Liebert iCOM Microprocessor TM-10098 - Manual (Page 116)

iCOM
Control Training and Service Manual
115
The temperature sensor senses a rise in temperature. The rise is transmitted to
the Central Processing Unit (CPU). The CPU looks into its memory for information
and instructions on what to do with the rise in temperature. The CPU then makes
the decision to call for cooling.
Isolation
We use the opto-isolator and the triac to isolate areas of control and voltage.
There are three areas of control and two voltage levels. Digital control comes from
the microprocessor at 5 VDC and the other voltage level is 24 VAC. One voltage
is used to turn on the triac and the other is used to operate the load device.
Areas of Control
OPTO
TRIAC
Transformer
Power 24 VAC
DIGITAL
CONTROL POWER
Processor
5 VDC Signal
5 VDC
Ground
ISOLATION ISOLATION
Transformer
Power 24 VAC
Load
Device