Watlow 8LS Controller - Manual (Page 115)

Appendix B: 8LS-CP
8LS User’s Guide 107
The 8LS-CP is not only ordered for the number of carbon input loops
desired, but the CPU DIP Switch on the CPU board must be set
correctly to reflect the number of carbon inputs.
The figure below presents a typical 8LS-CP control system.
Number of Carbon Loops
CPU DIP Switch
#7 #8
CP-1 Off Off
CP-2 Off On
CP-3 On Off
CP-4 On On
8 loop controller
Probe T/C
Carbon probe
Furnace/Generator
Furn T/C
Loop #1 Probe temperature input
Loop #2 Carbon input
T/C
Loop #3
Furnace temperature control
Furn heat control
Loop #1 or #3 PID primary output
Reverse Action TP or analog
Gas valve
Atmosphere
Control
Loop #2 PID primary output
Reverse action TP or analog
SSR
Relay
N.C.
Air valve
Atmosphere
Control
DAC
SSR
Air flow
regulator N.C.
Probe
air
supply
GAS
AIR
Burn -off
solenoid valve
To carbon probe
burn-off port
To carbon probe
reference port
Requires DAC for
analog output
Loop #2 PID secondary output
Direct Action TP only
CP gas shut off valve.
Closed when loop #1 PV(1400 or PV>2400ºF.
1400-2400
CO+CO2: 1-30%
Alternate
must use digital
CP gas output
Generator
.
Connection
for
Temperature
Control
External
High limit
CP
trim gas
digital
output Probe
Burn off
digital
output
Supply
Supply
120 VAC
Supply