Service manual

13-3
CONTROL SYSTEM
SM DLF 1-A.1 GB
Target frequency limits as a function of outdoor air temperature (OAT):
OAT Range Cooling Mode limits Heating Mode limits
OAT < 6
MaxFreqAsOATC
No limit
6 ≤ OAT < 15 MaxFreqAsOAT1H
15≤ OAT<28
MaxFreqAsOAT2H
28≤ OAT No limit
13.1.4 Frequency Changes Control
When the unit is running normally , the compressor frequency change rate is 1 Hz/sec.
13.1.5 Compressor Starting Control
13.1.5.1 Compressor starting control for DCI25/35/50/60
Time
Step1
Step2
Step3
Min 10 Minutes
1
Minute
1
Minute
13.1.5.2 Compressor starting control for DCI72Z
Step 1
Whenever the compressor starts up, after it has been off for more than 45 minutes, the compressor
frequency cannot go below Step1RPS for 3 continuous minutes (this rule comes to ensure oil return
to the compressor).
Step 2
The compressor speed cannot go above Step2RPS once after each compressor start up for 3
continuous minutes (this rule comes to prevent oil exit from the compressor after its start up).
Step 3
The speed cannot go higher than Step3RPS unless it was operating for more than 1 continuous
minutes between Step3RPS – 5 and Step3RPS .
After passing above Step3RPS, this rule is re-applied when passing below Step3RPS-5.
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