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

OM 1263 • MICROTECH UNIT CONTROLLER 62 www.DaikinApplied.com
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Table 42: Standard 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󰀨
D
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
← D
Outdoor Fan Outdoor Fan = 100% ← ← ←
4-Way Valve (Heat Pump) ON ← ← ←
Outdoor Coil
Expansion Valve (EVO)
(Heat Pump only)
EVO = 0% A ← ←
Time Duration 10 Seconds 5 Seconds C B
A. The outdoor expansion valve is to keep the suction superheat between 3.6°F and 12°F.
B. Standard initialization lasts a maximum of 600 seconds. It is completed early anywhere between 10 and 600 seconds if
discharge pressure is high (above 384 psi) or the 4-way valve has been seated for 60 seconds (di󰀨erential pressure above
57 psi).
C. Step 3 ends when the minimum Step 16 is reached, di󰀨erential pressure is greater than 26 psi for 3 seconds, or 3 minutes
have elapsed since the start of step 3.
D. Inverter compressor speed is increaded until the 4-way valve is seated (discharge minus suciton pressure > 57 psi).
Comp3 is always OFF.
See page 50 for more information about what is a compressor “step”.