Daikin MicroTech III DPS Installation And Maintenance Manual page 64

Table 44: Alternate Initialization Sequence, 16–28 Tons
Device
Inverter Compressor & Comp3
Inverter Compressor Only
Outdoor Fan
4 Way Valve (Heat Pump)
Outdoor Coil
Expansion Valve (EVO)
(Heat Pump only)
Time Duration
A . Inverter compressor speed is increased until the 4-way valve is seated (discharge minus suction pressure > 57 psi) and as
long as discharge presure is below 221 psi . Inverter compressor speed is also increased if the discharge pressure remains
below 171 psi . Comp3 turns on if the inverter compresor speed is at maximum and those conditions are not met . Comp3
turns back off after 20 seconds if the discharge pressure rised above 221 psi.
B . The outdoor expansion vavle is to keep the suction superheat between 3 .6°F and 5 .4 °F
C . Alternate initializaiton lasts a maximum 15 minutes. It is completed early anywhere between 10 seconds and 15 minutes if
once the 4-way valve is seated (differential pressure above 57 psi) and superheat is above 18°F or discharge pressure is
above 384 psi .
OM 1263 • MICROTECH UNIT CONTROLLER
Step 1
Inverter Compressor Speed = Inverter Compressor Speed =
Minimum Comp3 = Off
Compressor Speed = Smaller
Inverter Compressor Speed =
Minimum
Compressor Speed = Minimum
Outdoor Fan = 100%
ON
B
5 Seconds
Step 2
Inverter Compressor Speed
= Increasing 1 step every 5
Step 2 Comp3 = Off seconds if PTD-PTD < 26 PSI
If OAT ≤59°F, Inverter
of Step 12 or Maximum
If OAT >59°F, Inverter
←
←
←
5 Seconds
64
Step 3
Comp3 = Off
A
←
←
←
C
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Heat Pump
Step 4
A
NA
←
←
←
←