Daikin MicroTech III DPS - Alternate Heating Initialization (16-28 Tons); Alternate Initialization (16-28 Tons)

OM 1263 • MICROTECH UNIT CONTROLLER 64 www.DaikinApplied.com
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Table 44: Alternate Initialization Sequence, 16–28 Tons
Device Step 1 Step 2 Step 3 Step 4
Inverter Compressor & Comp3
Inverter Compressor Speed =
Minimum Comp3 = O󰀨
Inverter Compressor Speed =
Step 2 Comp3 = O󰀨
Inverter Compressor Speed
= Increasing 1 step every 5
seconds if PTD-PTD < 26 PSI
Comp3 = O󰀨
A
Inverter Compressor Only
Inverter Compressor Speed =
Minimum
If OAT ≤59°F, Inverter
Compressor Speed = Smaller
of Step 12 or Maximum
If OAT >59°F, Inverter
Compressor Speed = Minimum
A NA
Outdoor Fan Outdoor Fan = 100% ← ← ←
4 Way Valve (Heat Pump) ON ← ← ←
Outdoor Coil
Expansion Valve (EVO)
(Heat Pump only)
B ← ← ←
Time Duration 5 Seconds 5 Seconds C ←
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 o󰀨 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 (di󰀨erential pressure above 57 psi) and superheat is above 18°F or discharge pressure is
above 384 psi.