctl Out 1+
(TP or ON/OFF)
PID Ctl Out 2+
(TP or ON/OFF)
Logic Ground
PID Ctl Out 3+
(Analog 4-20 mAdc)