Instruction Manual

93
pattern according to the capacity demand
signal of the system. The following table
shows the linear relationship between the
demand signal and compressor capacity
modulation. The compressor controller
protects the compressor against high
discharge temperature. Refer to Appendix B
for the relationship between thermistor
temperature readings and resistance values.
Table 28 - Demand Signal vs. Compressor Capacity Modulation
Demand
Signal (VDC)
Loaded %
Unloaded %
Time Loaded
Time
Unloaded
% Compressor
Capacity
1.00
Off
Off
Off
Off
0%
1.44
10%
90%
1.5 sec
13.5 sec
10%
3.00
50%
50%
7.5 sec
7.5 sec
50%
4.20
80%
20%
12 sec
3 sec
80%
5.00
100%
0%
15 sec
0 sec
100%
Figure 50 - Compressor Controller Flash Code Details
Filter Replacement
Monthly air filter inspection is required to
maintain optimum unit efficiency.
It is strongly recommended that filter media
be replaced monthly. Filters are located
upstream of the evaporator coil in the filter
and economizer section. Open access door
and pull filters straight out to inspect all of
the filters. Replace filters with the size
indicated on each filter or as shown in the
tables below. Arrow on the replacement
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.
WARNING